Carlo E. Poggio, DDS, MSD, PhD is owner of Studio Associato Poggio, an interdisciplinary dental practice with more than 50 years of history located in the heart of Milan historical center. He is also a Visiting Professor for Interdisciplinary Treatments at the Postgraduate Program in Orthodontics in the University of Milan and an Adjunct Assistant Professor at the Department of Prosthodontics, University of Rochester (NY). He is a member of the Cochrane Oral Health group (Manchester, UK), as well as fellow of several national and international dental associations. He is a member of the Executive Board of the Italian Academy of Prosthetic Dentistry (AIOP), one of the largest Italian dental societies and a member of the International Relationship Commitee of the American Prosthodontic Society. He has lectured extensively in Italy and abroad on topics related to interdisciplinary treatment planning in dentistry, management of TMD patients, use of dental implants in complex interdisciplinary rehabilitations.
Abstract: Long-term results after orthopedic or surgical treatment of hemifacial microsomia (HFM) have shown a tendency toward recurrence of the facial asymmetry. However, the literature contains a number of successful case reports that show surprising changes in the morphology of the condyles. In addition, patients with similar mandibular asymmetries, treated early with surgery, have excellent long-term follow-ups, especially those who have little or no soft-tissue involvement, but only severe mandibular ramal deformities. The phenotypes of these cases are unexpectedly similar, with a consistent collapse of the condyle against the coronoid and a deep sigmoid notch. The objectives of this article were to help distinguish true HFM from this peculiar type of hemimandibular asymmetry morphologically and to quantify their differences before treatement and in the long term.
Abstract: The literature contains a number of case reports on successful orthopedic treatment of hemifacial microsomia (HFM), with surprising changes in the morphology of the condyles. All of these reports regard patients who have substantially no soft tissue involvement but only severe mandibular ramus and condyle deformities. A number of cases with unexpectedly similar phenotypes diagnosed as HFM are described. The authors suggest that it is possible that all of these cases might be misdiagnosed traumatic injuries of the condyle, which present a normal functional matrix and, therefore, with growth and with the help of functional stimulation, tend to grow toward the original symmetry.
Abstract: The case report of a patient is presented who had been suffering from a plasmacytoma of the spine several years back, and who had developed a new plasmacytoma of the mandible, 3 years subsequent to the insertion of a dental implant. This second solitary lesion occurred 15 years after the first one, and without signs of conversion to multiple myeloma. Research in animal models has shown multinucleated giant cells, belonging to the monocyte-macrophage lineage, persisting between the titanium surface and the lymphohemopoietic compartment, at least 1.5 years after implant insertion. Factors that increase the proliferative activity of precursor B cells, for example a protracted macrophage activation, are likely to increase the risk of B cell oncogenesis. A possible role of the titanium surface in an increase of precursor B cell proliferative activity, thus facilitating a new localization, was evaluated.
Abstract: The aim of this work was to evaluate whether the protrusion of nose and chin influence the perception of the ideal tooth anterior limit line. The orthodontic, or combined orthodontic-surgical diagnosis, and the following treatment plan are in close correlation with a patient's requirements for aesthetic facial balance. This requires consideration of the position of the maxillary incisors which is often modified by treatment; it is obvious how important it is to clarify which are the facial features which determine the aesthetically ideal anteroposterior position of the incisors.
Abstract: Twenty-two implants inserted in the anterior area in 15 patients, and 24 implants inserted in the posterior area in 9 patients, for a total of 46 implants in orthodontic patients suffering from single or multiple agenesis, were analyzed retrospectively. The average time of follow-up, subsequent to the prosthetic insertion was 60.3 months. The average time from actual diagnosis of agenesis to the completion of therapy was 76.2 months. There were no implant failures, although 17.4% experienced prosthetic complications. Analysis of the sample identified 5 critical issues that are frequently underestimated at the time of determining the therapeutic strategy. 1. Timely comprehensive management of the patient; 2. management of the biological interface (surgery and hygiene maintenance); 3. prosthetic problems; 4. long term effects of bone remodeling; 5. alternative therapy.
