Three-Dimensional Facial Anthropometric Analysis With and Without Landmark Labelling: Is There a Real Difference?

INTRODUCTION: The actual role of landmarks labeling before three-dimensional (3D) facial acquisition is still debated. In this study, several measurements were compared among textured labeled (TL), unlabeled (NL), and untextured (NTL) 3D facial models. MATERIALS AND METHODS: The face of 50 subjects was acquired through stereophotogrammetry. Landmark coordinates were extracted from TL, NL, and NTL facial models, and 33 linear and angular measurements were calculated, together with surface area and volume. Accuracy of measurements among TL, NL, and NTL models was assessed through calculation of relative technical error of measurement (rTEM). The intra- and inter-observer errors for each type of facial model were calculated. RESULTS: Intra- and inter-observer error of measurements increased passing from textured to NTL and NL 3D models. Average rTEMs between TL models, and NTL and NL models were 4.5 ±â€Š2.6% and 4.7 ±â€Š2.8%, respectively, almost all measurements being classified as "very good" or "good." Only for orbital height and its inclination, mandibular ramus length, nasal convexity, alar slope angle, and facial divergence, rTEM was classified as "moderate" or "poor." CONCLUSIONS: Accuracy and precision of measurements decrease when landmarks are not previously labeled; attention must be taken when measurements have a low magnitude or involve landmarks requiring palpation.

Distinctive facial features in Andersen-Tawil syndrome: A three-dimensional stereophotogrammetric analysis.

Andersen-Tawil syndrome (ATS) is a rare potassium channelopathy causing periodic paralysis, cardiac arrhythmias, and dysmorphic features. A detailed analysis of the face could facilitate diagnosis of ATS, as approximately 30% of patients do not show variants in KCNJ2 gene, and diagnosis is established by clinical findings. We aimed to characterize the face in ATS through a quantitative approach, as facial anomalies may be unnoticed on visual inspection. Facial images of 12 subjects with genetically confirmed ATS (six males, six females, age 5-67 years) were acquired through stereophotogrammetry. Using 38 soft-tissue landmarks, linear distances, angles, and ratios were calculated and expressed as z-score values, with reference to 477 healthy subjects matched for sex and age. All patients showed decreased lower facial height with shortening of philtrum (mean z-score ± SD: -1.5 ± 0.9), smaller mid and lower facial depths (-1.9 ± 0.7; -2.3 ± 0.9), short palpebral fissures (right -1.2 ± 0.4; left -1.6 ± 0.6), smaller mandibular ramus length (-2.1 ± 0.4), and increased nasal width/length ratio (1.4 ± 0.5) with smaller nostril axis length (right -1.8 ± 0.8, left -1.6 ± 0.7). Hypertelorism and low-set ears were detected in two-thirds of patients. The study quantified facial dysmorphysm in ATS, extending information about known features, and detecting unrecorded philtrum and nostril characteristics, which may be distinctive traits of the disorder.

3D facial morphometry in Italian patients affected by Aicardi syndrome.

Aicardi syndrome (AIC) is a rare congenital neurodevelopmental disorder of unknown etiology, that affects almost exclusively females, originally characterized by corpus callosum agenesis, chorioretinal lacunae, and infantile spasms. The current diagnostic criteria also include qualitative facial features (prominent premaxilla, upturned nasal tip, decreased nasal bridge angle, sparse lateral eyebrows, and microphthalmia) that still need quantification. A three-dimensional (3D) photogrammetric assessment of 11 Italian females, age 7-32 years, who satisfied AIC criteria, was performed. Linear distances and angles were computed from soft-tissue facial landmarks coordinates. The z-score values were calculated using data of 850 healthy reference females matched for age and compared by Mann-Whitney test (p < .01). Patients showed a shorter philtrum and right side orbital height (mean z-scores: -1.7, -0.9), shorter superior, middle, and inferior facial depths (mean z-scores: -1.3, -2.2, -2.3), and a smaller length of mandibular ramus (mean z-score: -2.1); conversely, they showed larger nasal and lower facial widths, and lower facial convexity (mean z-scores: 1.7, 1.4, 2.4). The inclinations of the orbit versus the true horizontal were increased bilaterally (mean z-scores: 1.8, 1.1). Some common facial abnormalities were quantified in AIC patients using a noninvasive instrument. They may help clinicians in performing a definite AIC diagnosis in atypical or doubt cases.

