Rosnah Mohd Zain

Abstract: This paper proposes an adaptive technique in the prediction of dichotomous response variable by combining fuzzy concept with statistical logistic regression. The model was tested on an oral cancer dataset in predicting oral cancer susceptibility. In this paper we will present the development, evaluation and validation of the proposed model based on the experiment carried out. Explanatory power of the adaptive model was calculated and compared with fuzzy neural network and statistical logistic regression models using calibration and discrimination techniques. Area under ROC values calculated indicates that the proposed model has compatible predictive ability to both fuzzy neural network and statistical logistic regression models. �© 2007 IEEE.

Abstract: Objectives. We investigated the population burden of betel quid abuse and its related impact on oral premalignant disorders (OPDs) in South, Southeast, and East Asia. Methods. The Asian Betel-Quid Consortium conducted a multistage sampling of 8922 representative participants from Taiwan, Mainland China, Malaysia, Indonesia, Nepal, and Sri Lanka. Participants received an interviewer-administered survey and were examined for oral mucosal disorders. Results. The prevalence of betel quid abuse was 0.8% to 46.3% across 6 Asian populations. The abuse frequency was over 40.5% for current chewers, with the highest proportion in Nepalese and Southeast Asian chewers (76.9%?99.6%). Tobacco-added betel quid conferred higher abuse rates (74.4%?99.6%) among Malaysian, Indonesian, and Sri Lankan men than did tobacco-free betel quid (21.8%?89.1%). Gender, lower education level, younger age at chewing initiation, and clustering of familial betel quid use significantly contributed to higher abuse rates. Indonesian betel quid abusers showed the highest prevalence of OPDs and had a greater risk of OPDs than did nonabusers. Conclusions. Betel quid abuse is high in regions of Asia where it is customarily practiced, and such abuse correlates highly with OPDs. By recognizing abuse-associated factors, health policies and preventive frameworks can be effectively constructed to combat these oral preneoplasms.

Abstract: Introduction: The risk of cancer has been extensively investigated with the intake of single food items but food consumption in an individual is usually complex, made up by combinations of different food items. This study aims to identify dietary patterns of Malaysians, and establishing relationship between dietary pattern and oral cancer risk. Methods A hospital-based, case-control study was conducted on 300 Malaysians who seek treatment at participating hospitals between January 2003 and December 2010. The subjects consisted of 150 cases and 150 controls that were matched for gender, age (5 years) and ethnicity. Dietary intake was measured using Food Frequency Questionnaire (FFQ). Factor Analysis (FA) was performed to identify dietary consumptions pattern based on the intake of nine major food groups. Logistic Regression was done to compute the odds ratio (OR) for the components retained by FA. Results: FA had identified four patterns that accounted for 69.4% of total variability within the sample. The first pattern labeled as �modern� was loaded with processed foods and snacks intakes whereas the second pattern �prudent� was characterized by the intakes of fruits and vegetables. The third pattern �traditional� consisted of beverages and starches intakes while the fourth pattern �combination� was loaded with intakes of dairy foods, fermented foods and meat/byproducts. A significant reduced risk was found for �prudent� (aOR 0.42, 95%CI: 0.21�0.83, p < 0.05), whereas a significant increased risk was found for both �traditional� (aOR 2.06, 95%CI: 1.05�4.02) and �combination� (aOR 3.45, 95%CI: 1.75�6.77, p < 0.05) pattern. Discussion: These findings suggest that intake of �prudent� pattern may confer protection against oral cancer risk of up to 58% whereas the highest consumption of both �traditional� and �combination� pattern may induce twice and thrice the risk of oral cancer. FA was also found to be a useful tool to identify dietary pattern and its relationship with oral cancer.

Abstract: Introduction: ALDH2 is an enzyme involved in major oxidative pathway of alcohol metabolism while GSTM1 is a drug-metabolizing enzyme of acetaldehyde. It has been reported that the mutant ALDH2 allele and the absence of GSTM1 contributes to increased oral cancer risk due to reduced acetaldehyde metabolism. This study aims to determine ALDH2 and GSTM1 polymorphisms and its association with oral cancer risk. Method: An unmatched case-control study was conducted using 163 oral cancer patients and 87 non-cancer subjects selected from the OCRCC database. ALDH2 and GSTM1 genotypes were determined using PCR-RFLP from peripheral blood. Multiple logistic regression was employed to assess association between polymorphisms and oral cancer risk. Results: Most common risk habit was betel-quid chewing (44.0%), followed by smoking (30.4%) and alcohol drinking (29.6%). The prevalence of ALDH2 polymorphism is only 5.7%, while GSTM1 null is seen in 51.2%. Alcohol drinking and the combination of ALDH2 polymorphism and alcohol consumption is significantly associated with increased risk of oral cancer (p < 0.001). Discussion: In this population, although the prevalence of alcohol consumption is low compared to other populations, alcohol drinking has been found to significantly increase oral cancer risk, even after adjusting for confounding factors (age, gender and ethnic) (aOR 6.8, 95% CI 2.6, 18.1). The prevalence of ALDH2 polymorphism was found to be much lower compared to other Asian population such as the Japanese and Taiwanese. In relation to oral cancer risk, no significant association was seen for both the polymorphisms of ALDH2 and GSTM1. However, when analysis was done for the combination of ALDH2 polymorphism and alcohol consumption, those who concurrently exhibit ALDH2 polymorphism and consumed alcohol was found to be 6 times more likely to develop oral cancer (aOR 6.6, 95% CI 2.4, 17.9). No such association was observed for the combination of GSTM1 polymorphism and alcohol consumption. In conclusion, alcohol consumption is a significant independent risk factor for oral cancer among Malaysians while ALDH2 polymorphism together with the habit of alcohol drinking also confers an increased risk for oral cancer.

Abstract: Introduction: ITCs found in cruciferous vegetables has been reported to reduce cancer risk by inducing phase II conjugating enzymes, in particular GSTs. Interestingly, these enzymes also metabolize ITCs therefore; the protective effects of ITCs would depend on the activity of GSTs. This study aimed to determine association between dietary ITCs, GSTs polymorphisms and risk habits (cigarette smoking, alcohol drinking and betel-quid chewing) with oral cancer. Method: Included in this study were 115 OSCC patients and 116 healthy subjects. Information on ITC intake from cruciferous vegetables was collected via a semi-quantitative FFQ. Peripheral blood lymphocytes were obtained for genotyping of GSTM1, GSTT1 and GSTP1 using PCR multiplex and PCR-RFLP. Chi-square and logistic regression were performed to determine the association of ITC and GSTs polymorphism and risk of oral cancer. Results: When dietary ITC was categorized into high (greater than/equal to median) and low (less than median) intake, ITC consumption was higher among cases (51.3%) than controls. However, it was not statistically significant (p = 0.645). Discussion: Odd ratios analysis showed no significant association between ITC intake, GSTM1, GSTT1 or GSTP1 genotypes with oral cancer risk. However, GSTP1 wild-type was associated with later disease onset in women above 55 years of age (p = 0.017). Among men above 45 years of age, there was a significant 17-year difference in the age of OSCC onset between those with GSTP1 wild-type + low ITC intake and GSTP1 polymorphism + high ITC intake (p < 0.001). Similarly further analysis stratified by risk habits (drinking and chewing), showed that GSTP1 polymorphism + high ITC intake was associated with earlier disease onset (p < 0.001). This study suggests that combinatory effects between dietary ITCs, GSTP1 polymorphism and risk habits may be associated with risk of oral cancer and modulate the age of disease onset. Copyright �© 2011 Published by Elsevier Ltd.

Abstract: BACKGROUND AIMS. Dental pulp stromal cells (DPSC) are considered to be a promising source of stem cells in the field of regenerative therapy. However, the usage of DPSC in transplantation requires large-scale expansion to cater for the need for clinical quantity without compromising current good manufacturing practice (cGMP). Existing protocols for cell culturing make use of fetal bovine serum (FBS) as a nutritional supplement. Unfortunately, FBS is an undesirable additive to cells because it carries the risk of transmitting viral and prion diseases. Therefore, the present study was undertaken to examine the efficacy of human platelet lysate (HPL) as a substitute for FBS in a large-scale set-up. METHODS. We expanded the DPSC in Dulbecco's modified Eagle's medium-knock-out (DMEM-KO) with either 10% FBS or 10% HPL, and studied the characteristics of DPSC at pre- (T25 culture flask) and post- (5-STACK chamber) large-scale expansion in terms of their identity, quality, functionality, molecular signatures and cytogenetic stability. RESULTS. In both pre- and post-large-scale expansion, DPSC expanded in HPL showed extensive proliferation of cells (c. 2-fold) compared with FBS; the purity, immune phenotype, colony-forming unit potential and differentiation were comparable. Furthermore, to understand the gene expression profiling, the transcriptomes and cytogenetics of DPSC expanded under HPL and FBS were compared, revealing similar expression profiles. CONCLUSIONS. We present a highly economized expansion of DPSC in HPL, yielding double the amount of cells while retaining their basic characteristics during a shorter time period under cGMP conditions, making it suitable for therapeutic applications.

Abstract: Health risks stemming from betel-quid (BQ) chewing are frequently overlooked by people. Updated epidemiological data on the increased BQ use among Asian populations using comparable data collection methods have not been widely available. To investigate the prevalence, patterns of practice and associated types of oral preneoplastic disorders, an intercountry Asian Betel-quid Consortium study (the ABC study) was conducted for Taiwan, Mainland China, Malaysia, Indonesia, Nepal and Sri Lanka. A random sample of 8,922 subjects was recruited, and the data were analyzed using survey-data modules adjusted for the complex survey design. Chewing rates among men (10.7-43.6%) were significantly higher than women (1.8-34.9%) in Taiwan, Mainland China, Nepal and Sri Lanka, while women's rates (29.5-46.8%) were higher than that for men (9.8-12.0%) in Malaysia and Indonesia. An emerging, higher proportion of new-users were identified for Hunan in Mainland China (11.1-24.7%), where Hunan chewers have the unique practice of using the dried husk of areca fruit rather than the solid nut universally used by others. Men in the Eastern and South Asian study communities were deemed likely to combine chewing with smoking and drinking (5.6-13.6%). Indonesian women who chewed BQ exhibited the highest prevalence of oral lichen planus, oral submucous fibrosis and oral leukoplakia (9.1-17.3%). Lower schooling, alcohol drinking and tobacco smoking were identified as being associated with BQ chewing. In conclusion, the ABC study reveals the significant cultural and demographic differences contributing to practice patterns of BQ usage and the great health risks that such practices pose in the Asian region.

Abstract: Introduction: Western researchers showed that oral squamous cell carcinoma (OSCC) patients exhibit lower survival rate and poorer prognosis compared to other type of cancer where several clinicopathological parameters have been implicated in the survival of patients. This study aims to assess the association between sociodemographic and clinicopathological parameters with survival of OSCC patients. Method: Data were collected from 253 histologically diagnosed OSCC patients attending selected clinics nationwide. Survival was analyzed for relation with habits, site, disease stage and nodal involvement. Results: Mean age was 58.9 �± 12.6 years with 8.3% aged less than 40. Majority is females (61.1%) and of Indian ethnic (48.0%). Most common habit was quid chewing (55.8%), followed by smoking (29.7%) and most came at stage IV (44.3%). Tongue was the most common site (38.9%), followed by buccal mucosa (35.0%). Factors associated with survival are smoking (p = 0.016), stage at presentation (p < 0.001) and nodal involvement (p < 0.001). Discussion: Majority of OSCC cases occurred among Indians where the patients were quid chewers and presents with advanced cancer. Survival of patients decreased steadily over the years. At 1 year after diagnosis, 67.2% was still alive but only 13.4% survived 5 years. Among the habits studied, only smoking was found to be associated with survival where among those smoking, only 38.7% is alive compared to 61.3% deceased. No association was found between site and survival. A highly significant association was seen for both cancer stage and nodal involvement with survival. More survivors were found among those who come at early stage (76.3%) compared to late stage (32.7%). Similarly, more than two thirds (69.1%) of those who present with negative nodal involvement were found to be alive. In conclusion, smoking, disease stage and nodal status are predictors of survival for OSCC patients in Malaysia.

