Restoration of the Lateral Canthus and Stabilization of the Lower Eyelid After Failed Esthetic Lateral Canthoplasty.

BACKGROUND: An improper procedure of esthetic lateral canthoplasty can lead to lateral canthal deformity with other complications. To ensure proper canthal contour and eyelid function, the lateral canthus must be restored and the lower eyelid must be stabilized. METHODS: This was a retrospective study that included a group of consecutive patients who had failed esthetical lateral canthoplasty between 2020 and 2022. All patients underwent the modified lateral tarsal strip procedure to restore the normal anatomy of the lateral canthus and stabilize the lower eyelid. Clinical data (age, sex, laterality, follow-up, ocular symptoms, previous medical history, and lateral canthal deformity) were collected. Preoperative and postoperative photographs were analyzed for cosmetic outcomes. RESULTS: Among the 15 female patients, 25 eyelids were treated, including both eyes in 10 patients and only the left eye in 5 others. The mean age was 32.6 years. The mean follow-up was 13.34 months. All the patients had undergone esthetic lateral canthoplasty with other esthetic surgeries. Lateral canthus deformities include canthal webbing, rounding canthus, eyelid margin defect, remnant raw surface, mucosal exposure, lower eyelid retraction, sclera show, ectropion, symblepharon, and lagophthalmos. All the patients exhibited esthetically satisfactory results with improved ocular symptoms. In statistical analysis, horizontal palpebral aperture, vertical palpebral aperture, MRD2, and lateral canthus angle were statistically different pre to postprocedure (paired t test, P < 0.001). CONCLUSIONS: Restoration of the lateral canthus and stabilization of the lower eyelid using the modified lateral tarsal strip procedure showed good functional and cosmetic outcomes in patients who had failed lateral canthoplasty.

Lower Eyelid Transcutaneous Blepharoplasty, Minimizing Complications and Correction of Lower Eyelid Malposition.

The periocular area is one of the first and most noticeable areas affected by ageing. Common signs of lower lid ageing include rhytids, prominent eye bags caused by prolapse of orbital fat pads, increased lid laxity leading to lid malpositioning, and deepening of tear troughs, all of which give a sunken aged appearance. Lower lid transcutaneous blepharoplasty can correct most of these problems providing excellent long-term aesthetic outcomes with minimal downtime for the patient. However, lower eyelid anatomy is complex, and a thorough understanding of its structure and function is needed to avoid serious complications such as lid malpositioning and blindness. In this review, we present the anatomy of the lower lid and useful surgical techniques to circumvent and avoid such complications.

Anthropometric Periocular Soft Tissue Analysis From Preadolescence to Young Adulthood: Photogrammetric Measurements.

ABSTRACT: The periocular region has a central role in the prediction of ethnicity, understanding emotional expression, age, and sex. The aim of this study was to determine the sex-related growth changes in the periocular region of Turkish preadolescents, adolescents, and young adults. The study included a total of 234 individuals (preadolescents: 34 females and 40 males; adolescents: 40 females, 40 males, and young adults: 40 males and 40 females). A total of 7 periocular parameters (3 bilateral, 3 unilateral linear, and 1 angular measurement) were analyzed statistically to determine sex-related differences. The palpebral fissure and canthal indexes were also calculated. Of the 14 periocular measurements, 9 were found to be sexually dimorphic in certain age groups ( P < 0.05). Right-left palpebral fissure width and left palpebral fissure height were significantly different between young adult males and females ( P = 0.018, P = 0.013, and P = 0.027, respectively). A significant sexual dimorphism was observed for outercanthal distance and canthal index in 3 age groups ( P < 0.05). The data collected in this study may serve as a sex-dependent database source for the Turkish population during normal growth from preadolescence to young adulthood. The present study results would be useful for planning and designing aesthetic and post-traumatic surgical interventions in the periocular region as well as personal identification in this population.

Anatomical Evaluation of Zygomaticus Major Muscle With Relation to Orbicularis Oculi Muscle and Parotid Duct.