The Effect of Orthognathic Surgery on Soft-Tissue Facial Asymmetry: A Longitudinal Three-Dimensional Analysis.

In modern orthognathic surgery, the functional results cannot disregard a good aesthetic outcome. In this study, a stereophotogrammetric longitudinal analysis of the symmetry of facial thirds was performed in 18 patients affected by Class III skeletal malocclusion, with clinical asymmetry, treated with a bimaxillary osteotomy. Their 3-dimensional facial images were acquired in the preoperative phase and 6, 12, and 24 months after surgery, and compared to those obtained in a control group of 23 subjects with Class I skeletal occlusion, without clinical asymmetry and no history of traumas or alterations at the maxillo-facial area. Images of the hemi-faces of the subjects were divided into thirds (upper, middle, lower), mirrored and superimposed to their contralateral ones; soft-tissue facial symmetry was obtained as the root mean square distance between the hemi-faces in the three thirds.In patients, no significant differences in facial symmetry (root mean square distance) were found among the study time points (analysis of variance, P > 0.05); the lower facial third was more asymmetric than the upper one (Tukey honestly significant difference P < 0.05). Patients were significantly more asymmetric than the control subjects (Student t, P < 0.05). In conclusion, patients with Class III malocclusion exhibited a higher level of facial asymmetry than control subjects; their asymmetry did not change significantly in the different phases of the surgical and orthodontic treatment and throughout a 24-month follow-up. In skeletal Class III patients, bimaxillary osteotomy did not modify the level of asymmetry in any facial third.

Relation between volume of sphenoid sinuses and protrusion of Vidian nerve: possible applications to Vidian neurectomy.

PURPOSE: Vidian neurectomy is a surgical procedure applied to different pathological conditions, including chronic rhinitis and sphenopalatine neuralgia. The choice of the correct surgical approach depends upon the possible protrusion of Vidian nerve into the sphenoid sinuses. The present study analyzes the possible relationship between protrusion of Vidian nerve and volume of sphenoid sinuses. METHODS: In total, 320 maxillofacial CT-scans were retrospectively assessed. Subjects equally divided among males and females (age range 18-94 years) were divided into three groups according to the profile of Vidian nerve protrusion: type 1: Vidian nerve inside the sphenoid corpus; type 2: partially protruding into the sphenoid sinus; and type 3: entirely protruding into the sphenoid sinus through a stalk. Volume of sphenoid sinuses was extracted through the ITK-SNAP-free software and automatically calculated. Possible statistically significant differences in prevalence of the three types between males and females were assessed through Chi-squared test (p < 0.05). Differences in volume of sphenoid sinuses in subjects included within the three types were assessed through one-way ANOVA test (p < 0.05), separately for males and females. RESULTS: Type 2 was the most prevalent (46.5%), followed by type 1 (38.8%) and type 3 (14.7%), without significant differences according to sex (p > 0.05). Volume significantly increased passing from type 1 to type 3 both in males (p < 0.01) and in females (p < 0.01). CONCLUSIONS: The results prove the existence of a strict relationship between sphenoid sinuses pneumatization and protrusion of the Vidian canal and give a contribution to the knowledge of this important anatomical variant in endoscopic surgery.

3D Facial morphology in children affected by spinal muscular atrophy type 2 (SMAII).

OBJECTIVES: The main objective of this study was to assess the three-dimensional facial characteristics of children affected by spinal muscular atrophy (SMA), a severe muscular disorder characterized by hypotonia, areflexia, weakness, and respiratory impairment. MATERIALS/METHODS: Stereophotogrammetric facial scans from 22 SMA type II patients aged 2-7 years were obtained. Data were analysed using both inter-landmark distances and principal component analysis and compared with data collected from matched control subjects. RESULTS: Patients had wider transverse facial diameters, but smaller biocular width. Middle and lower anterior face heights were increased, whereas the mandibular ramus was shorter, with a reduced posterior-to-anterior face height ratio. Facial width-to-length ratio was reduced. In the sagittal plane, mandibular body length, and facial divergence were increased, whereas the gonial angles were decreased. In the horizontal plane, lower facial convexity was greater in patients, whereas mandibular convexity was smaller. Patients had smaller and down-slanted eye fissures, with a larger and more vertically developed nose. LIMITATIONS: This study assessed a relatively small number of patients, due to the rare frequency of SMA type II. CONCLUSIONS/IMPLICATIONS: SMA type II children possess peculiar facial alterations that may be due to the altered muscular activity. As feeding problems may derive also by malocclusion and masticatory muscular alterations, a detailed assessment of the craniofacial individual alterations should be considered in the standards of care of these patients.