Abstract: Introduction: Tongue and cheek cancer have different behaviors. In order to understand these behaviors, there is a need to look into the chromosomal alterations and gene pathways that maybe associated with oral cancer at these sites. Therefore, the objective of this study is to determine the differences in chromosomal aberrations and gene pathways involved in tongue and cheek cancer using high resolution array CGH. Methods: A genome wide screening with array CGH (SurePrint G3 CGH 1x1M microarray) was performed using gDNA from 20 snap frozen fresh tissues consisting of 12 tongue and 8 cheek oral squamous cell carcinomas (samples from the Malaysian Oral Cancer Data and Tumour Bank System [MOCDTBS] coordinated by OCRCC-UM). Cytosure Software was used to detect the chromosomal aberrations and candidate genes related to the selected regions. Pathway analysis was done using MetaCoreâ�¢software for selected genes. Results: The mean number of chromosomal aberrations per tumour for tongue cancer (22 �± 24.97) was higher than cheek cancer (8.38 �± 11.98). The most common amplified regions in tongue cancers were 8q24.22 (33.33%), 8q24.3 (33.33%), 11q13.1 (33.33%), 11q13.2 (33.33%), 12q13.13 (33.33%), 14q32.33 (33.33%) and for cheek cancer the most common amplified region was 22q12.3 (25%). For the deleted regions, the most common for tongue cancer were 2q21.1 (16.67%), 6q21 (16.67%) and for cheek cancer were 2q22.1 (25%), 7q35 (25%), 19q13.33 (25%). The most significant pathway based on p < 0.001 involved in tongue cancer is cell adhesion ECM remodeling pathway Among the genes involved in amplified region, were EGFR, MMP1, MMP10, MMP12, MMP3, MMP7 and MMP9. For cheek cancer, the cancer associated significant pathway was apoptosis and survival (the role of CDK5 in neuronal death and survival). An oncogene located at 8p12 was identified in this pathway is NRG1. Discussion: This study showed a different pattern of chromosomal aberrations in tongue and cheek cancer with different significant gene pathways. Tongue cancer behaves more aggressively than cheek cancer which may be due to the involvement of ECM remodeling pathway, where MMP family which are the proteolytic enzyme that degrade various component in the extracellular matrix would favor invasion and metastasis.

Abstract: Introduction: The variability of clinical outcomes in oral cancer patients and the heterogeneity of the disease are the main challenges for the improvement of current treatment modalities. Efforts in our laboratory have focused on the molecular profiling of oral cancer to understand the mechanisms underlying the disease. In a previous microarray study, we found Guanine nucleotide binding protein alpha-12 (GNA12) to be up-regulated in oral cancer. Materials and methods: In this study, we validated the expression of GNA12 at the mRNA level in 47 oral squamous cell carcinoma (OSCC) and 18 non-malignant oral mucosa tissues, by quantitative polymerase chain reaction (qPCR). Further, GNA12 protein expression was accessed by immunohistochemistry (IHC) on 44 tumors and 23 non-malignant oral mucosa tissues. Using OSCC cell lines, we examined the effects of GNA12 signaling by in vitro functional assays. Results: We demonstrated that GNA12 mRNA levels were significantly up-regulated in OSCC in comparison to the non-malignant oral mucosa tissues. Consistently, high levels of GNA12 protein expression were detected in 75% of OSCC tissues, while the non-malignant tissues showed negative or weak expression. We demonstrated that expression of activated GNA12 (GQ231L) promoted oral cancer cell migration in a monolayer wound healing assay and cell invasion through the matrigel barrier, but cell proliferation was not changed. Correspondingly, exogenous expression of the regulator of G-protein signaling (RGS) blocked G12 family signaling through RhoA, which resulted in the inhibition of cancer cell migration and invasion. Discussion: In summary, we demonstrated for the first time in OSCC that GNA12 is over-expressed in a large percentage of these patients and notably, the over-expression drives migration and invasion of oral cancer cells. Taken together, this information indicates that targeting GNA12 could benefit oral cancer patients by preventing the spread of the disease.

Abstract: It is well established that a plethora of mutations that occur in oncogenes and tumor-suppressor genes are the main drivers of tumorigenesis. The identification of these mutations provides important clues to the cellular processes of carcinogenesis and affords an opportunity for these genes to be used for diagnostic and therapeutic purposes. In comparison to cancers such as breast, lung and colorectal, there is a lack of systematic, large scale characterization of oncogenic mutations oralsquamous cell carcinoma (OSCC).

Abstract: Introduction: Several molecular markers have been studied for their usefulness as prognostic markers in oral squamous cell carcinoma (OSCC). One such molecular marker is cyclin D1 which is a proto-oncogene located on 11q13 in humans. Objective: To explore the feasibility of using cyclin D1 as a prognostic marker in tongue and cheek SCC by the fluorescent-in-situ hybridization (FISH) method. Methods: Fifty paraffin-embedded samples (25 each of cheek and tongue SCCs) were obtained from the archives of the Oral Pathology Diagnostic Laboratory. Sociodemographic data, histopathologic diagnoses, lymph node status and survival data were obtained from the Malaysian Oral Cancer Database and Tissue Bank System (MOCDTBS)coordinated by the Oral Cancer Research and Coordinating Centre (OCRCC), University of Malaya. The FISH technique was used to detect the amplification of cyclin D1 using the Vysis protocol. Statistical correlations of cyclin D1 with site and lymph node status were analyzed using the Fisher exact test. Kaplan-Meier and Log Rank (Mantel-Cox) test were used to analyze cyclin D1 amplification and median survival time. Results: Positive amplification of cyclin D1 was detected in 72% (36) of OSCCs. Detection of positive amplification for cyclin D1 was observed in 88% (22) and 56% (14) of the tongue and cheek tumors, respectively, where the difference was statistically significant (P=0.012). Lymph node metastasis of cheek SCCs showed a trend towards a significant association (P= 0.098) with cyclin D1 amplification whereas the lymph node metastasis of tongue SCC was clearly not significant (P=0.593).There was a statistically significant correlation between cyclin D1 positivity and survival rate (P=0.009) for overall SCC cases and (P<0.001) for cheek SCC cases. Conclusion: The present study found that cyclin D1 amplification may differ in different subsites of OSCC (tongue vs cheek) and its positive amplification implies an overall poor survival in OSCCs, particularly those arising in cheeks.

Abstract:

Abstract: Betel quid chewing is a common habit widely practiced in Southern Asian populations. However, variations are seen in the content of a betel quid across the different countries. Factors associated with commencement and cessation of this habit has been numerously studied. Unfortunately, data on Malaysian population is non-existent. This study aims to determine the factors associated with the inception and also cessation of betel quid chewing behaviour among Malaysian adults.

Abstract: Introduction: HPV infection has been associated with a subset of head and neck cancers and current evidence suggest that it may be an important risk factor for oral cancer. Using polymerase chain reaction (PCR) and sequencing, we recently demonstrated the presence of HPV in more than 50% of oral squamous cell carcinoma (OSCC) patients and that high-risk HPV is significantly associated with OSCC. Serological detection of HPV has been reported the most convenient method for detecting HPV. However, currently there is a lack of serological assays for the detection of the HPV. The HPV E6 viral oncoprotein is known to play crucial role in tumorigenesis, therefore detecting the presence of the E6 protein could be a useful biomarker for HPV detection.Methods: A pGEX plasmid containing HPV 16 E6 gene was ligated with KT3 oligonucleotide. Constructed plasmid was then transformed into Escherichia coli for production of the recombinant protein which was used as antigen in ELISA assay. ELISA was optimized using anti KT3 antibody to detect the recombinant antigen. HPV ELISA was performed on sera from 18 healthy and 15 OSCC patients obtained from the Malaysian Oral Cancer Database & Tissue Bank System (MOCDTBS) which is coordinated by Oral Cancer Research & Coordinating Centre (OCRCC). Sera that have net OD above calculated cutoff value were determined as HPV seropositive. Fisher�s Exact test was used for statistical evaluation.Results: An ELISA method to detect the presence of HPV16 E6 protein was successfully developed. Using this method, 33.3% (5/15) of OSCC and 16.7% (3/18) of healthy patients were found to be HPV 16 seropositive. No significant association was found between HPV 16 seropositivity and OSCC occurrence (P value = 0.428).Discussion: Although there is a trend to support our previous findings using PCR where a larger proportion of OSCC patients were HPV positive in comparison to healthy individuals, our results using ELISA method did not show any statistical significance. This remains to be tested in a larger sample set to confirm pur preliminary result that could more representative of our patient population.

Abstract: Introduction: Oral cancer is a debilitating disease and the survival rates for these patients have not improved over the past decades. Tobacco smoking is one of the most common risk factor associated with oral cancer. Objectives: To explore and identify differential genes expression associated with tobacco smoking. Methodology: Next generation sequencing using the Illumina Genome Analyzer was done to sequence five fresh frozen oral cancer tissue samples from smoking patients, two of which were former smoker and an additional 8 samples consisting of normal oral mucosal tissues from the alveolar mucosa of non-cancer patients where 4 were smokers and another 4 were non-smokers. The tissues and socio- demographic information were obtained from the Malaysian Oral Cancer Data and Tumour Bank System (MOCDTBS) at the Oral Cancer Research and Coordinating Centre (OCRCC). High quality poly A+ RNA was extracted from macrodissected tumour and normal epithelial tissue to obtain >70%. Validation of second generation sequencing was done using commercial and custom microarrays. Principle component analysis (PCA) was applied to the sequenced generated data. Results and discussion: PCA showed distinct clusters separating groups of current and former smokers. The former smoker who ceased smoking >25 years clustered closely with normal non-smoker suggesting expression levels of some of the genes related to tobacco smoking could return to levels similar to never smokers upon cessation of smoking. When comparing differential gene expression between tumor in former and current smokers, ACTC1, MYH2, DES, MYBPH, MYLPF were the top 5 most down-regulated genes. Meanwhile, CYP2W1, FAIM2, OLFML1, KRT13 were found to be up-regulated when comparing differential gene expression between these groups (fold change > 8). Despite prolonged smoking cessation, some gene expression could appear to be permanently altered and these irreversible changes may account for oral cancer risk despite smoking cessation. Conclusion: These findings illustrate the potential for next generation sequencing to provide insights into the unique gene expression profiles associated with risk habits which will be useful in developing biomarkers for prognostic and therapeutic applications in the future.

Abstract: The incidence of oral cancer is high for those of Indian ethnic origin in Malaysia. Various clinical and pathological data are usually used in oral cancer prognosis. However, due to time, cost and tissue limitations, the number of prognosis variables need to be reduced. In this research, we demonstrated the use of feature selection methods to select a subset of variables that is highly predictive of oral cancer prognosis. The objective is to reduce the number of input variables, thus to identify the key clinicopathologic (input) variables of oral cancer prognosis based on the data collected in the Malaysian scenario. Two feature selection methods, genetic algorithm (wrapper approach) and Pearson's correlation coefficient (filter approach) were implemented and compared with single-input models and a full-input model. The results showed that the reduced models with feature selection method are able to produce more accurate prognosis results than the full-input model and single-input model, with the Pearson's correlation coefficient achieving the most promising results.