OBJECTIVES: To evaluate morphological properties of the zygomaticus major (ZMj) and demonstrate its detailed anatomical relationships with the orbicularis oculi (OOc) and the parotid duct (PD). METHODS: Fifteen formalin fixed adult cadaver heads (7 males /8 females) aged between 45 and 92 years were dissected to reveal the ZMj, OOc, PD. Shape, lengths and thickness of the ZMj, positional relationships of the ZMj with respect to the OOc and PD (overlap, neighboring, being separate) were determined. Topographic localization of the ZMj according to lateral and medial canthi, tragus, mental tubercle and angle of mandible was evaluated. RESULTS: The shape of the ZMj was observed as band like in 15/29 (51%), fan like in 10/29 (34%) and bifid in 4/29 (13%) sides. Position of the ZMj with respect to the OOc and distal part of the PD was not constant. The ZMj was overlapped by the OOc in 15/29 (52%) sides while they were adjacent in 14/29 (48%) sides. The ZMj overlapped the distal part of PD in 16/29 (%55) sides. They were separate in 10/29 (35%) sides and adjacent in 3/29 (10%) sides. Topographic location of the ZMj with respect to lateral and medial canthii, tragus, angle of mandible and mental tubercle was demonstrated. No statistically significant relationships were found between the ZMj measurements with head circumference and face length. No statistically significant differences were found between sides and gender in terms of the ZMj morphology (P > 0.05). CONCLUSION: This study demonstrates the morphological features and topography of the ZMj along with its relationships with the OOc and PD that would be essential for clinical implications.

Illusory feature slowing: evidence for perceptual models of global facial change.

Upright static faces are widely thought to recruit holistic representations, whereby individual features are integrated into nondecomposable wholes for recognition and interpretation. In contrast, little is known about the perceptual integration of dynamic features when viewing moving faces. People are frequently exposed to correlated eye and mouth movements, such as the characteristic changes that accompany facial emotion, yawning, sneezing, and laughter. However, it is unclear whether the visual system is sensitive to these dynamic regularities, encoding facial behavior relative to a set of dynamic global prototypes, or whether it simply forms piecemeal descriptions of feature states over time. To address this question, we sought evidence of perceptual interactions between dynamic facial features. Crucially, we found illusory slowing of feature motion in the presence of another moving feature, but it was limited to upright faces and particular relative-phase relationships. Perceptual interactions between dynamic features suggest that local changes are integrated into models of global facial change.

Craniofacial morphologic parameters in a Persian population: an anthropometric study.

Limited data are available regarding the reference ranges of facial proportions of the Persian population in Iran. This study aimed to establish the reference range of craniofacial anthropometric measurements in an adult Iranian population. On 100 individuals (men = women), aged 18 to 30 years with normal faces and occlusions, 34 linear and 7 angular measurements as well as 24 indices were calculated. The difference of measurements between men and women were evaluated by paired t-test. The data were compared with the norms of North American whites using 1-sample t-test. The subjects belonged to 5 ethnic groups (57% from Fars, 14% from Kord, 11% from Azari, 10% from Gilaki-Mazani, and 2% from Lor). All head measurements were greater in men except for the head index and the head height. The subjects had leptoprosopic faces. The intercanthal width was almost one third of the biocular width and greater than the eye fissure length. Although the nose width of women was significantly smaller, both sexes had leptorrhine noses. The chin height and lower chin height were greater in men. In comparison with North American whites, considerable differences were found regarding head height and width, biocular width, nose height, face height, mouth width, and upper chin height. In conclusion, the reference range of craniofacial anthropometric measurements established for the Iranian population might be efficiently used for esthetic treatments.

Three-dimensional analysis of facial shape and symmetry in twins using laser surface scanning.

OBJECTIVES: Three-dimensional analysis of facial shape and symmetry in twins. SETTING AND SAMPLE POPULATION: Faces of 37 twin pairs [19 monozygotic (MZ) and 18 dizygotic (DZ)] were laser scanned at the age of 15 during a follow-up of the Avon Longitudinal Study of Parents and Children (ALSPAC), South West of England. MATERIAL AND METHODS: Facial shape was analysed using two methods: 1) Procrustes analysis of landmark configurations (63 x, y and z coordinates of 21 facial landmarks) and 2) three-dimensional comparisons of facial surfaces within each twin pair. Monozygotic and DZ twins were compared using ellipsoids representing 95% of the variation in landmark configurations and surface-based average faces. Facial symmetry was analysed by superimposing the original and mirror facial images. RESULTS: Both analyses showed greater similarity of facial shape in MZ twins, with lower third being the least similar. Procrustes analysis did not reveal any significant difference in facial landmark configurations of MZ and DZ twins. The average faces of MZ and DZ males were coincident in the forehead, supraorbital and infraorbital ridges, the bridge of the nose and lower lip. In MZ and DZ females, the eyes, supraorbital and infraorbital ridges, philtrum and lower part of the cheeks were coincident. Zygosity did not seem to influence the amount of facial symmetry. Lower facial third was the most asymmetrical. CONCLUSION: Three-dimensional analyses revealed differences in facial shapes of MZ and DZ twins. The relative contribution of genetic and environmental factors is different for the upper, middle and lower facial thirds.