Use of Machine Learning and Wearable Sensors to Predict Energetics and Kinematics of Cutting Maneuvers.

Changes of directions and cutting maneuvers, including 180-degree turns, are common locomotor actions in team sports, implying high mechanical load. While the mechanics and neurophysiology of turns have been extensively studied in laboratory conditions, modern inertial measurement units allow us to monitor athletes directly on the field. In this study, we applied four supervised machine learning techniques (linear regression, support vector regression/machine, boosted decision trees and artificial neural networks) to predict turn direction, speed (before/after turn) and the related positive/negative mechanical work. Reference values were computed using an optical motion capture system. We collected data from 13 elite female soccer players performing a shuttle run test, wearing a six-axes inertial sensor at the pelvis level. A set of 18 features (predictors) were obtained from accelerometers, gyroscopes and barometer readings. Turn direction classification returned good results (accuracy > 98.4%) with all methods. Support vector regression and neural networks obtained the best performance in the estimation of positive/negative mechanical work (coefficient of determination R2 = 0.42-0.43, mean absolute error = 1.14-1.41 J) and running speed before/after the turns (R2 = 0.66-0.69, mean absolute error = 0.15-018 m/s). Although models can be extended to different angles, we showed that meaningful information on turn kinematics and energetics can be obtained from inertial units with a data-driven approach.

Relationship between sphenoid sinus volume and protrusion of internal carotid artery and optic nerve: a 3D segmentation study on maxillofacial CT-scans.

PURPOSE: Anatomy of sphenoid sinuses has acquired a growing importance with the diffusion of transsphenoidal surgical procedures. A common risk in these practices is the damage of internal carotid artery (ICA) and optic nerve (ON), which may protrude into the sphenoid air cavities. This study aims at analysing the relationships between sphenoid sinuses volume and protrusion of ICA and ON. METHODS: 260 head CT-scans were retrospectively analysed (equally divided among males and females, age range 20-92 years). Volume was segmented through ITK-SNAP software. In addition, the subjects were classified into four groups: no protrusion of any structure (group 1), protrusion of ICA (group 2), protrusion of ON (group 3), protrusion of both ICA and ON (group 4). Possible statistically significant differences in prevalence of the four groups according to gender were assessed through Chi-squared test (p < 0.05). Differences in volume between the four groups were assessed through one-way ANOVA test (p < 0.05), separately for males and females. RESULTS: Group 1 was the most frequent (40.0%), followed by group 4 (27.7%) and group 2 (18.5%), without any difference according to gender. For what concerns volume, cases of ICA and concomitant ICA + ON protrusion had significantly larger sinuses, whereas isolated ON protrusion did not modify sinus volume. CONCLUSIONS: Results show that protrusion of ICA is positively related with the volume of sphenoid sinuses, whereas the same relation was not verified for ON: surgeons should accurately consider possible ON protrusion in each case, as it may occur independently from sphenoid sinuses volume.

Anatomy of the pterygopalatine fossa: an innovative metrical assessment based on 3D segmentation on head CT-scan.

PURPOSE: The pterygopalatine fossa is an important anatomical structure for several surgical and anaesthesiologic procedures; yet, very few data are available about its size. This study aims at providing a metrical assessment of pterygopalatine fossa through an innovative 3D segmentation procedure on head CT-scans. METHODS: CT-scans from 100 patients (50 males and 50 females) aged between 18 and 85 years were chosen for the study. Right and left pterygopalatine fossae were segmented through ITK-SNAP open source software. Height and volume were calculated on the acquired 3D models. In addition, anterior-posterior nasal spine distance, upper facial height (nasion-prosthion) and biorbital breadth (ectoconchion-ectoconchion) were measured as well. Statistically significant differences of height and volume according to sex and side were assessed through two-way ANOVA test: sexually dimorphic measurements were further assessed through one-way ANCOVA test using the three cranial measurements as covariates (p < 0.05). RESULTS: On average pterygopalatine fossa height was 24.1 ± 3.5 mm in males, and 22.8 ± 3.4 mm in females, whereas volume was 0.930 ± 0.181 cm3 in males and 0.817 ± 0.157 cm3 in females, with statistically significant differences according to sex (p < 0.05), but not to side (p > 0.05); interaction was negligible for both the measurements. ANCOVA test verified that sexual dimorphism of both measurements is independent from general cranial size (p < 0.05). CONCLUSIONS: The present study highlighted the sexual dimorphism of pterygopalatine fossa: results may improve the knowledge of this anatomical structure difficult to explore, but crucial in several fields of clinics and surgery.