Abstract: NK/T cell lymphoma is a destructive extranodal lymphoproliferative disorder of a putative natural killer (NK) cell lineage. This rare malignant lymphoma is dif�cult to diagnose due to the histological resemblance to reactive processes hence was once considered as an in�ammatory lesion known as lethal midline granuloma or non-healing granuloma. Providentially, the advance in immunophenotyping has permit characterization of NK/T-cell lymphoma, as a distinct entity from other type of lymphoma. It is most commonly involved the nasal cavity, paranasal sinuses and hard palate and as the case we reported here of a NK/T-cell lymphoma in a 29 year old Indonesian man whom presented with an ulcer on the palate. The ulcer started on the pharynx and progressively involved the soft and hard palate. Eventually, the whole palate appeared necrosed with granulation tissue and the uvula was elongated and irregular.Immunohistochemical studies leads to the diagnosis of an extranodular NK/T cell lymphoma

Abstract: Introduction: Dietary intake has been hypothesized to be associated with various diseases including oral cancer. According to studies worldwide, imbalanced diet and nutrient deficiency have been attributed to promote oral malignancies. However, the function of specific nutrients in preventing oral cancer remains largely undefined. This study aims to investigate the association between intake of retinol and vitamin C with the risk of oral cancer. Materials and methods: Dietary intake data was collected from 8 participating hospitals throughout Malaysia using a validated foodfrequency questionnaire (FFQ). Intake of retinol and vitamin C were computed using the Nutriemart software. This case-control study included 150 cases and 150 controls matched for age, gender and ethnicity.The association between micronutrients, risk habits and oral cancer was analysed using Pearson Chi-Square test and multiple logistic regression. Results: Significantly more controls were found to consume retinol (27.3%) and vitamin C (83.3%) above the Recommended Daily Allowance (RDA) as compared to cases (10.7% and 72.0%, respectively). Among risk habits, only cigarette smoking was found to have an inverse association with vitamin C (p = 0.021) where as no risk habits were found to be associated with retinol intake. After adjusting for confounding factors, only retinol intake was found to be inversely related to the risk of oral cancer (aOR 0.272, 95%CI 0.135� 0.548). Discussion: This study suggests that vitamin C appears to reduce risk of oral cancer and this relationship is weakened after adjusting for risk habits. Meanwhile, retinol intake proves to provide protection against oral cancer up to 72.8% independent of risk habits practiced.

Abstract: Introduction: MicroRNAs (miRNAs) have previously found to be highly tissue- or disease-specific biomarkers with clinical applicability. However, the role of miRNAs in OSCC progression has yet to be well-studied. Here, we demonstrated the use of FFPE specimens in microarray profiling and quantitative real-time PCR (qPCR) approaches to identify miRNAs that are differentially expressed in OSCC compared with non-tumour tissues.Materials and methods: Four OSCC and four non-tumour FFPE tissues were obtained from the Malaysian Oral Cancer Database and Tumour System (MOCDTBS), coordinated by OCRCC-UM and profiled using Agilent 8 �� 15 k mammalian miRNA microarray. Based on microarray results, TaqMan miRNA Assay (qPCR) is underway to validate the selected differentially expressed miR-31, miR-7, miR-375 and miR-151-3p with an endogeneous control RNU-44 using an independent set of FFPE tissue (seven OSCC and three non-tumuor tissues). Biological functions of targeted miRNAs were analyzed using GeneGO Pathway software.Results: Analysis of profiling identified 19 significantly up-regulated miRNAs (2-fold change) and four significantly down-regulated miRNAs (2-fold change). The targeted miR-31, miR-7 and miR-151-3p were up-regulated whilst miR-375 was down-regulated in OSCC compared with non-tumour tissues. These initial microarray profiling results had been subsequently confirmed in qPCR validation except miR-151-3p, which was validated as down-regulated miRNA.Discussion: Interestingly, we have identified miRNA targets that can potentially be exploited to differentiate between betel-quid exposure OSCC with no risk habit related OSCC. These miRNA targets were found to interact with protein BuBRl in regulation of cellular component organization (p0.05, GeneGo Pathway software). BuBR1 can be modified by arecoline in betel nut leads to abnormal cell cycle progression. Further analyses with larger sample set are on-going to validate the preliminary result and examine if the betel-quid exposures related with OSCC carcinogenesis may be acting through a specific miRNA alterations to lead to a malignant phenotypes. This better understanding of the contribution of miRNA to OSCC may aid in earlier diagnosis, improved prognosis, and novel targets for therapeutic intervention.

Abstract: The modified preparation technique developed in the present study has provided an excellent chromosome metaphase spread from the whole body of larvae of the red hybrid tilapia Oreochromis mossambicus (Peters, 1852) X Oreochromis niloticus (Linnaeus, 1758). Unlike other chromosome preparation methods, this modified technique showed a reduction in cell loss while suspending cells during the dropping process. This modified technique can therefore be widely applied not only to various tilapias but also to other teleostean fishes for preparing chromosome spreads. The best treatment parameters for preparing good chromosome spreads from red hybrid tilapia were optimized as 0.01% concentration of colchicine for 4-6 hours, hypotonic 40 minutes treatment, fixation with carnoy solution at 3:1 ratio and a concentration of 10% Giemsa for 20 minutes.

Abstract: Purpose: The purpose of this study was to evaluate the role of HPV and p53 polymorphisms in oral squamous cell carcinomas (OSCC) affecting Malaysian population. Methods: We analysed frozen samples from 105 OSCC as well as 105 oral specimens derived from healthy individuals. PCR assays targeting two regions of the virus were used. PCR amplification for the analysis of p53 codon 72 arginine/proline alleles was carried out in a separate reaction. Results: HPV DNA was detected in 51.4% OSCC samples, while 24.8% controls were found to be HPV positive. HPV was found to be significantly associated with OSCC (P < 0.001, OR = 4.3 after adjustment for habits) when compared to controls. High-risk HPV was found to be significantly associated with OSCC cases (P < 0.05). Demographic profiles of age, gender, race and habits were not associated with HPV presence in cases and controls. However, significantly less HPV positivity was seen in poorly differentiated compared to well-differentiated OSCCs. No significant association was found between HPV positivity and p53 polymorphisms in cases and control groups. Additionally, we found no association of codon 72 polymorphism with oral cancer. Conclusions: This study indicates that high-risk HPV infection is one of the contributing factors for OSCCs. HPV 16 was the predominant type found in Malaysian patients with OSCC. Further, we did not find any association between p53 codon 72 polymorphism and HPV infection or between the p53 polymorphism and the risk of oral cancer.

Abstract: Introduction: MDM2 is a negative regulator of the p53 tumor suppressor protein. The presence of a variety of MDM2 splice variants have been reported in many different types of tumor and some have been shown to be associated with patient prognosis.Materials and methods: In this study, we demonstrated the occurrence of MDM2 splice variants in OSCC tissues. RNA was extracted from 45 OSCC tissues and 17 normal oral mucosa tissues and reverse transcribed into cDNA. Nested PCR was performed to amplify the MDM2 transcripts and the PCR amplicons were cloned into cloning vector pTZ57R/T and sequenced.Results: We demonstrated that 37/45 OSCC and 14/17 normal oral mucosa tissues contained MDM2 splice variants and a total of 34 transcript variants were found. Comparing with the reported splice variants in GenBank, four known variants, MDM2B, MDM2C, MDM2-EU2 and MDM2-PM2 were found in tumor samples with MDM2B being the most common variants found in our samples. None of these known variants were found in normal oral mucosa tissues. The other 30 transcript variants were novel, where 3 of these were present in both tumor and normal tissues, 23 were found only in tumor tissues and 4 were exclusive to normal oral mucosa tissue.Discussion: The common loss among the variants was sequences coding for the p53 binding domain, acidic domain, nuclear localization and nuclear export domains. In general, all 30 novel transcript variants were aberrantly spliced, however, interestingly, 9/23 aberrantly spliced variants in OSCC codes for an in-frame putative protein, suggesting that despite the aberrant splicing, these transcripts may still result in a functional protein and therefore further work to study how these splice variants affect MDM2 function directly or how they may affect other binding partners is needed.

Abstract: The implementation of information technology in healthcare is a significant focus for many nations around the world. However, information technology support for clinical care, research and education in oral medicine is currently poorly developed. This situation hampers our ability to transform oral medicine into a �learning healthcare discipline� in which the divide between clinical practice and research is diminished and, ultimately, eliminated. This paper reviews the needs of and requirements for information technology support of oral medicine and proposes an agenda designed to meet those needs. For oral medicine, this agenda includes analyzing and reviewing current clinical and documentation practices, working toward progressively standardizing clinical data, and helping define requirements for oral medicine systems. IT professionals can contribute by conducting baseline studies about the use of electronic systems, helping develop controlled vocabularies and ontologies, and designing, implementing, and evaluating novel systems centered on the needs of clinicians, researchers and educators. Successfully advancing IT support for oral medicine will require close coordination and collaboration among oral medicine professionals, information technology professionals, system vendors, and funding agencies. If current barriers and obstacles are overcome, practice and research in oral medicine stand ready to derive significant benefits from the application of information technology.

Abstract: Lately, several new stem cell sources and their effective isolation have been reported that claim to have potential for therapeutic applications. However, it is not yet clear which type of stem cell sources are most potent and best for targeted therapy. Lack of understanding of nature of these cells and their lineage-specific propensity might hinder their full potential. Therefore, understanding the gene expression profile that indicates their lineage-specific proclivity is fundamental to the development of successful cell-based therapies.

Abstract: Dear Editor, We thank Rentoft and colleagues for commenting on our paper �Transcriptional profiling of oral squamous cell carcinoma using formalin-fixed paraffin-embedded samples�, and agreeing that formalin-fixed paraffin embedded (FFPE) tissue specimens can be used for gene expression studies using microarrays, to identify genes that are significantly involved in oral carcinogenesis. The similarities and high concordance between the study by Rentoft et al. [1] and ours [2] is comforting and clearly supports the use of FFPE tissues in such experiments. More importantly, these studies act as independent validation for one another and strongly suggests that genes that were found to be up- or down-regulated in oral squamous cell carcinoma (OSCC) do indeed play a role in these cancers and therefore warrant further investigation to determine their utility as biomarkers and therapeutic targets for OSCC. We wanted to point out however, that the similarities between these 2 studies are not completely unexpected despite previous reports highlighting that the concordance between microarray studies are hard to achieve [3]. The main disparities between datasets from microarray experiments have been attributed to the use of different microarray platforms and the heterogeneity of the tissue specimens that were used [4] and [5]. Indeed, many microarray studies reported for the head and neck, used tissues from several distinct areas which have been reported to be genetically heterogeneous, and associated with different aetiologies [6] and [7]. Given that both our studies used the DASL assay and tissues from the oral cavity (albeit from different sites-explained further below) the consistency of the genes that were identified should not come as a complete surprise. However, it is still intriguing that the similarities between these two studies were so close despite previous reports indicating that there are distinct differences between oral cancers associated with different aetiology [8] and [9], and reports describing the distinct genetic differences between subsites of the oral cavity [10], [11] and [12]. Our previous study describing the differences in gene-expression patterns between oral cancers associated with betel quid chewing and smoking demonstrated that despite the differences seen, genetic changes common to all the cancers were also observed suggesting that there are core events and pathways that are important regardless of the aetiology or site of the cancer [8]. Consistently, upon close examination of the genes that are most differentially expressed between our study and that of Rentoft et al. [1] 5 of the top 10 over-lapping genes most differentially expressed were matrix metalloproteinases, whilst other genes include IL-8, CXCL-9 and BCL2A1, genes that were consistently up-regulated in many other microarray studies of the head and neck independent of the subsites of cancer [8], [12], [13] and [14]. An unprecedented large overlap of genes between our study [2] and that of Rentoft and colleagues [1] may also be due to the smaller number of genes on the arrays that were used in these studies (502 genes), and that these genes were pre-selected based on their involvement in cancer development, whereas the majority of previous studies used platforms consisting of larger arrays and hence could capture much more of the heterogeneity typically observed in cancers. More recently, Illumina launched its whole genome DASL assay and it would be interesting to see if the similarities between buccal and tongue cancers still prevails. In conclusion, increasing number studies including the 2 compared here, strongly supports the use of FFPE tissues for gene expression studies using microarrays. The development of new technologies and statistical methods that addresses the challenges associated with using FFPE tissues, combined with the clinical information available with these specimens, will indeed facilitate the identification and discovery of clinically relevant gene signatures and biomarkers and therapeutic targets to improve the management of cancers in general.