Three-dimensional analysis of soft tissue changes in full-face view after surgical correction of skeletal class III malocclusion.

OBJECTIVE: The objective of this study was to evaluate changes in soft tissue in full-face view because of surgical correction of skeletal Class III malocclusion, using 3-dimensional (3D) laser scanning. METHODS: Twenty-seven subjects with skeletal Class III malocclusion [11 males; mean age (SD), 24.0 (5.7) years] underwent bilateral sagittal split ramus osteotomy for mandibular setback combined with Lefort I osteotomy with/without maxillary advancement. Twelve patients (group 1) had mandibular setback surgery, and the other 15 (group 2) had combination surgery. Lateral cephalograms and 3D facial scan images were assessed preoperatively and postoperatively. The facial widths upon superimposition of 3D facial images were measured in the same coordinates using a Rapidform 2006 system. Paired and independent t tests were done for statistical analysis. RESULTS: The midface soft tissue broadened significantly above the cheilion plane postoperatively (P < 0.05). A larger change was observed nearer to subnasale plane, and a similar trend was seen among the horizontal planes in 1- or 2-jaw surgery groups. The widths from the exocanthion plane to the subnasale plane increased more in group 2 [mean (SD), 4.45 (2.45) mm, 8.71 (2.92) mm, and 7.62 (3.13) mm] than those in group 1 [mean (SD), 1.26 (0.97) mm, 1.84 (1.06) mm, and 1.35 (0.65) mm], and this difference was significant (P < 0.05). There was a decrease below the cheilion plane with mandibular setback between groups, but this difference was not significant. CONCLUSIONS: The measurement method used here for the shape outline of the lateral parts of the face could provide quantitative data for the clinical evaluation and objective analysis of the human face in full-face view. The midface soft tissue in subjects with skeletal Class III malocclusion exhibited a greater increase in width after bimaxillary surgery procedures than mandibular setback-only surgery.

Evaluation of some facial anthropometric parameters in an Iranian population: infancy through adolescence.

OBJECTIVES: By finding the mean value of anthropometric parameters in normal samples of a population, it is possible to create a template for facial analysis. The aim of our study was to measure the anthropometric parameters in 0- to 12-year-old girls of Fars ethnic origin in the Northeast of Iran. STUDY DESIGN: Six hundred sixty-two newborn to 12-year-old girls of Fars ethnic origin participated in the study. A digital camera was used to take frontal full-face photographs of each child. Thirteen measurements were taken with the Smile Analyzer software: al-al, ch-ch, en-en, ex-ex, ft'-ft', go'-go', t-t, zy'-zy', n'-gn', n'-sn, t-g', t-gn', t-sn. Data were analyzed using the SPSS software at the significance level of 0.05. RESULTS: In almost all parameters, we found significant growth acceleration between 2 and 4 years as well as 5 and 6 years of age. Another growth spurt was seen between 9 and 11 years, although it was less noticeable. Comparing the linear regression equations suggests that different craniofacial dimensions do not grow similarly. CONCLUSIONS: By age, craniofacial dimensions change at different rates. Different craniofacial dimensions do not grow at consistent rates. Some parts grow slower compared with others. The intercanthal width has the slowest growth. Facial height shows the fastest growth.

Biometric ratio in estimating widths of maxillary anterior teeth derived after correlating anthropometric measurements with dental measurements.

OBJECTIVE: To correlate dental measurements i.e. combined mesiodistal width of six maxillary anterior teeth with facial measurements i.e. inner canthal distance, interpupillary distance and intercommissural width and acquire a biometric ratio to serve as a preliminary guide in selection of the maxillary anterior teeth. BACKGROUND: In the absence of pre-extraction records, the resultant denture can lead to patient dissatisfaction towards the aesthetic appeal of their dentures. The maxillary anterior teeth play a pivotal role in denture aesthetics. Various techniques and biometric ratios have been described in literature for selection of the maxillary anteriors. This study derives a biometric ratio for the same, obtained after correlating anthropometric measurements with dental measurements. MATERIALS AND METHODS: Two standardized digital photographs of the face were generated; one, when the facial muscles were relaxed and the other, when the subject was smiling; thereby, revealing the maxillary anterior teeth upto the canine tip. Inner canthal distance, interpupillary distance, intercommissural distance, distance between the tips of the maxillary canines and distance between the distal surfaces of the canines were measured. On the cast, the distance between tips of maxillary canines and distance between distal surfaces of maxillary canines were noted. The data was analysed using Spearman's rank correlation coefficient. RESULTS: A high correlation was found between the intercommissural measurement with distance between the tips of the canines on the photograph and between the tips of the canines on the cast with the interpupillary distance, giving a biometric ratio of 1:1.35 and 1:1.41 respectively. The least correlation was between the inner canthal distance and the tips of the canines measured on the photograph. CONCLUSIONS: Extra oral anthropometric measurements of the interpupillary distances and the intercommissural distances with the help of standardised photographs can help us determine the combined widths of the anterior teeth accurately, thus aiding their selection in the absence of pre-extraction records.