Quantification of odontological differences of the upper first and second molar by 3D-3D superimposition: a novel method to assess anatomical matches.

PURPOSE: The introduction of modern 3D image acquisition systems has enabled researchers to develop novel procedures for personal identification. The present study aimed to assess differences between dental scans belonging to the same or different subjects, through an innovative 3D-3D superimposition and registration method. METHODS: Twelve subjects (6 males and 6 females) with pre- and post-orthodontic treatment dental casts were recruited. A 3D scan from each cast was obtained through a laser scanner and the 3D model of the upper first and second molar on the post-treatment cast was superimposed on the pre-treatment scan, for a total of 12 matches and 100 mismatches. Point-to-point RMS (root mean square) distance was then calculated. Student's t test verified possible statistically significant differences according to group (matches/mismatches; p < 0.05). RESULTS: In case of matches, on average the point-to-point distance RMS was 0.29 mm (SD: 0.08 mm), while it was 0.94 mm (SD: 0.30 mm) for mismatches, with a statistically significant difference (p < 0.001). CONCLUSIONS: Results show that the novel procedure was able to distinguish matches from mismatches through an RMS threshold (0.50 mm): a possible method for personal identification is described, which needs to be verified through the application to a larger sample of casts.

Application of 3D models of palatal rugae to personal identification: hints at identification from 3D-3D superimposition techniques.

Palatal rugae are known in literature as individualizing anatomical structures with a strong potential for personal identification. However, a 3D assessment of their uniqueness has not yet been performed. The present study aims at verifying the uniqueness of 3D models of the palate. Twenty-six subjects were recruited among the orthodontic patients of a private dental office; from every patient, at least two dental casts were taken in different time periods, for a total of 62 casts. Dental casts were digitized by a 3D laser scanner (iSeries, Dental Wings©, Montreal, Canada). The palatal area was identified, and a series of 250 superimpositions was then performed automatically through VAM©software in order to reach the minimum point-to point distance between two models. In 36 matches the models belonged to the same individual, whereas in 214 mismatches they came from different subjects. The RMS (root mean square) of point-to-point distances was then calculated by 3D software. Possible statistically significant differences were assessed through Mann-Whitney test (p < 0.05). Results showed a statistically significant difference in RMS mean point-to-point distance between matches (mean 0.26 mm; SD 0.12) and mismatches (mean 1.30; SD 0.44) (p < 0.0001).All matches reached an RMS value below 0.50 mm. This study first provided an assessment of uniqueness of palatal rugae, based on their anatomical 3D conformations, with consequent applications to personal identification.

Are Portable Stereophotogrammetric Devices Reliable in Facial Imaging? A Validation Study of VECTRA H1 Device.

PURPOSE: Modern 3-dimensional (3D) image acquisition systems represent a crucial technologic development in facial anatomy because of their accuracy and precision. The recently introduced portable devices can improve facial databases by increasing the number of applications. In the present study, the VECTRA H1 portable stereophotogrammetric device was validated to verify its applicability to 3D facial analysis. MATERIALS AND METHODS: Fifty volunteers underwent 4 facial scans using portable VECTRA H1 and static VECTRA M3 devices (2 for each instrument). Repeatability of linear, angular, surface area, and volume measurements was verified within the device and between devices using the Bland-Altman test and the calculation of absolute and relative technical errors of measurement (TEM and rTEM, respectively). In addition, the 2 scans obtained by the same device and the 2 scans obtained by different devices were registered and superimposed to calculate the root mean square (RMS; point-to-point) distance between the 2 surfaces. RESULTS: Most linear, angular, and surface area measurements had high repeatability in M3 versus M3, H1 versus H1, and M3 versus H1 comparisons (range, 82.2 to 98.7%; TEM range, 0.3 to 2.0 mm, 0.4° to 1.8°; rTEM range, 0.2 to 3.1%). In contrast, volumes and RMS distances showed evident differences in M3 versus M3 and H1 versus H1 comparisons and reached the maximum when scans from the 2 different devices were compared. CONCLUSION: The portable VECTRA H1 device proved reliable for assessing linear measurements, angles, and surface areas; conversely, the influence of involuntary facial movements on volumes and RMS distances was more important compared with the static device.