Abstract: Despite the advances in cancer treatment, the 5-year survival rate for oral cancer has not changed significantly for the past 40 years and still remains among the worst of all anatomic sites. Gene expression microarrays have been used successfully in the identification of genetic alterations in cancer development, however, these have hitherto been limited by the need for specimens with good quality intact RNA. Here, we demonstrated the use of formalin-fixed paraffin-embedded tissues in microarray experiments to identify genes differentially expressed between cancerous and normal oral tissues. Forty-three tissue samples were macrodissected and gene expression analyses were conducted using the Illumina DASL assay. We report RNA yield of 2.4 and 0.8 microg/mm(3) from tumour and normal tissues, respectively and this correlated directly with the tissue volume used for RNA extraction. Using unsupervised hierarchical clustering, distinct gene expression profiles for tumour and normal samples could be generated, and differentially expressed genes could be identified. The majority of these genes were involved in regulation of apoptosis and cell cycle, metastasis and cell adhesion including BCL2A1, BIRC5, MMP1, MMP9 and ITGB4. Representative genes were further validated in independent samples suggesting that these genes may be directly associated with oral cancer development. The ability to conduct microarrays on formalin-fixed paraffin-embedded specimens represents a significant advancement that could open up avenues for finding genes that could be used as prognostication and predictive tools for cancer.

Abstract: Objectives: To characterize differential gene expression between oral cancerous tissues and the normal mucosal tissues of oral cancer patients and oral mucosal tissues of cancer free patients using second generation sequencing. Methods: Five fresh frozen oral cancer tissue samples from smoking patients, with 2 samples of proximal normal were included in this study. An additional 8 samples consisting of normal oral mucosal tissues from the alveolar mucosa of non-cancer patients who had their wisdom tooth removed where 4 were smokers and another 4 were non-smokers was also included. The tissues and socio-demographic information were obtained from the Malaysian Oral Cancer Data and Tumour Bank System (MOCDTBS) at the Oral Cancer Research and Coordinating Centre (OCRCC). Manual macrodissection was used to obtain >70% tumour or normal epithelial tissue. High quality poly A+ RNA was extracted from the macrodissected tissues and second generation sequencing was done using the Illumina Genome Analyzer. Validation of second generation sequencing was done using commercial and custom microarrays. Results: Among the differentially expressed genes, KRT76 which encodes a filament protein that is responsible for the structural integrity of epithelial cells was the most down-regulated gene when comparing all tumours to all normals (excluding proximal normals). KRT76 is the second most down-regulated gene when comparing differential expression between proximal normal and normal non-cancer samples. Further comparison of all tumors against all normals, including the proximal normals, still indicates down-regulation of KRT76, but to a much lesser degree. A similar pattern was also observed for other down-regulated genes such as the KRT2, KRT3, ANKS1B, CPLX2, FGB, HIST1H3A, HIST1H3G, HIST1H4I, LOR and ZFHX2.Conclusions: This pattern of partial cancerisation of proximal normal samples issuggestive of the possible presence of _field cancerisation�.Relevance: The ��field cancerisation�� theory was postulated by Slaughter whereby the occurrence of multiple independent primary tumours was explained by the fact that the upper aerodigestive tract is chronically exposed to carcinogens. Various conventional molecular methods including microarray based technologies have been applied. Nevertheless, there have been no reports utilizing second generation sequencing to elucidate differentially expressed genes in relation to _field cancerisation� in oral carcinogenesis. Using second generation sequencing to discover genes involved in _field cancerisation� may be useful in predicting the outcome of different management strategies for oral cancer patients.

Abstract: Objectives: This study was done to investigate the role of single nucleotide polymorphisms(SNPs) within genes of phase I (CYP1A1) and phase II (GSTM1, GSTT1,GSTP1) of the xenobiotic metabolism and its association with oral cancer risk.Methods: An unmatched case-control study was conducted using 207 newly diagnosed oral cancer patients and 117 non-cancer subjects selected from the OCRCC database. Peripheral blood was obtained from consented individuals and the CYP1A1, GSTM1, GSTT1 and GSTP1 genotypes were determined using polymerase chain reaction (PCR) and restriction enzyme digestion (RFLP). Simple and multiple logistic regression yielding odds ratio (OR and aOR) were employed to measure the association between genetic polymorphisms and risk of oral cancer. Results: In comparing cases and controls for CYP1A1, GSTM1 and GSTT1 polymorphism, the OR was 0.84 (95% CI 0.534 - 1.330), 0.99 (95% CI 0.627 - 1.554) and 0.87 (95% CI 0.541 - 1.388) respectively. However, the adjusted OR for GSTP1 polymorphism, as compared to the wild-type, was 0.43 (95% CI 0.221 - 0.837). It was noted that polymorphism of GSTP1 conferred a 57% reduction in risk of oral cancer as compared to individuals with the GSTP1 wild type genotype. Meanwhile individuals with combination of betel quid chewing habit and/or GSTP1 polymorphism has 1.6 times the risk of oral cancer although it was not statistically significant (95% CI 0.974 - 2.635). Conclusions: Analysis suggested that polymorphism of GSTP1 seems to have protective effect on the risk of oral cancer

Abstract: Oral squamous cell carcinoma (OSCC) is a world health problem and is associated with exposure to different risk factors. In the west, smoking and alcohol consumption are considered to be the main risk factors whilst in India and southeast Asia, betel quid (BQ) chewing is predominant. In this study, we compared the gene expression patterns of oral cancers associated with BQ chewing to those caused by smoking using Affymetrix microarrays. We found that 281 genes were differentially expressed between OSCC and normal oral mucosa regardless of aetiological factors including MMP1, PLAU, MAGE-D4, GNA12, IFITM3 and NMU. Further, we identified 168 genes that were differentially expressed between the BQ and smoking groups including CXCL-9, TMPRSS2, CA12 and RNF24. The expression of these genes was validated using qPCR using independent tissue samples. The results demonstrate that whilst common genes/pathways contribute to the development of oral cancer, there are also other gene expression changes that are specific to certain risk factors. The findings suggest that different carcinogens activate or inhibit specific pathways during cancer development and progression. These unique gene expression profiles should be taken into consideration when developing biomarkers for future use in prognostic or therapeutic applications.

Abstract: A matched case-control, hospital-based study of oral cancer was conducted in Jakarta population. The sample included 81 cases and 162 controls. The purpose of this study was to determine the association between dietary pattern and oral cancer in a Jakarta population using factor analysis. Dietary data were collected using food frequency questionnaire and factor analysis was performed on 15 food groups resulting in four principle factors/components being retained. The first factor "preferred" was characterized by fast food, fermented food, canned food, snacks high in fat and sugar, cooked and raw vegetables, and seafood. The second factor labeled "combination" was loaded by the intake of dairy product, red meat, white meat and fruits. The third factor labeled "chemical related was loaded by processed food and monosodium glutamate and the fourth principle component consisted of drinks and grain was labeled as "traditional". The conditional logistic regression was done using STATA 8 to obtain the odds ratio (OR) of highest tertile of each component retained from factor analysis and the ORs were then adjusted with risk habits. The consumption the highest tertile of the "preferred" pattern increased the risk of oral cancer by two-times compared to the lowest tertile of consumption [adjusted odds ratio (aOR)=2.17; 95% confidence interval (CI)=1.05-4.50]. The chemical related" pattern showed higher risk of about threefold (aOR=2.56; 95% CI=1.18-5.54), while the "traditional" pattern showed an increased of risk by twofold (aOR=2.04; 95% CI=1.01-4.41). In contrast, the "combination" pattern displayed protective effects in relation to oral cancer (aOR=0.50; 95% CI=0.24-1.00). This finding suggests that factor analysis may be useful to determine the diet pattern of a big set of food type and establish the correlation with oral cancer.

Abstract: Altered expression of xenobiotic enzymes such as CYP1A1, GSTM1 and GSTT1 has been reported in some malignant tumors including oral cancer. However, the correlation between these enzymes and clinicopathologic parameters has not been well documented. The aim of this study was to investigate the associations between CYP1A1, GSTM1 and GSTT1 polymorphisms with patients� status at 2-year, age of onset, nodal status, tumor size and disease stage. A total of 195 oral cancer patients were included in this study. Peripheral blood was obtained from consented individuals and CYP1A1, GSTM1 and GSTT1 genotypes were determined using PCR and restriction enzyme digestion. Chi-square test and simple logistic regression yielding odds ratio (OR) was employed for comparison of all parameters except for age of onset where t-test was used. Patients with GSTM1/GSTT1 polymorphism were associated with almost triple increased risk of mortality at 2-year after the first being diagnosed (OR 2.79, 95% CI 1.22�6.36). Mean age of onset was higher in those with GSTT1 null (60.82 ± 10.61 years) and GSTM1/GSTT1 polymorphism genotype (59.48 ± 11.30 years) compared to lower mean age of onset for those with GSTT1 non-null (58.15 ± 11.97 years) and GSTM1/GSTT1 wild-type genotype and these observations were not significant. There was also no significant difference between CYP1A1 and GSTM1 polymorphisms and age of onset. Positive nodes are associated with high CYP1A1 polymorphism, GSTM1 null and GSTM1/GSTT1 polymorphism (59.7%, 56.5% and 72.6%, respectively) and low GSTT1 null (29.0%). For tumor size of more than 2 cm, there was higher percentage of GSTT1 null genotype (92.7%) as compared to those with tumor size of less than 2 cm (p = 0.035). Polymorphisms of all three genes were higher in late stage compared to early stage disease. However, statistically, these observations were not significant. In conclusion, no association was observed between CYP1A1 and GSTM1 polymorphisms and all clinicopathologic parameters studied. This study also showed that for GSTM1/GSTT1 and GSTT1 polymorphisms, association was seen with patients� status at 2-year and tumor size respectively, indicating that the GST genotypes may be important indicators for the patients� status and tumor size in oral cancer.

Abstract: Purpose: to investigate genetic polymorphisms in GSTM1, GSTT1 and CYP1A1 and the association with the risk of oral cancer in the Jakarta population. Method: A total of 81 cases and 162 controls matched for age and sex were selected from 5 hospitals in Jakarta. Sociodemographic data using questionnaires were obtained and peripheral blood samples were collected with informed consent for PCR-RFLP assay. Conditional logistic regression analysis was performed to obtain the association between the risk of oral cancer and GSTM1, GSTT1 and CYP1A1 polymorphisms. Results: GSTM1 and GSTT1 null were slightly overrepresented among cases (60.5% and 45.7% respectively) compared to controls (55.6% and 41.4% respectively), but no statistically significant differences were observed. In contrast, the distribution of CYP1A1 polymorphism was higher among controls compared to cases (52.5 % versus 42.4 %). The odds ratio of null GSTM1 and GSTT1 genotypes was slightly higher compared to wild type genotypes (OR 1.19, 95% CI 0.70-2.02 and OR 1.19, 95% CI 0.72-2.05 respectively). Furthermore, the presence of CYP1A1 polymorphism did not increase the risk of oral cancer (OR 0.70, 95% 0.39-1.25). Conclusion: Genetic polymorphisms of GSTM1, GSTT1 and CYP1A1 may not be risk factors for oral cancer in the Jakarta population.

Abstract: The MDM2 SNP309 has been associated with increased expression of the protein which could suppress p53 function, and has been shown to modulate risk to cancer. We have previously shown that overexpression of MDM2 is a common event in oral cancers. In the present study, we determined the association between the MDM2 SNP309 polymorphism and oral cancer in 207 oral cancer patients and 116 normal subjects. We genotyped the MDM2 SNP309 by PCR-RFLP. Logistic regression was adapted to calculate odds ratios for MDM2 SNP309 polymorphism from univariate and multivariable adjusted models. Our results suggest that MDM2 SNP309 does not confer increased risk to oral cancer (OR=1.55, 95% CI=0.77-3.11). However, the GG/TG genotype was associated with later disease onset in women above 55 years of age. Collectively, our data suggests that MDM2 SNP309 may modulate the risk to oral cancer and is a modifier of the age at oral cancer onset in women above the age of 55 years.