Abstract: During the early phases of single-implant treatment, clinician needs and patient expectations can be challenging. This article describes a technique for making a simple bonded provisional restoration. In addition to minimizing patient discomfort without increasing laboratory costs, the technique enables soft tissue preservation through all treatment phases, from tooth loss to implant loading.
Abstract: This article describes the correction of an unesthetic implant position that resulted from unexpected postpubertal growth. Surgical implant repositioning, a technique similar to single-tooth osteotomies, was used. The implant and surrounding bone were mobilized, and a green stick fracture was made on the buccal plate. With pivoting on the buccal plate, the implant was moved to a more palatal position and restored. Although some degree of asymmetry could still be detected, a satisfactory esthetic result was achieved.
Abstract: A recently introduced three-dimensional computerized system with landmark representation of the soft-tissue facial surface allows noninvasive and fast quantitative study of facial growth. The aims of the present investigation were (1) to quantify growth changes in soft-tissue facial morphology, (2) to evaluate sex differences in growth patterns, and (3) to provide reference data for selected angular and linear measurements that could be of interest for the objective analysis of maxillofacial surgery or orthodontic patients. The three-dimensional coordinates of 22 standardized facial landmarks were automatically collected by automated infrared photogrammetry using the three-dimensional facial morphometry method in a mixed longitudinal and cross-sectional study, in which 2023 examinations were obtained in 1348 healthy nonpatient subjects between 6 years of age and young adulthood. Selected parameters (angles, linear distances, and ratios) were calculated and averaged for age and sex. Male values were compared with female values by means of Student's t test. Within each age group, linear distances were significantly larger in boys than in girls (p < 0.05) with some exceptions coinciding with the earlier female growth spurt, whereas angular measurements did not show a corresponding sexual dimorphism. Linear distances in girls had almost reached adult dimensions in the 12-to-13-year-old age group, whereas in boys a large increase was still to occur. This was most evident in the middle third of the face, where both sexes showed almost the same dimension and amount of growth up to the age of 13, with significant differences afterward, boys being larger than girls. On the contrary, in the lower third of the face, significant differences occurred throughout the whole investigated period, boys being always larger than girls. The male versus female angular comparison reflected the differential timing in attainment of adult proportions. The three-dimensional facial morphometry method allowed the noninvasive evaluation of a large sample of nonpatient subjects, leading to the definition of three-dimensional normative data about facial soft tissues. The method could supplement more invasive radiographic evaluations, allowing frequent examinations of children and adolescents before and during treatment, as well as in the follow-up.
Abstract: The three-dimensional arrangement of dental cusps and incisal edges in human dentitions has been reported to fit the surface of a sphere (the curve of Monson), with a radius of about 4 inches in adults. The objective of the current study was to compare the three-dimensional curvature of the mandibular dental arch in healthy permanent dentitions of young adults and adolescents. The mandibular casts of 50 adults (aged 19 to 22 years) and 20 adolescents (aged 12 to 14 years) with highly selected sound dentitions that were free from temporomandibular joint problems were obtained. The three coordinates of cusp tips excluding the third molars were digitized with a three-dimensional digitizer, and used to derive a spherical model of the curvature of the occlusal surfaces. From the best interpolating sphere, the radii of the left and right curves of Spee (quasi-sagittal plane) and of molar curve of Wilson (frontal plane) were computed. Mandibular arch size (interdental distances) was also calculated. The occlusal curvature of the mandibular arch was not significantly influenced by sex, although a significant effect of age was found (Student t, P <.005). The radii of the overall sphere, right and left curves of Spee, and curve of Wilson in the molar area were about 101 mm in adults, and about 80 mm in adolescents. Arch size was not influenced by either sex or age. The different curvatures of the occlusal plane in adolescents and adults may be explained by a progressive rotation of the major axis of the teeth moving the occlusal plane toward a more buccal position. These dental movements should be performed in a frontal plane on an anteroposterior axis located next to the dental crown.
Abstract: To describe normal soft tissue growth and development of the human face through volume changes and to assess the presence of sexual dimorphism.
Abstract: In this investigation, the precision of a commercial three-dimensional digitizer in the detection of facial landmarks in human adults was assessed.