A Quantitative Assessment of Lip Movements in Different Facial Expressions Through 3-Dimensional on 3-Dimensional Superimposition: A Cross-Sectional Study.

PURPOSE: The quantitative assessment of facial modifications from mimicry is of relevant interest for the rehabilitation of patients who can no longer produce facial expressions. This study investigated a novel application of 3-dimensional on 3-dimensional superimposition for facial mimicry. MATERIALS AND METHODS: This cross-sectional study was based on 10 men 30 to 40 years old who underwent stereophotogrammetry for neutral, happy, sad, and angry expressions. Registration of facial expressions on the neutral expression was performed. Root mean square (RMS) point-to-point distance in the labial area was calculated between each facial expression and the neutral one and was considered the main parameter for assessing facial modifications. In addition, effect size (Cohen d) was calculated to assess the effects of labial movements in relation to facial modifications. RESULTS: All participants were free from possible facial deformities, pathologies, or trauma that could affect facial mimicry. RMS values of facial areas differed significantly among facial expressions (P = .0004 by Friedman test). The widest modifications of the lips were observed in happy expressions (RMS, 4.06 mm; standard deviation [SD], 1.14 mm), with a statistically relevant difference compared with the sad (RMS, 1.42 mm; SD, 1.15 mm) and angry (RMS, 0.76 mm; SD, 0.45 mm) expressions. The effect size of labial versus total face movements was limited for happy and sad expressions and large for the angry expression. CONCLUSION: This study found that a happy expression provides wider modifications of the lips than the other facial expressions and suggests a novel procedure for assessing regional changes from mimicry.

Can Volumetric and Morphological Variants of Sphenoid Sinuses Influence Sinuses Opacification?

Improvements in computed tomography and in functional endoscopic sinus surgery have recently increased interest toward paranasal sinus anatomy and anatomic variations that can be observed in patients affected by sinusitis. Isolated sphenoid sinusitis is a relatively rare pathology, often related to nonspecific symptoms, therefore making diagnosis difficult. The correlation between this type of sinusitis and anatomical variants remains unclear.The authors' aim was to retrospectively revise paranasal sinuses computed tomography scans of patients affected by sphenoid sinusitis, compared with a control group, analyzing the types of sphenoid sinus and the presence of aberrant pneumatization, and performing a segmentation of the sphenoid sinuses to calculate the volumes.Sphenoid sinuses of 60 patients affected by sinus opacification, compared with a control group, were segmented. Type of sinus (sellar, presellar, postsellar) and presence of aberrant pneumatization were assessed as well. Possible statistically significant differences in volumes according to sex and group were assessed through 2-way ANOVA test (P < 0.05). Post-hoc test was assessed through Student t test. χ test was applied in order to verify the statistically significance of differences in frequency of different types of sinus pneumatization variants (P < 0.05).Average volume of sphenoid sinuses in males was of 7.672 cm and of 7.751 cm in females within the group of patients; statistically significant differences in volume were found according to sex (P: 0.342), but not between the patients and control group (P: 0.0929). Post-hoc test verified that males affected by sinus opacification showed smaller volumes in comparison with the control males (P < 0.05). In addition, patients by affected sinus opacification showed more frequently the postsellar type and were less affected by pneumatization variants of the sphenoid bone than the control group (P < 0.05).This study first suggests the possible protective role of variants of pneumatization in the development of sphenoid sinus opacification.

The face in marfan syndrome: A 3D quantitative approach for a better definition of dysmorphic features.