Abstract: The rising burden of cancer in the developing world calls for a re-evaluation of the treatment strategies employed to improve patient management, early detection and understanding of the disease. There is thus an increasing demand for interdisciplinary research that integrates two or more disciplines of what may seemed to be highly unrelated and yet very much needed as strategies for success in research. This paper presents the processes and barriers faced in building partnerships in oral cancer research in a developing country.

Abstract: Metastatic lesions to the oro-facial region may be the first evidence of dissemination of an unknown tumour from its primary site. Case presentation: We described a case of metastatic follicular thyroid carcinoma to the mandible presenting with pain and loosening of teeth in a 70 years old female patient leading to extraction of the loose teeth. Conclusion: The present case emphasizes the importance of considering metastasis in the differential diagnosis of swelling related to loosening of teeth, even though the patient had no history of any malignant disease.

Abstract: Progressive replacement resorption following delayed replantation of avulsed teeth has proved to be an intractable clinical problem. A wide variety of therapeutic approaches have failed to result in the predictable arrest of resorption, with a good long-term prognosis for tooth survival. Bisphosphonates are used in the medical management of a range of bone disorders and topically applied bisphosphonate has been reported to inhibit root resorption in dogs. This study evaluated the effectiveness of a bisphosphonate (etidronate disodium) as an intracanal medicament in the root canals of avulsed monkey teeth, placed before replantation after 1 h of extraoral dry storage. Incisors of six Macaca fascicularis monkeys were extracted and stored dry for 1 h. Teeth were then replanted after canal contamination with dental plaque (negative control) or after root canal debridement and placement of etidronate sealed in the canal space. A positive control of calcium hydroxide placed 8-9 days after replantation was also included. All monkeys were sacrificed 8 weeks later and block sections were prepared for histomorphometric assessment of root resorption and periodontal ligament status. Untreated teeth showed the greatest extent of root resorption (46% of the root surface), which was predominantly inflammatory in nature. Calcium hydroxide treated teeth showed the lowest overall level of resorption (<30% of the root surface), while the bisphosphonate-treated group was intermediate (39%). Ankylosis, defined as the extent of the root surface demonstrating direct bony union to both intact and resorbed root surface, was the lowest in the untreated control group (15% of the root surface), intermediate in the calcium hydroxide group (27%) and the highest in the bisphosphonate group (41%). Bony attachment to the tooth root was divided approximately equally between attachment to intact cementum and to previously resorbed dentin. Overall, bisphosphonate resulted in a worse outcome than calcium hydroxide in terms of both root resorption and ankylosis.

Abstract: Background: Application of PCR techniques requiring only minute amounts of Genomic DNA. Thus, a less invasive, simpler to perform, and cheaper method to obtain DNA from exfoliated cells is desirable. We aim to develop a method that can obtain high quality of genomic DNA from one sample that allows for numerous application of PCR analysis. Objective: This study describes a simple, inexpensive and non invasive protocol to isolate a high quality of genomic DNA from exfoliated cells by using swish method. Methodology: Twenty two subjects vigorously swished 10 ml of normal saline in their mouth for 60 s and spitted into a collection tube. DNA extraction assay was performed by using saliva DNA isolation kit (Norgen, USA). The washed pellets were suspended in TE buffer and analyzed for the quality and purity of DNA content by using the NanoDrop Spectrophotometer. A ratio of A260/A280 was calculated. The extracted genomic DNA was amplified with primers of p53 intron 6 by using PCR machine. The presence of amplified DNA was then confirmed by electrophoreses analysis, which DNA bands were scanned by Typhoon 9410 variable imager. Results: In this study, the extracted genomic DNA demonstrated an average value of 1.94 O.D. in DNA content purity and 42.9 ��g/��l in DNA yields. The electrophoresis images of the DNA products showed visible and detectable bands of higher molecular weight DNA in all the samples. Conclusion: The results showed that the extracted genomic DNA from the exfoliated cells by applying the swish method, that provides substantially larger amounts and higher molecular weight of DNA for down-stream DNA identification application. In addition, all samples were successfully genotyped by PCR-based assays for p53 gene intron 6 regions, which confirmed that the quality of isolated DNA was reliable in supporting the PCR amplification for the molecular studies. Copyright �© 2009 Published by Elsevier Ltd.

Abstract:

Abstract: We have established 3 cell lines ORL-48, -115 and -136 from surgically resected specimens obtained from untreated primary human oral squamous cell carcinomas of the oral cavity. The in vitro growth characteristics, epithelial origin, in vitro anchorage independency, human papilloma-virus (HPV) infection, microsatellite instability status, karyotype and the status of various cell cycle regulators and gatekeepers of these cell lines were investigated. All 3 cell lines grew as monolayers with doubling times ranging between 26.4 and 40.8 h and were immortal. Karyotyping confirmed that these cell lines were of human origin with multiple random losses and gains of entire chromosomes and regions of chromosomes. Immunohistochemistry staining of cytokeratins confirmed the epithelial origin of these cell lines, and the low degree of anchorage independency expressed by these cell lines suggests non-transformed phenotypes. Genetic analysis identified mutations in the p53 gene in all cell lines and hypermethylation of p16INK4a in ORL-48 and -136. Analysis of MDM2 and EGFR expression indicated MDM2 overexpression in ORL-48 and EGFR overexpression in ORL-136 in comparison to the protein levels in normal oral keratinocytes. Analysis of the BAT-26 polyadenine repeat sequence and MLH-1 and MSH-2 repair enzymes demonstrated that all 3 cell lines were microsatellite stable. The role of HPV in driving carcinogenesis in these tumours was negated by the absence of HPV. Finally, analysis of the tissues from which these cell lines were derived indicated that the cell lines were genetically representative of the tumours, and, therefore, are useful tools in the understanding of the molecular changes associated with oral cancers.

Abstract: Introduction: Oral cancer is a common disease in Asia. However, our ability to deliver effective and targeted therapy remains limited by our lack of understanding of the molecular pathogenesis of oral carcinogenesis. One method to understand the nature of genes and gene products whose aberrant expression promote malignant transformation is by using microarrays. However, such studies have been limited by the availability of specimens with intact RNA and adequate clinical data to enable the identi�cation and validation biomarkers either as predictive or therapeutic tools. Objective: We have determined the global gene expression pro�les of oral squamous cell carcinoma (OSCC) of the buccal mucosa using formalin �xed paraf�n-embedded specimens. Materials and Methods: Gene expression analyses using the DASL Assay were performed on 34 paraf�n embedded tissues, of which 22 samples were OSCC of the buccal mucosa and 12 samples were normal surface epithelium of reactive lesions such as the �broepithelial polyp from matched site. We used the Illumina Beadstudio Software to compare the expression pro�les of normal and OSCC samples. We selected genes which were differentially expressed by at least two-fold (with the detection p-value <0.01) for further analysis. Results: A total of 47 genes were differentially expressed by at least two-fold between normal and OSCC. Deregulated genes included genes which were involved in cell signaling, adhesion and invasion, such as ITGB4, MMP1, MMP10, MMP7, CXCL9, and ALOX12. We have validated the over-expression of MMP1, ITGB4 and MMP10, and down-regulation of ALOX12 by quantitative real-time PCR. Conclusion: We have successfully conducted global gene expression studies using paraf�n-embedded buccal mucosa specimens. This approach has enabled the identi�cation of genes whose expression can help explain the aggressive nature of oral cancers arising from the buccal mucosa.

Abstract: Lichen planus, a chronic autoimmune, mucocutaneous disease affects the oral mucosa (oral lichen planus or OLP) besides the skin, genital mucosa, scalp and nails. An immune mediated pathogenesis is recognized in lichen planus although the exact etiology is unknown. The disease most commonly affects middle-aged females. Oral lichenoid reactions (OLR) which are considered variants of OLP, may be regarded as a disease by itself or as an exacerbation of an existing OLP, by the presence of medication (lichenoid drug reactions) or dental materials (contact hypersensitivity). OLP usually presents as white striations (Wickham's striae), white papules, white plaque, erythema, erosions or blisters. Diagnosis of OLP is established either by clinical examination only or by clinical examination with histopathologic confirmation. Direct immunofluorescence examination is only used as an adjunct to the above method of diagnosis and to rule out specific autoimmune diseases such as pemphigus and pemphigoid. Histopathologic features of OLP and OLR are similar with suggestions of certain discriminatory features by some authors. Topical corticosteroids are the treatment of choice for OLP although several other medications have been studied including retinoids, tacrolimus, cyclosporine and photodynamic therapy. Certain OLP undergo malignant transformation and the exact incidence and mechanisms are still controversial. In this paper, etiopathogenesis, diagnosis, management and malignant transformation of OLP and OLR have been reviewed.

Abstract: Purpose: Human b-Defensin (hBDs) is an epithelial origin, cationic antimicrobial peptides. Their expression is reported in oral mucosa, gingiva and salivary glands. However, their protective role is not well understood. It has been suggested that bacterial and viral infection are an important factors in the process of carcinogenesis. This study investigated the expression of hBD-3 in oral squamous cells carcinoma (OSCC). Methods: 29 OSCC and 23 samples of normal and dysplastic tissues were obtained from Oral Pathology diagnostic laboratory, faculty of Dentistry, UKM and UM. The tissues were arrayed and the expression of hBD-3 was analysed using immunohistochemistry technique. Results: Higher levels of hBD-3 expression were found in stage II and II of OSCC compared to stage I and IV. Expression of hBD-3 was also seen higher in the tumour front arrays. Healthy and dysplastic tissues also seen to expressed hBD-3 but most are moderately stained. Conclusion: High levels of hBD-3 expression is seen especially in stage II and III as well as in tumour front suggest a potential tumour marker, correlation between level of expression and probable infective cancer causes need to be investigate further.

Abstract: Purpose: To assess the expression of pRb and EGFR in oral epithelial lesions using TMA technique. Methods: Paraffin embedded specimens were selected from the archives of the Diagnostic Laboratories at the Faculty of Dentistry, University of Malaya and Universiti Kebangsaan Malaysia. Selected epithelial areas were cored and developed into tissue microarray blocks. A total of 32 samples for pRb and 50 samples for EGFR were analysed using immunohistochemical techniques. Results: Abnormal pRb staining (1+ or less) was seen in 80% (8/10) OSCC, 38.5% (5/13) dysplastic and 22.2% (2/9) normal/hyperplastic epithelium. Positive EGFR staining was observed in 25/35 (71.4%) OSCC cases with 11 cases (31.4%) showing staining of 2+ or more. Out of 5 epithelial dysplasia and 10 normal/hyperplastic epithelium, positive EGFR staining was noted in 3 (60%) and 8 (80%) cases respectively. Interestingly, only 1(20%) epithelial dysplasia and 1(10%) normal/hyperplastic epithelium showed staining of 2+ or more. Conclusion: High frequency of abnormal expression of pRb is observed in OSCC cases as compared to dysplastic and normal/hyperplastic epithelium. EGFR is expressed in OSCC as well as epithelial dysplasia and normal/hyperplastic epithelium. However, higher EGFR positivity is more common in OSCC cases. This study supports the feasibility and ease of using TMA technique for immunohistochemical studies.

Abstract: The diagnosis of Darier disease of the oral mucosa was made only after biopsying a leukoplakia-like lesion of the palate.