Abstract: Normal facial growth and development was analyzed through indirect anthropometry in a mixed longitudinal and cross-sectional investigation; 2,023 examinations were performed on 1,156 healthy Caucasian children and adolescents between 6 and 17 years of age and on 191 young adults. Three-dimensional coordinates of 22 facial landmarks were collected with the Three-Dimensional Facial Morphometry method by automated infrared photogrammetry. Selected three-dimensional parameters (linear distances, angles, and a ratio), describing facial height, width, depth, and convexity on the horizontal plane, were calculated and averaged for age and sex. Within each age group, most linear distances were significantly larger in males than in females, with some exceptions in the 11 to 12 age group, where female growth velocity showed a spurt. In females of the 14 to 15 age group the face had almost completed growth; in males of the same age group, a large increase was still to occur to attain adult values. The sexual dimorphism of the parameters calculated did not appear in the different parts of the face to the same extent: a large part of male facial preponderance occurred in the lower third of face. From 6 years of age to adulthood, the soft-tissues in the facial lower third increased by about 23% (males) and 17% (females), in the middle third by about 18% (males) and 13% (females), and in the upper third by about 16% (males) and 9% (females). The male vs. female comparisons within each age group suggested a sexual dimorphism in the timing of soft-tissue facial growth, but an overall similar attainment of different adult dimensions.
Abstract: The object of this investigation was to determine whether children of the same age with different headforms differ in their three-dimensional soft-tissue facial characteristics. The three-dimensional coordinates of 22 standardized facial landmarks were automatically collected in a sample of 70 boys and 71 girls age 11 to 13 years attending a junior high school. From the collected landmarks, several three-dimensional facial angles, linear distances, linear distance ratios, and volumes were calculated. For each subject the cephalic index (maximal head breadth/ maximal head length x 100) was computed and three groups of measurements for each sex were obtained (dolicho-, meso- and brachycephalic). A two-way factorial analysis of variance compared the effects of sex and headform, and the interaction sex x headform. On average, boys had significantly (P < or = 0.05) longer and wider faces than girls, with a larger lower third facial volume relative to middle third facial volume. A significant (P < or = 0.05) effect of headform over facial morphology was found for all angles with a prevalent axial orientation. Conversely, no effect was demonstrated for angles with a sagittal orientation, nor for any other considered parameters. For each sex, the dolichocephalic children had smaller values than the brachycephalic children (i.e., more convex faces in the left-right direction), while the mesocephalic children had intermediate values. No sex x headform interactions were found. Results confirm that a different headform (skull) is associated with a different three-dimensional facial morphology (combined effect of skull and soft tissues), but without size differences.
Abstract: The aim of this investigation was to determine whether attractive children differ in their three-dimensional facial characteristics from nonattractive children of the same age, race, and sex. The facial characteristics of 36 boys and 44 girls aged 8 to 9 years were investigated. Frontal and profile photographs were analyzed independently by 21 judges, and, for each view, four groups were obtained: attractive boys, nonattractive boys, attractive girls, and nonattractive girls. For each child, the three-dimensional coordinates of 16 standardized soft tissue facial landmarks were automatically collected using an infrared system and used to calculate several three-dimensional angles, linear distances, and linear distance ratios. Mean values were computed in the eight groups, and attractive and nonattractive children were compared within sex and view. Most children received a different esthetic evaluation in the separate frontal and profile assessments; concordance in both attractive and nonattractive groups was only 50%. Moreover, three-dimensional facial morphometry was not able to separate attractive and nonattractive children.
Abstract: Head flexion and extension movements near the natural head position (NHP) were analysed for the location of the mean instantaneous centre of rotation (ICR). Forty-six healthy young adults (30 women and 16 men) with sound dentitions, free from cranio-cervical disorders, performed habitual movements that were automatically detected and measured by an infrared three-dimensional motion analyser. ICR and curvature radius were calculated for each movement and subject. In both extension and flexion, ICR position changed during the motion. The movement was symmetrical in all subjects. No gender or flexion/extension differences were found for both ICR position and relevant curvature radius. On average, ICR relative to NHP soft-tissue nasion was located at about 150% of the soft-tissue nasion-right tragus distance, with an angle of about 220 degrees relative to the true horizontal. Results suggest that head flexion or extension is always performed with a combination of rotation (atlanto-occipital joint) and translation (cervical spine) even in the first degrees of motion. Moreover, NHP at rest seems to be some degree more flexed and anterior than head position during movements. These relative positions and their muscular determinants could also influence mandibular posture at rest and during functional movements.