Marfan syndrome (MFS) is a rare hereditable disorder of connective tissue caused by mutations in the fibrillin-1 gene FBN1. Timely diagnosis of MFS is essential to prevent life-threatening cardiovascular complications; nevertheless it can be difficult owing to the phenotypic variability of the syndrome. No clear quantitative definition of facial abnormalities associated with MFS is available. The aim of this study was to improve the definition of the facial phenotype associated with MFS and to verify the usefulness of a 3D noninvasive quantitative approach for its early recognition. 3D facial images of 61 Italian subjects with MFS, aged 16-64 years (21 males, 38 ± 15 years; 40 females, 41 ± 13 years) were obtained by stereophotogrammetry. From the coordinates of 17 soft-tissue facial landmarks, linear distances and angles were computed; z score values were calculated to compare patients with healthy reference subjects (400 males, 379 females) matched for sex and age. Student's t test was used for statistical comparisons. All subjects with MFS showed greater facial divergence (P < 0.001; mean z score +1.9) and a lower facial height index (P < 0.001; mean z score -1.9) than reference subjects, both values being influenced by a shorter mandibular ramus (P < 0.001; mean z score -1.9) and a mild but significant increase in facial height (P < 0.001; mean z score +1.2). Palpebral down-slanting was found in 85% of MFS subjects. There were no sex differences. Quantitative abnormalities identified in this study enrich information about the facial dysmorphism in MFS and confirm its usefulness for early recognition of the disease. Clin. Anat. 31:380-386, 2018. © 2017 Wiley Periodicals, Inc.

Assessing Normal Smiling Function Through 3D-3D Surfaces Registration: An Innovative Method for the Assessment of Facial Mimicry.

Smiling has a great importance, both from a functional and an aesthetic point of view. The introduction of modern 3D acquisition and elaboration methods may provide additional help in the evaluation of facial mimicry. This study aims at proposing an innovative method to assess facial and labial movements in different types of smiles. Twenty healthy subjects (10 males, 10 females, mean age 27.5 years, SD 4.5 years), were recorded through a stereophotogrammetric system in neutral position and in three types of smiles: Mona-Lisa smile, canine smile, full-denture smile. All the 3D smiling models were superimposed on the corresponding neutral one and point-to-point root mean square (RMS) differences were computed. Labial surface areas in rest position and during each smile were calculated as well, together with the percentage modification in different types of smile. RMS values (facial and labial models), labial surface areas and percentage modifications were compared through ANCOVA tests to verify possible statistically significant differences according to sex and type of smile (p < 0.05). Intercanthal labial width was considered a covariate. RMS values progressively increased from Mona-Lisa to full-denture smile; statistically significant differences were found among all types of smiles, both for facial and labial models (p < 0.05), while no statistically significant sex and sex × smile interactions were found (p > 0.05). Labial surface and percentage of modification showed statistically significant differences according to both sex and type of smile (p < 0.05). The study provides a novel contribution to the field of sexual dimorphism in smiling. Level of Evidence V This journal requires that authors assign a level of evidence to each article. For a full description of these evidence-based medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Anatomical characteristics of greater palatine foramen: a novel point of view.

PURPOSE: Anatomy of greater palatine foramen is important for maxillary nerve blocks, haemostatic procedures, and the treatment of neuralgia; although metrical data are available about its collocation, still several aspects need to be explored, such as the influence of the cranium size. METHODS: The position of greater palatine foramen was assessed on 100 skulls through six measurements (distances from intermaxillary suture, posterior palatal border, posterior nasal spine, and incisive foramen; palatal length; relative position on palatal length) and two angles (angles at incisive foramen and greater palatine foramen). Maximum cranial length, maximum cranial breadth, cranial height and bizygomatic breadth, horizontal cephalic index, and Giardina Y-index were evaluated. Possible differences according to sex and side were assessed through two-way ANOVA (p < 0.05). Measurements showing sexual dimorphism were further assessed through one-way ANCOVA including cranial parameters as covariates (p < 0.05). RESULTS: Distances of the greater palatine foramen from intermaxillary suture, incisive foramen, posterior palatal border, posterior nasal spine, palatal length, and position of the greater palatine foramen on the palatal length were statistically different according to sex (p < 0.05), independently from general cranial dimensions but for the distance from the posterior palatal border. The angle at the incisive foramen and distances from intermaxillary suture and from posterior nasal spine showed statistically significant differences according to side (p < 0.05). CONCLUSIONS: Results highlight that most of sexually dimorphic measurements useful for pinpointing the greater palatal foramen do not depend upon the cranium size. A more complete metrical assessment of the localization of the greater palatine foramen was provided.