Abstract: Introduction: Oral cancer is one of the common cancers in Malaysia. Tile population of east coast of Peninsular Malaysia has a different hfestyle and Malay is the predominant race. Oral cancer research in this area started since the Malaysian National Oral Cancer group was established. The aim: of this study is to evaluate the clinical pathological findings and to investigate the role of tobacco smoking, alcohol consurnption and betel quid chewing as tile risk factors among oral cancer cases in east coast of peninsular Malaysia. Materials and Methods: Fifty case records of only treated/operated cases of patients with oral cancer between 1994-2003 in Hospital Universiti Sains Malaysia were reviewed. This study is based on questionnaire developed by the Malaysian National Oral Cancer group. Tile data analysed includes personal reformation and clinical pathological findings. Results: Patients� age range was between 27-97 years old. The male to female ratio was 1.4:1. Malays ethic group has the highest incidence of oral cancer (n=46). Out of 50 cases, 80% were new cases and 66% was squamous cell carcinoma of the oral mucosa. Data revealed 12 different sites of lesions and the highest frequency was on buccal mucosa (30%) with 75% neck node involvement while 12% of the patients have two sites of lesions. Distant metastases occurred in 76.9% of the cases. Tobacco smoking was found to be the predominant risk factor (54%) while 24% of patients were found to be quid chewer. Only 8% of patients consumed alcohol. The remaining14% patients do not admit any of the risk factors and the author would contribute their etiology to viruses. Conclusion: The most common site of oral cancer was buccal mucosa with 75% neck node involvement. Presence of distant metastasis can be witnessed on most cases. More than half cases were new cases. Tobacco smokings exceed betel nut chewing as a probable risk factor among the subjects.

Abstract: Introduction: Alterations in p53, pRb, KI-67 and bcl-2 have been implicated the development of oral cancer although their combined expression in betel quid induced oral mucosal lesions as not clear. The objective of this study is to investigate the expressions of p53, pRb, K1-67 and bcl-2 m oral mucosa of betel quid chewing subjects. Materials and Methods: A total of 64 tissue sections were obtained from biopsy samples of 50 subjects clinically diagnosed with betel chewer's mucosa (BCM, n=32), BCM with leukoplakia (n=12) and leukoplakia (n=6). Oral squamous cell carcinoma (OSCC, 11=10) and normal oral mucosa (n=4) section were used for comparison. Histopathological analysis was made followed by immunohistochemical detection of p53, pRb, Ka-67 and bcl-2, bcl-2 staining was done 111 25 cases of betel chewer's mucosa with~ or without leukoplakia. Results: Histopathologic analysis revealed atypical hyperplastic changes m 46% and dysplasia in 4% of cases. 28% cases showed p53 expression 111 parabasal and superficial layers of epithelium. 14 cases expressed either abnormal pRb or loss of pRb 111 which 8% of cases had cellular atypia and basal cell hyperplasia. 25 cases (50°,0) expressed K1-67 in superficial layers of epithelium indicating high proliferative activity. 36% (9/25) of cases analysed for bcl-2 showed positivity in basal layers of epithelial. Interestingly, 40% (10/16) cases which were bcl-2 negative had high KI-67 expression. Conclusion: The findings of our study suggest that alterations of p53, pRb, Ka-67 and bcl-2 occur early in oral mucosal lesions of betel quad chewing patients. This may aid in early diagnosis of potentially malignant oral lesions and oral cancer developing 111 the betel quid chewing patients who have neither developed chemically recognizable precursor lesions nor exhibit classical dysplastic changes.

Abstract: Introduction: Human telomerase reverse transcriptase (hTERT) the catalytic subunit of telomerase is associated with cellular immortalization and tumorigenesis .In situ detection of hTERT using immunohistochemistry (IHC) allows localizing the hTERT- positive cells and also overcomes the limitation of requirement of fresh tissues for molecular techniques such as Telomeric Repeat Amplification Protocol (TRAP) for telomerase/ hTERT detection. The objectives of this study are to detect hTERT protein expression using immunohistochemistry in different histological stages in oral carcinogenesis with paraffin embedded tissue samples and cultured cells and to relate the hTERT expression with different histological stages in oral carcinogenesis. Materials and Methods: A total of 41 parafin-embedded tissue samples with histological diagnoses of normal oral mucosa (n=5), epithelial hyperplasia (n=5), mild epithelial dysplasia (n=9), moderate and severe epithelial dysplasia (n=8) and oral squamous cell carcinoma (OSCC, n=14) were analysed for hTERT protein using IHC. TRAP assays were performed on cultured cells namely fibroblasts (immortalized with hTERT) and keratinocytes (OSC-20, OSCC cell line, H S R R B, Japan) as positive controls. The hTERT- labelling index was determined following previously published criteria. Results: All the tissues showed Grades 3 & 4 staining (>10% positive staining nuclei) in basal and parabasal cell layers which are the normal proliferative progenitor compartments where hTERT expression is considered normal. hTERT expression in the superficial layers of the epithelia was elevated in moderate and severe dysplasia (75%) with Grades 3 & 4 staining, reduced in mild dysplasia (33.3%) and with no expression in epithelial hyperplasia and normal oral mucosa. hTERT protein expression correlated with positive telomerase activity in the cultured cells. Conclusion: There seems to be an up-regulation of hTERT expression with the progression of oral cancer and therefore indicates the feasibility of IHC detection of hTERT protein as a potential prognostic marker in oral carcinogenesis.

Abstract: Introduction: Uncoordinated data collection by different research groups prompted the initiation of Malaysian oral cancer Research Initiative (MOCRI) group. Objectives: To coordinate and standardize data and tissue collection and storage, develop a minimum dataset on risk factors, intervention techniques and quality of life of oral cancer patients. Materials and Methods: A computer software programme is currently being developed to accommodate multi-centre data collection and research activities in eight hospitals. The complete dataset includes parameters on sociodemographic, clinical, pathological, quality of life measures, details of treatment methods, vital status and dietary intake. Tissues are being collected, stored and catalogued as fresh and formalin-fixed tissues for future use in satellite researches. The networking in tissue and data collection includes the establishment of oral cancer cell-lines. These tissues are being planned for studies on genetic profile, genetic polymorphism, diagnostic and prognostic markers. Results: Tissues and data on 115 oral cancers, 9 leukoplakia and 13 lichen planus has been collected since 2003. Preliminary data from 2004 were analysed for 58 cancer patients. Majority of them are more than 60 years old (65.5%) with a mean age of 63.3. Twenty-four (41.4%) were males, 34 (58.6%) females with the majority of them being Indians (56.9%) followed by Chinese and Malays (15.5% each), Indigenous people of Sabah and Sarawak (12.1%). Eighteen (31%) respondents were smokers, 17 (29.3%) alcohol drinkers and 31 (53.4%) betel quid chewers. Five patients have had histories of family cancers where 3 included immediate family members with head and neck cancers. For the quality of life measure, only 30.2% felt that their daily activities were disrupted despite having advanced cancers. Satellite researches are in progress on genetic polymorphism and tumour markers. One oral cancer cell-line has been established. Conclusion: The establishment of oral cancer database and tissue bank in encouraging and supports on-going satellite researches.

Abstract: Introduction: the tumour invasive front of squamous cell carcinoma (OSCC) has long been recognized as an important area which harbour prognostic information. The aim of the present study was to describe the expression of K1-67, MDM2 and Bcl-2 at the tumour invasive front in the buccal mucosa and also to investigate whether there is any association between the expression of K1-67, MDM2 and Bcl-2 with the certain sociodemographic characteristics, clinical and histopathological parameters. Materials and Methods: The sample of this study consisted of 31 biopsy cases of OSCC from the buccal mucosa. Immunohistochemistry was used with specific antibodies to K1-67, MDM2 and Bcl-2. Evaluation of the nuclear immunoreactivity of all K1-67, MDM2 and Bcl-2 was done at the tumour invasive front (3-6 cell layers at the tumour advancing front). Results: The expression of K1-67, MDM2 and Bcl-2 were detected in 90.3% (28), 64.5% (20) and 16.1% (5) of the cases respectively. The distribution of K1-67 and Bcl-2 immunoreactivity was observed to be quite similar where immunoreactivity was mainly at peripheral invading margin of tumour cell islands with decreasing immunoreactivity towards the centre. The distribution of MDM2 immunoreactivity was unlike that K1-67 and Bcl-2 where the immunoreactivity was observed mainly at the suprabasal region. The present study found significant association between MDM2 expression with gender and Broder�s tumour grading. Significant association was also observed between combined K1-67/MDM2 expression with both gender and Broder�s tumour grading. Conclusion: The present study appeared to suggest no significant association between K1-67, MDM2 and Bcl-2 at the tumour invasive front. No association was also found between k1-67 expression as a proliferative marker and both MDM2 and Bcl-2 as apoptotic markers. However, it appeared to support the observation from the previous study that an increase carcinoma proliferation rate would also be accompanied by an increase in apoptosis.

Abstract: Human telomerase reverse transcriptase (hTERT), the catalytic subunit of telomerase, is strongly associated with telomerase activity implicated in cellular immortalization and tumorigenesis. In situ detection of hTERT will aid in determining the localization of telomerase positive cells. The aim of this study was to detect hTERT protein expression in multistep oral carcinogenesis using paraffin embedded tissue samples, and to study the relationship of hTERT expression with different histological stages in oral carcinogenesis. Normal (n = 4), hyperplastic (n = 4), dysplastic (n = 4) and neoplastic (n = 10) oral epithelia representing different histological stages in oral carcinogenesis were included in the study. hTERT protein detection was done by immunohistochemistry (IHC) technique. Nuclear staining intensities were noted and the hTERT-labelling index was determined. Dysplastic and neoplastic oral epithelia showed an increased percentage of hTERT positive cells (Grade 4: > 50% positive staining nuclei) with intense staining in the basal, parabasal and superficial layers of the epithelia, unlike normal oral mucosa which showed intense staining only in the basal and parabasal cell layers, which are the normal proliferative progenitor compartments. hTERT protein expression was elevated with the corresponding advancement of the histological stages of oral carcinogenesis, from normal to hyperplasia to dysplasia to carcinoma. There seems to be an upregulation of hTERT protein expression during the progression of oral cancer, therefore, this may indicate the feasibility of IHC detection of hTERT protein in oral carcinogenesis as a potential diagnostic or prognostic marker.

Abstract: Some oral verrucal lesions may constitute parts of the clinicopathological spectrum of proliferative verrucous leukoplakia (PVL). Because of its idiopathic yet sinister nature, it is possible that PVL may exist in other populations. The aim of this study was to review the clinicopathological features of persistent, multifocal, oral verrucal lesions in Malaysian population. Methods: Patients with multifocal oral verrucal lesions were selected from surgical and histopathological records. Results: Nine patients of diverse ethnicity with 43 biopsies were reviewed. The mean age at the presentation was 62 years. The most frequent sites affected were gum, sulci, cheek and tongue. Indulgence in risk habits was reported in about 70% of patients. Four cases developed multifocal carcinoma from multifocal leukoplakia. Conclusions: In retrospect, none of the cases fulfilled the original PVL criteria, although three cases were suggestive of PVL. Nevertheless, these findings do not necessarily preclude the existence of PVL as a clinicopathological entity in Malaysian population.

Abstract: Some oral verruco-papillary lesions (VPL) may constitute part of the clinicopathological spectrum of proliferative verrucous leukoplakia (PVL), an aggressive form of leukoplakia. Previous studies in PVL have documented its existence in Western populations but no data exist from the South-East Asia region. Aim: To review the clinicopathological features of persistent, multifocal oral VPL in a Malaysian population. Method: Patients with multiple biopsies of oral VPL were selected from histopathological records. Seven women and three men with diverse ethnic backgrounds were identified. New sections were made and re-examined by a single pathologist. Results: A total of 45 biopsies were reviewed. The mean age at first presentation was 62 years. In 70% of cases, lesions occurred in multiple sites synchronously. The most frequent sites affected were the mandibular gum/vestibule, buccal mucosa and the tongue. Indulgence in risk habits was an over-riding factor in 70% of patients. Surgery was the predominant mode of treatment and recurrences frequently occurred. With hindsight, four cases in this series were diagnosed as PVL. Conclusions: These findings support the existence of PVL as a clinicopathological entity in a Malaysian population. The diagnosis of PVL and institution of early aggressive treatment should be considered when oral VPL are encountered.