Abstract: The aim of this study was to describe normal nasal growth in a large sample of boys and girls from 6 to 14 years of age, to compare nasal development at 14 years of age with its adult dimensions, and to evaluate differences in growth patterns between males and females.
Abstract: The age- and gender-related shape variations of the craniofacial skeleton in skeletal Class I children were quantified using a Fourier analysis on the pre-treatment lateral head films of 122 orthodontic patients (age range 7-15 years), who were subdivided into six groups for sex and age (2-year intervals). Seven landmarks representative of the maxillo-mandibular sagittal and vertical relationship were identified and digitized. The contiguous landmarks were connected by segments, the form was normalized with respect to its orientation and size, and a Fourier analysis of the contour was performed. Mean values of the cosine and sine coefficients of the first six harmonics in the sex and age classes were computed. The size-standardized outlines of the oldest boys were narrower and longer than the outlines of the youngest boys (differences at gonion, menton, sella and nasion). Shape differences between mean plots in girls were negligible. In the youngest patients, girls had a larger size-independent shape in the mandibular region; their shape was narrower (anterior-posterior direction) and longer (vertical direction) than male shape. In the oldest patients, boys had a larger size-independent shape at gonion, and a narrower shape at articulare and pogonion than girls. Size increased from the youngest to the oldest boys; size differences were not conspicuous in girls. Within an age class, male size was always larger than female. Fourier analysis allowed a global evaluation of the cephalometric forms, with separate quantifications of the age- and gender-related differences in size and shape.
Abstract: Three-dimensional facial morphometry was investigated in a sample of 40 men and 40 women, with a new noninvasive computerized method. Subjects ranged in age between 19 and 32 years, had sound dentitions, and no craniocervical disorders. For each subject, 16 cutaneous facial landmarks were automatically collected by a system consisting of two infrared camera coupled device (CCD) cameras, real time hardware for the recognition of markers, and software for the three-dimensional reconstruction of landmarks' x, y, z coordinates. From these landmarks, 15 linear and 10 angular measurements, and four linear distance ratios were computed and averaged for sex. For all angular values, both samples showed a narrow variability and no significant gender differences were demonstrated. Conversely, all the linear measurements were significantly higher in men than in women. The highest intersample variability was observed for the measurements of facial height (prevalent vertical dimension), and the lowest for the measurements of facial depth (prevalent horizontal dimension). The proportions of upper and lower face height relative to the anterior face height showed a significant sex difference. Mean values were in good agreement with literature data collected with traditional methods. The described method allowed the direct and noninvasive calculation of three-dimensional linear and angular measurements that would be usefully applied in clinics as a supplement to the classic x-ray cephalometric analyses.
Abstract: The purpose of this study was to compare the correlation between three-dimensional soft tissue measurements obtained with three-dimensional digital infrared photogrammetry and two-dimensional data obtained with conventional cephalometry. Facial morphometry was investigated in a group of 20 healthy young men using both systems on each subject. From the lateral radiographs, conventional two-dimensional cephalometric hard and soft tissue data were calculated, while three-dimensional linear and angular soft tissue measurements were computed from the infrared photogrammetry. The correlations between the two sets of measurements were calculated. Three-dimensional soft tissue measurements correlated to cephalometric data primarily contained information useful for esthetic analysis. The soft tissue infrared measurements also allowed evaluation of the general hard tissue situation. Since the soft tissue measurements are calculated with a noninvasive system, they could be computed more frequently during treatment and be used to supplement pretreatment and posttreatment radiographs.