Prevalence of ponticulus posticus in a Northern Italian orthodontic population: a lateral cephalometric study.

PURPOSE: The term "ponticulus posticus" refers to a partial or complete bony arch over the vertebral artery as it crosses the superolateral surface of the posterior arch of the atlas. This anatomical modification is linked to different symptoms, ranging from neckache to headache and migraine. This bony arch may also be incorrectly assessed during orthopaedic surgery for fixation of C1-C2, with consequent risk of damaging the vertebral artery. Its frequency in the general population has been widely analysed by literature in different geographic contexts, but an analysis of the prevalence of such feature in the Italian population is still missing. METHODS: A Northern Italian orthodontic sample was analysed to assess the prevalence of ponticulus posticus. Lateral teleradiographies of 221 patients were examined. All the patients underwent lateral cephalometry for odontoiatric purposes and none of them was affected by congenital diseases or skeletal deformities. RESULTS: In the analysed sample, ponticulus posticus had a prevalence of 7.7 % for the complete form, and 9.0 % for the incomplete form. Complete and partial forms were observed, respectively, in 8.8 and 11.0 % of males, and in 6.9 and 7.7 % of females, without statistically significant differences. CONCLUSIONS: The current investigation provided the first data concerning the frequency of ponticulus posticus in Italy: further studies are needed to widen the sample, verify possible regional variations and improve the analysis by more advanced radiological examinations such as CT and cone beam CT scans.

A Quantitative Analysis of Lip Aesthetics: The Influence of Gender and Aging.

INTRODUCTION: The quantitative analysis of sexual dimorphism of facial structures may valuably support reconstructive and feminization surgery, thanks to the estimation of metrical thresholds useful for distinguishing male and female traits. This study aims at verifying the metrical characteristics of female and male lips, to provide indications for aesthetic surgery. METHODS: Thirty healthy Caucasian volunteers (20 men and 20 women) were divided into two groups according to age: 21-34 years and 45-65 years. Arches and the cutaneous (external) and mucosal (internal) labial surfaces were reproduced by stone models, and digitised using a computerised electromechanical instrument. Area, volume and thickness were measured separately for the upper and lower lips, and compared between sexes and ages by Student's t test, and multinomial logistic regression. RESULTS: All lip measurements were larger in males than in females; upper lip thickness best divided males from females, adopting a 9.5-mm threshold (percentage of correct diagnosis: 85 %). Young subjects always showed higher measurements than old subjects; lower lip thickness provided the highest percentage of correct age diagnosis (85 %, adopting a 13.8-mm threshold). CONCLUSION: This study provides novel thresholds that may contribute to the assessment of adequate reconstruction of lips in aesthetic surgery. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Abnormal Variations in the Facial Soft Tissues of Individuals With Down Syndrome: Sudan Versus Italy.

OBJECTIVE: To provide quantitative information about the facial soft tissue of Italian and Northern Sudanese subjects with Down syndrome by using summary anthropometric measurements. DESIGN, SETTING, AND PATIENTS: The three-dimensional coordinates of soft tissue facial landmarks were obtained using a computerized digitizer in 54 Italian subjects with Down syndrome (20 females and 34 males, 13 to 52 years), in 64 Northern Sudanese subjects with Down syndrome (18 females and 46 males, 5 to 34 years), and in 578 Italian and 653 Northern Sudanese reference subjects, matched for sex and age. From the landmarks, 16 facial dimensions were calculated. Data from subjects with Down syndrome were compared with those collected from control individuals by computing z scores. Two summary anthropometric measurements for quantifying craniofacial variations were obtained: the mean z score (an index of overall facial size) and its standard deviation, the craniofacial variability index (an index of facial harmony). RESULTS: In subjects with Down syndrome, facial size was significantly smaller and craniofacial variability was significantly greater than in typically developed individuals; 93% of Italian and 81% of Northern Sudanese subjects with Down syndrome had one or both values outside the normal interval. Overall, Italian subjects with Down syndrome differed more from the norm than did those from Northern Sudan. In the Northern Sudanese subjects, the mean z scores and the craniofacial variability index were significantly influenced by age: Older Northern Sudanese subjects with Down syndrome had smaller mean z scores and craniofacial variability index values than younger subjects. CONCLUSIONS: The two ethnic groups had different alterations in their soft tissue facial dimensions that were partially influenced by age.