Abstract: Aim: A pilot study was carried out in the state of Kelantan, north-east of Malaysia, to determine the feasibility of using pathological and hospital databases to acquire incidence on oral cancer. Method: Data on OC patients (ICD-10: C00.3-00.5, C02-06) were obtained from incident surgical biopsy records of the two main referral centres for head and neck surgery in Kelantan namely, the Department of Pathology, Faculty of Medicine, University of Science and the Oral Surgery clinic, Kota Baru Hospital between January 1994 to December 1998. The crude and age-specific incidence rates were calculated based on the annual population census of Kelantan and this was standardised to the world population. Results: There were forty-three OC cases during that period. The incidence of OC was 6.1 per million annually (males, 1.4 per million; females, 1.0 per million). The age-standardised incidence was 1.7 per million. The main leading sites of OC were the gum and the buccal mucosa/vestibule/retromolar areas. Conclusion: Pathological and hospital records provide an alternative way of obtaining important epidemiological data on OC, crucially in places where population-based cancer registries have not been established.

Abstract: This is an update on cultural and dietary risk factors for oral precancer and cancer. It is an overview on ethnic differences (where possible) and socio-cultural risk factors (tobacco/areca nut/betel quid, alcohol use and dietary factors) in relation to oral precancer and cancer. While studies were from Western countries, India and China, this update also attempts to include and highlight some studies conducted in the Asia-Pacific region.

Abstract: One of the objectives of this short communication was to add to the literature on the prevalence of oral recurrent aphthous stomatitis (ORAS). This research is based on a total of 11,697 randomly selected Malaysian subjects with an age range of 25-115 years and a mean age of 44.5 +/- 13.9 years who were examined for oral mucosal lesions (ORAS). The prevalence of ORAS detected during the oral examination (average point prevalence) was found to be 0.5% (64 subjects). ORAS formed 5.7% of all lesions detected during the survey. The average point prevalence of ORAS was highest in the indigenous people of Sabah and Sarawak (1.2%), followed by the Chinese (0.7%), the Malays (0.5%) and the Indians (0.1%). This difference was statistically significant (p < 0.001). A review of the English literature on the prevalence of ORAS revealed different prevalence types used by different researchers, namely average point prevalence (APP), self reported life-time prevalence (SLP) and self reported two-year prevalence (STP). The other objective of this paper was to present the different types of prevalence that have been reported in the literature and to discuss the usefulness of such prevalence types in relation to using epidemiology in deriving certain possible etiological associations.

Abstract: The aim of this study was to determine the periodontal status and treatment needs among the Indian estate population. The Community Periodontal Index of Treatment Needs was used to obtained clinical data on 208 Indian subjects residing in three estates in the state of Selangor. The prevalence of periodontal disease among the subjects was 100%. Less than 1% of the subjects had bleeding on probing as the highest CPITN score. About 97% of the subjects showed evidence of periodontal pocket of 4mm or more. Of these, half showed pocketing of 6mm or more. No statistically significant difference (p> 0.05) was observed between males and females in terms of the most severe periodontal conditions encountered. About 2.5, 1.6 and 0.9 sextants were involved with pocketing of 4-5mm, calculus and pocketing of 6mm or more respectively. Again this pattern of sextants involvement shows no significant difference by gender (p>0.05%). All subjects required oral hygiene instruction and 97.4% required scaling. Complex periodontal care was required by 48.7% of the subjects. The findings of this study indicate an urgent need for an oral health promotion programme to be instituted aimed at the prevention of periodontal disease and the utilization of appropriate manpower for the control and management of the existing disease in the Indian estate population.

Abstract: A retrospective study of 11 cases of traumatic granulomas was done. The objective of this study is to present the clinicopathological features of traumatic granulomas in some malaysian patients and to compare this data with data from other reported studies, which have been predominantly from Caucasian population. Biopsy records from 1985 to 1998 of 18 cases of traumatic granulomas were obtained. There were 13 male and 5 female patients. The granulomas occured in 38.9% Malay, 38.9% Chinese, 11.1% Indian and 11.1% other ethnic groups. The age of these patients range from 8 to 86 years, with mean of 41.9 �± 17.7 years. The most common location for the lesions was the tongue, other locations were on the floor of mouth-tongue junction, retromolar region, buccal gingiva, lower lip, and anterior mandible with one case presenting with multiple ulcers in different locations. The provisional diagnoses given by the clinicians prior to biopsy include traumatic ulcer, squamous cell carcinoma, lichen planus, recurrent apthous ulcer, Wegenerâ��s granulomatosis, pyogenic granuloma, infectious ulcer (tuberculosis) and squamous cell papilloma. Some of the patients (66.7%) have past/current medical condition, which include diseases of the endocrine, gastrointestinal, cardiovascular system, malignancy, venereal disease, autoimmune disease, and one Human Immunodeficiency Virus positive patient. Histologically, pseudoinvasion of plasma cells and histiocytes between muscle bundles are evident in all cases. Eosinophils are consistently found in all but one case. In conclusion, most of the clinical and histological features present in these cases are comparable to cases in Caucasian reported in the literature.

Abstract: This survey was undertaken to study the clinical features of trigeminal neuralgia in an Asian population. Demographic data of 44 patients treated at the Dental Faculty of the National University of Singapore and at the University of Malaya were reviewed. The results of the survey were analysed and comparisons made with those of Caucasian patients as reported in other studies where there was a general similarity in the clinical findings. Trigeminal neuralgia presented predominantly in females. Right-sided involvement occurred at a greater frequency, and the peak age at onset was between the sixth and seventh decades of life. The only significant variant in the present sample was the greater involvement of the mandibular branch of the trigeminal nerve rather than the maxillary division. In addition, there was a much greater representation from Chinese patients over Malays as compared with their ratios in the general population.

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Abstract: The prevalence of oral mucosal lesions in Malaysia was determined by examining a representative sample of 11,707 subjects aged 25 years and above throughout the 14 states over a period of 5 months during 1993/1994. A two-stage stratified random sampling was undertaken. A predetermined number of enumeration blocks, the smallest population unit in the census publication, was selected from each state. With the selected enumeration block, a systematic sample of living quarters was chosen with a random start. The survey instrument included a questionnaire on sociodemographic characteristics and a clinical examination. The clinical examination was carried out by 16 specially trained dental public health officers and the diagnosis calibrated with a final concordance rate of 92%. The age in the sample ranged from 25 to 115 years with a mean of 44.5+/-14.0. The sample comprised 40.2% males and 59.8% females; 55.8% were Malays, 29.4% Chinese, 10.0% Indians and 1.2% other ethnic groups. Oral mucosal lesions were detected in 1131 (9.7%) subjects, 5 (0.04%) had oral cancer, 165 (1.4%) had lesions or conditions that may be precancerous (leukoplakia, erythroplakia, submucous fibrosis and lichen planus) and 187 (1.6%) had betel chewer's mucosa. The prevalence of oral precancer was highest amongst Indians (4.0%) and other Bumiputras (the indigenous people of Sabah and Sarawak) (2.5%) while the lowest prevalence was amongst the Chinese (0.5%).

Abstract: A house to house survey on elderly subjects aged 60 years old and above was undertaken in a large district in Malaysia. A total of 486 subjects in randomly selected Enumeration Blocks were interviewed and examined. The prevalence of oral precancerous lesions was recorded at 3.3%, of which leukoplakia was the most common. When the ethnic distribution of these oral precancerous and cancerous (OPC) lesions was compared, 72% of those inflicted were Indians. Oral cancer was detected in two subjects (0.4%), both of whom were of Indian origin. Among subjects with OPC lesions, 4.2% were smokers, 12.7% were betelquid chewers, 11.8% had indulged in both habits, whilst one subject had not practised any of the oral habits of interest (0.4%). The findings suggest the occurrence of OPC lesions to be related to betelquid chewing.

Abstract: The immunohistochemical expression of proliferating cell nuclear antigen (PCNA) and p53 was investigated in 9 cases of epithelial dysplasia and 38 cases of squamous cell carcinoma of the oral cavity. The intensity of immunoreactivity for each marker was assessed using a semiquantitative grading system, and was correlated with tumor differentiation, nuclear atypia and the patterns of invasive margins in the underlying connective tissue. PCNA expression, in dysplastic epithelium, was observed in the suprabasal and lower spinous layers; and the labeling grade and intensity of staining increased along with the degree of cellular atypia. In 2 cases of dysplasia, weak positive immunoreactivity for p53 could be seen in a few isolated cells of the basal layer. In squamous cell carcinoma, PCNA expression was correlated with the degree of tumor differentiation and nuclear atypia in well and moderately differentiated carcinoma, but not with the invasive pattern of tumor growth. Immunoreactivity for p53 was positive in 30 cases and showed a distribution pattern very similar to PCNA but with fewer positive cells. Three distinct categories of expression for PCNA and p53 were observed, among them a combination of intense reactivity for both markers was indicative of poor differentiation, higher nuclear atypia and more invasive growth of tumor cells.

Abstract: Ensuring the validity and reliability of data collected in epidemiological surveys is an important consideration. The purpose of the present report is to describe a training and calibration programme for 16 examiners taking part in a national survey of oral mucosal lesions and to present an evaluation of the results. The programme included the distribution of a pictorial manual to participants and a series of lectures followed by three diagnostic sessions, two using slides and the last involving patients. At the final session, the trainees classified 88 per cent of 16 patients correctly in comparison with the definitive diagnoses of the trainer, and their sensitivity on recording oral carcinoma, leukoplakia and lichen planus was at least 0.88. However, correctly classifying submucous fibrosis on the basis of slides alone proved problematic. At the conclusion, the diagnostic accuracy of two examiners for all types of lesion remained appreciably lower than the majority. Training strategies for various types of study are discussed. The method reported is considered to represent a model approach to training and calibrating examiners for this type of survey work.

Abstract: This was a retrospective study of dentigerous cysts in people from the Singapore-Malaysian region.The purpose of this study was to present the clinicopathologic features of dentigerous cysts in theOriental population and to compare these data with those from other reported studies. Biopsy recordsfrom 1981 to 1993 of 119 cases of dentigerous cysts from patients in Malaysia and Singaporeshowed that 36.1% of patients were female and 63.9% patients were male. Among patients withcysts, 70.5% were Chinese, 23.2% were Malays, 2.7% were Indian and 3.6% were other ethnicgroups. The mean age of these patients was 30.2 + 17.3 years with a peak incidence occurring inthe second and third decades. The location of the lesions was almost equal to the maxilla (50.9%)and the mandible (49.1%). There was a marked predilection for the posterior mandible (42.7%)followed by the anterior maxilla (38.2%). Histologically, 90.8 % of the cysts were lined by a non-keratinised stratified squamous epithelium. The cyst linings were mainly thin (90.0%) with 38.7%of cases having a mixed thick and thin lining. Mucous metaplasia was observed in 9 (7.6%) cases.Rushton bodies were seen in 3.4% of cases. Cholesterol clefts in the epithelial lining and lumenwere found in 16.8% cases while 12.6% of cases exhibited cholesterol clefts in the cyst wall.Other cellular structures within the cyst wall were lymphocytes (66.4%), plasma cells (52.1%),Russell bodies (16.0%) and histiocytes (4.2%). Odontogenic keratocysts were observed in 5.0%of cases. One case of adenomatoid odontogenic tumour was also observed. Epithelial atypia wasseen in 9.2% of cases, islands of stratified squamous epithelial cells in 8.4% of cases while onecase showed a combination of these two features. In conclusion, some clinical features seen in thisstudy are similar to that for the Caucasian population such as prevalence in male, peak incidence inthe second and third decades and the predilection for the posterior mandible and anterior maxilla.Histopathologically, odontogenic keratocyst and adenomatoid odontogenic tumour were observedin dentigerous cysts.

Abstract: A clinical analysis of 304 cases of pyogenic granuloma (excluding pregnancy tumour) were obtained from the clinical evaluations submitted by clinicians while sending specimens for biopsy. The average age of the patients with pyogenic granuloma was 28.9 years with a peak age incidence in the second decade. More female patients were affected and the lesions present mainly in the Chinese. The majority of the lesions were ulcerated and pedunculated. The lesions had a mean diameter of 10.8 mm with a mean lesion duration of 6.0 months. The gingiva was the prevalent site for these lesions with a greater number being located in the maxilla. The recurrence rate was found to be 14.1%.