Abstract: Craniofacial growth and development involve both size and shape variations. Shape variations can be assessed independently from size using mathematical methods such as the Fourier series. A method for the reconstruction of outlines starting from selected landmarks and for their Fourier analysis has been developed and applied to analyze the age differences in shape in the tracings of the Bolton standards (lateral view) from 1 to 18 years of age. The size-independent shape of the Bolton standard at 18 years was larger at the chin, at the gonion, and in the anterior cranial base than the shape at 1 year of age. Conversely, the younger shape was larger in the middle part of face, corresponding roughly to the maxillary bone, than the older shape. When standardized for size, growth thus seemed to modify craniofacial shape with progressive lengthening and narrowing. This shape effect was largely overwhelmed by the very evident size increments, and it could be measured only using the proper mathematical methods.
Abstract: In order to assess the relationship between the hard (porion-orbitale) and soft (tragus-orbitale) tissue Frankfurt planes, the relative positions of porion, orbitale, and tragus were evaluated on cephalometric radiographs. A 5-mm radiopaque disk was fixed on the right tragus of 160 white orthodontic patients (65 males aged 7 to 28 years, and 95 females aged 7 to 36 years), and a pre-treatment lateral cephalometric radiograph was taken. In every film the positions of orbitale, porion, and tragus were digitized, and the linear distances between the points, as well as the position of tragus relative to the skeletal structures, were calculated. The linear distances porion-orbitale and tragus-orbitale progressively increased with age, with a low variability in all age classes. The linear distances were always larger in the males than in the females. The tragus was always lower and more anterior than the porion, with vertical distances ranging from 1.2 to 19.8 mm. When the porion-tragus distance was expressed as a percentage of the porion-orbitale distance, the variability decreased. In the age classes, mean percentage horizontal projections from porion ranged from 18 to 23% of the porion-orbitale distance, mean percentage vertical projections ranged from 8 to 15%. Unfortunately, sample variability was large, and, in a single patient, the position of tragus relative to the skeletal structures could be predicted only with a large approximation.
Abstract: The object of this investigation was to determine whether young women considered as beautiful differ in their three-dimensional facial characteristics from normal women of the same age and race.
Abstract: A new method for the quantification of facial asymmetry has been developed and applied to a group of 80 young, healthy, white adults with no craniofacial, dental, or mandibular disorders. The method calculates an asymmetry vector (distance from the symmetry) that allows both the quantification of the absolute degree of asymmetry and its three-dimensional direction and verse.
Abstract: The sexual dimorphism in three-dimensional facial form (size plus shape) was investigated in a sample of 40 men and 36 women by using Euclidean-distance matrix analysis. Subjects ranged in age from 19 to 32 years, had excellent dentitions, and had no craniocervical disorders. For each subject, 16 facial landmarks were automatically collected using a computerized system consisting of two infrared CCD cameras, real-time hardware for the recognition of markers, and software for the three-dimensional reconstruction of landmarks' x, y, z coordinates. Euclidean-distance matrix analysis confirmed the well-known size difference between adult male and female faces (men's faces being 6% to 7% larger than women's faces), while it demonstrated no significant gender differences in three-dimensional facial shape. This result contrasted with the shape differences previously found when separate two-dimensional frontal and sagittal plane projections were analyzed. It could be explained by a relative three-dimensional compensation between the different facial dimensions.
Abstract: Pretreatment lateral skull radiographs of 145 patients aged 7 to 20 years are classified according to an ANB-angle reading corrected for the position of the maxilla and rotation of the jaw. The Euclidean distance matrix analysis is applied to compare the overall facial morphology between Classes I and II. This method differentiates between size and shape and localizes those areas that differ the most. Statistically significant different facial morphologies were demonstrated in the 32 patients aged 15 years or more. The younger patients with skeletal Classes I and II did not possess these different morphological characteristics. The results show that standard cephalometric classification criteria do not always correlate to actual differences in the overall facial morphology.
Abstract: The profiles of 83 healthy young adults were traced from right-side photographs, and then digitized with an image analyzer; each profile thus consisted of a series of coordinates. A dedicated computer program using Fourier analysis resulted in an equation of a curve that interpolated all profile points. By means of cluster analysis, profile equations were divided; two clusters each were found for male and female subjects. A mean profile was calculated for each of the clusters, so that four mean profiles were obtained. These profiles were compared with esthetic parameters found in literature; the results showed that the conventional parameters could sometimes give misleading information for orthodontic and craniofacial orthopedic treatment plans.