Abstract: A case of bullous pemphigoid with extra-oral and intraoral lesions in a 60-year-old female is reported. Diagnosis is based on histopathology and direct immunofluorescence, and the treatment regime described included oral prescription of prednisolone and topical application of a mixture of fluocinonide ointment and triamcinolone acetonide in Orabase on the oral lesions.

Abstract: Peripheral fibroma/fibrous epulis accounts for the great majority of localised gingival swellings as was substantiated by various reports in the literature. A study was undertaken to investigate the clinical features of a series of 204 localised fibrous gingival swellings received by the Histopathology Laboratory, Department of Oral Surgery, National University of Singapore. The female patients were more affected than the male patients and the lesions occurred predominantly among the Chinese. The lesions were mainly pedunculated and most commonly occurred in anterior maxilla. The recurrence rate was about 10.3%. In conclusion the results obtained in this study were overall in agreement with those of other authors.

Abstract: At the Faculties of Dentistry in Chiang Mai, Thailand (CM), and Kuala Lumpur, Malaysia (KL), 234 and 233 consecutive out-patients of mean ages 33.8 and 31.0 yr, respectively, were examined for the presence of oral mucosal lesions. Tobacco in some form was regularly used by 31.7% and 27.5% of the study populations in CM and KL, respectively. Cigarette smoking was the predominant habit. In CM three persons chewed betel quids and nine smoked banana leaf cigars daily. In addition, there were 24 habitual chewers of tea leaves (miang). In KL six persons chewed betel quids daily. In CM and KL three cases each (1.3%) of tobacco-associated leukoplakias were found. In KL an additional idiopathic leukoplakia was registered. One and three cases of betel related lesions were found in CM and KL, respectively. One case of a squamous cell carcinoma was found in a 45-yr-old Indian woman in KL who had been chewing betel with tobacco daily for many years. High prevalence figures were found for lichen planus, 3.8% in CM and 2.1% in KL, and an extremely high one, 48.3%, in CM for episodes of aphthous ulcers experienced during the last 2 yr. Comparatively low prevalence figures were found for herpes labialis. As could be expected melanin pigmentation was prevalent while only low figures were encountered for denture-related lesions and amalgam tattoos.

Abstract: Two hundred four cases of fibrous lesions of the gingiva were studied histologically for the presence of calcified tissue, the nature of the connective tissue, the type of keratinization, and the degree of epithelial thickness. Initially these lesions were subcategorized into four specific entities, namely fibrous epulis, fibroepithelial polyp, calcifying fibroblastic granuloma, and ossifying fibrous epulis. It was found that 46.5% of the lesions contained calcifications. The connective tissue was represented predominantly by either the collagenous type (50.5%) or the mixed (cellular and collagenous) type (44.6%). It was also found that 36% of the lesions were ulcerated, and, of these, 79.5% were associated with the cellular type of connective tissue and calcifications. In an attempt to subcategorize the fibrous lesions into specific entities, it was found that 32 cases (15.7%) had mixed features. This fact supports the suggestion that these lesions are stages in the spectrum of a single disease process and should collectively be termed fibroblastic gingival lesions. However, it is also suggested that the two terms, namely peripheral fibroma and fibrous epulis with and without ossification, should be retained whereas the usage of other terminologies should be avoided.

Abstract: The prevalence of clinically observed oral lichenoid reaction in 186 Malay army personnel using Fansidar for 9 weeks was found to be 4.8%. The prevalence was found to be 0.5% in 186 army personnel who had stopped using Fansidar for 2 months and 0% in 143 army personnel (control group) who had not used Fansidar for at least 4 months. The lesion showed a higher prevalence for the gingiva. There was no correlation between cigarette smoking and the occurrence of these lesions in each group.

Abstract: The aim of this study is to determine the social impact of oral and facial pain in a sample involving an industrial population. Out of a total of 355 subjects interviewed, nearly one-half claimed to have oral and facial pain in the previous one month prior to the survey. The most common type of pain was that related to hot or cold fluids or sweet things followed by toothache. On the average, the pain lasted for 4.2 days (SD = 4.9) per person in the past one-month. About one in five persons with pain reported that it was severe enough to disrupt sleep. About one in ten persons reporting pain had to take sick leave because of the pain. However, only one in four persons with pain consulted a doctor or dentist. More than one-third tried to cope with the pain and did nothing while the rest tried various means of self-cure. It is therefore postulated that in this population, pain per se is a poor predictor of utilisation of dental services. Further research into pain coping behaviour and how this affects of pattern of utilisation of dental services is indicated in order to formulate a strategy to encourage the habit of seeking prompt dental care by the target population.

Abstract: The qualitative and quantitative changes occurring in the taste buds of the fungiform papillae of male Sprague-Dawley rats (aged 51-125 days old) after x-ray irradiation were studied. A single dose of 2000 Roentgen (R) was delivered and observations were made at 0, 3, 7, 14, 21 and 30 days after x-ray irradiation. The changes in taste bud morphology were interpreted first as degenerative and then as regenerative at various stages of the study. The degenerative process appeared at about the third day and reached a peak at 7 days. Regeneration then began after a further week and the taste buds appeared mature at about 30 days. While the number of fungiform papillae remained constant throughout the study, there was a marked loss of taste buds on these papillae at 7 days. At 14 days, the number of taste buds increased from this low level, and by 30 days the number approached the control values. Initial taste bud loss could be attributed to a direct irradiation damage leading to taste bud cell desquamation combined with a concomitant mitotic inhibition of the stratum germinativum.

Abstract: The association between cigarette smoking and the prevalence of oral mucosal lesions was examined in 495 Malaysian army personnel. No associations between cigarette smoking and recurrent aphthous ulcerations, pre-leukoplakia and frictional keratosis could be obtained in this study. Positive associations were found between cigarette smoking and leukoedema as well as denture stomatitis. There was a negative association between cigarette smoking and the presence of coated tongue.

Abstract: A total of 149 periapical lesions were classified histologically into cysts, granulomas and other lesions. It was found that 53% were cysts, 39% were granulomas and 8% were other lesions. Of the 149 periapical lesions classified, 69 selected cases of cysts and granulomas were obtained and radiographic measurements of area (mm2), largest diameter (mm) and largest root-to-border distance (mm) were recorded. It was found that there is an apparent increase in cystic prevalence with an increase in the area, largest diameter or largest length of the periapical lesions radiographically. A cystic prevalence of 92-100% is observed with a radiographic area of greater than 200 mm2, a radiographic distance and diameter of greater than 20 mm.

Abstract: Many studies have been reported on radiographic lesion sizes of periapical lesions. However no studies have been reported on prevalences of subjective radiographic features in these lesions except for the early assumption that a periapical cyst usually exhibit a radiopaque cortex. This study is conducted to evaluate the prevalences of several subjective radiographic features of periapical cysts and granulomas in the hope to identify features that maybe suggestive of either diagnosis. The results showed that a regular (circular or semi-circular) radiographic outline is likely to be a periapical cyst while an irregular radiographic outline is not indicative of either a cyst or a granuloma. The association between the regular/irregular radiographic outline and the type of periapical lesion was found to be statistically significant (p less than 0.001). The associations of two other radiographic features and the type of periapical lesion were found to be just statistically significant (p less than 0.01). These features are the symmetry/asymmetry of the radiolucency in relation to the apex and the funnel-shaped/angular-shaped extension of the radiolucency. The widely accepted criteria that the possession of a radiopaque cortex surrounding the radiolucency can discriminate between a periapical cyst and granuloma cannot be statistically supported in this study.

Abstract: A case of an incomplete tooth fracture followed by a complete fracture was presented. The difficulty of diagnosing this condition was discussed as well as the possible histological explanation of the symptoms experienced by the patient. It once again points out to practising dentists, that whilst deep pockets can give rise to severe periodontal pain, intense and excruciating pain should be investigated with the cracked tooth in mind.

Abstract: A study on the oral health status of 198 factory workers (in Antara Steel, Pasir Gudang, Johor) was carried out in November 1986. The subjects were predominantly male (94%) and Malay (91%) with an average age of 27.4 years. The prevalence of caries was 87.4% with a mean DMFT of 7.1 + 5.4. There were 3 subjects with full upper, lower dentures and 16 subjects with partial dentures. Two subjects examined needed dentures but were not wearing them. Thirty five (17.7%) of those examined needed urgent extractions, and 8 needed emergency treatment for fillings. Enamel opacities were found in 141 subjects (75.6%) but only 9 were aware of these defects. Dental health was very poor with 72% examined needing scaling. Seventeen (9%) had gross supra and subgingival calculus. There was a total of 107 (54%) smokers and heavy nicotine stains were found in 41 (20.7%), of the population examined. Examination of soft tissues showed 111 (56%) subjects with recurrent aphthous ulcers whilst 15 (7.6%) suffered from herpes labialis. Five subjects (2.5%) suffered from denture stomatitis whilst the prevalence of other soft tissue lesions was very low.

Abstract: This is a case report of a reactive lesion which occurs only in the gingiva. This lesion is of a long duration causing erosion of the superficial bone. Histologically it is similar to other epulides of the gingiva but in addition contains ossified tissue. The lesion's confusing terminology is being discussed in view of its understanding to an American-trained or a British-trained surgeon. A review of literature showed a recurrence rate of 7-20% thus making it mandatory for a close follow-up of the patient.

Abstract: This is a case report of an oral lichenoid drug reaction of the buccal sulci in a female diabetic patient who was on an anti-hypertensive drug, alpha-methyldopa (Aldomet) and an oral hypoglycaemic drug, chlorpropamide (Diabinese). The clinical features, histological findings and management are presented.

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Abstract: A study has been conducted on 198 employees of a steel-mill industry. These participants were examined for mucosal lesions in the oral cavity and including the commissures and vermillion borders of the lips. The prevalences of 16 types of lesions are reported.

Abstract: Two case reports of an uncommon type of oral ulcerative lesion are presented. These lesions are of long duration, benign and reactive, and may clinically mimic a malignant ulcer. Histologically, these are deep lesions which exhibit 'pseudoinvasion' into skeletal muscle. There is a predominance of eosinophils while other chronic inflammatory cells such as plasma cells and histiocytes are in abundance. A brief review of the literature showed past treatment being surgical excision, incisional biopsy, radiation, cryosurgery with liquid nitrogen and no treatment. All modalities used result in resolution of the lesion.

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Abstract:

Abstract: 29 patients with buccal carcinoma were reviewed for the clinical signs and symptoms. The TNM classification following the UICC categories were used for the clinical staging of the lesion. The patient�s race, age, sex and habits were also noted. Most of these patients presented with advanced lesions. The most common signs and symptoms were pain and ulcerations (62%). The histopathology of a well-differentiated squamous cell carcinoma forms a great majority of these lesions (62%). Each of the sign and symptom is discussed in relation to other findings that had been reported.

Abstract: Background: There are limited studies on the effects of drugs that modulate epigenetic regulation for head and neck squamous cell carcinoma (HNSCC). This study determined the effect of valproic acid (VPA) on HNSCC. Methods: Growth inhibition effects of VPA alone or in combination with 5-aza-2�deoxycytidine (5-aza-dC) or all-trans retinoic acid (ATRA) was evaluated with MTT and clonogenic assays on 5 HNSCC cell lines. The mechanism of growth inhibition was investigated by looking at markers of terminal differentiation and senescence. Results: Growth inhibition profiles of HNSCC cell lines varied in response to VPA. Inhibition of clonogenic survival in response to VPA was associated with an upregulation of p21, expression of terminal differentiation markers, and cellular senescence. Notably, a combination treatment of 5-Aza-dC-VPA-ATRA enhanced growth inhibition in cells resistant to VPA. Conclusion: VPA is a potent inhibitor of proliferation in some HNSCC cell lines, and may be used to treat HNSCC.