Reproducibility of facial soft tissue landmarks on facial images captured on a 3D camera.

OBJECTIVE: Fast and non-invasive systems of the three-dimensional (3D) technology are a recent trend in orthodontics. The reproducibility of facial landmarks is important so that 3D facial measurements are accurate and may-be applied clinically. The aim of this study is to evaluate the reproducibility of facial soft tissue landmarks using a non-invasive stereo-photogrammetry 3D camera. MATERIAL AND METHODS: Twenty-four soft tissue landmarks on 3D facial images captured using a VECTRA-3D dual module camera system for full face imaging (Canfield Scientific inc, Fairfield, NJ, USA) were viewed and analysed using Mirror software on 30 adult subjects (15 males and 15 females, in the age range of 20-25 years). The landmarks were identified, recorded and measured twice on each 3D facial image by one examiner after a 2-week interval. Intra-class correlations and paired t-test or Wilcoxon Rank test were performed for each landmark to assess intra-examiner reproducibility. RESULTS: Intra-class correlation coefficients for all 24 landmarks ranged from 0.68 to 0.97, indicating moderate to high reliability and reproducibility of all facial soft tissue landmarks. Paired t-tests and Wilcoxon Rank test also revealed that there were no significant differences in all 24 facial soft tissue landmarks measurements (p = 0. 17 - 0.99). CONCLUSION: The results indicated that the reproducibility of identification of landmarks by one operator on facial images captured using a VECTRA-3D camera was acceptable. This device may be useful in treatment planning and may provide accurate information in making clinical decisions. However, it is suggested that further studies on inter-examiner reproducibility should be undertaken.

Rehabilitation after surgical treatment for retinoblastoma: ocular prosthesis for a 6-month-old child.

Maxillofacial prosthetic (MFP) rehabilitation can be especially challenging in a young, precooperative, or behaviorally compromised child presenting with an enucleated eye. Retinoblastoma is the most common intraocular malignancy in childhood and is one of the most common pediatric cancers. Treatment consists of enucleation (or removal of the entire globe) followed by placement of orbital implants. Unrestored anopthalmic sockets exhibit growth retardation and can lead to facial disfigurement. This report describes the challenges faced during rehabilitation of a 6-month-old girl with an anophthalmic socket due to enucleation for retinoblastoma. The objective of the MFP team was to provide a custom-built, acrylic ocular prosthesis in as comfortable and atraumatic manner as possible. The case was a success and underscores the value of a multidisciplinary dental approach for the treatment of children with very special needs.

Evaluation of facial anthropometric parameters in 11-17 year old boys.

BACKGROUND AND OBJECTIVE: Anthropometry is the study of qualitative specifications based on linear and angular measurements of human body. The aim of the present study was to determine anthropometric parameters of 11-17 year old boys of northeast Iran. METHOD: This cross-sectional analytical study was conducted on 583 boys of Fars ethnicity living in Mashhad with Class I skeletal and dental relationships. Digital photographs in natural head position were transferred to a computer and the desired anthropometric landmarks were traced on each image. Anthropometric parameters including the width of the forehead, the width of the face, the width of the cranial base, intergonial width, intercanthal width, binocular width, nasal width, mouth width, facial and nasal height and depth of superior, middle and inferior one-third of the face were measured by "Smile Analyzer" software. ANOVA, Tukey test, and linear regression were used for statistical analysis. RESULTS: Most of the parameters studied increased gradually with age. A growth spurt was evident at the ages of 15-16 years old for binocular width, nasal width, nasal height and depths of middle and inferior one-third of the face. Facial height was among some parameters which were found to increase slightly after 16. Unlike the other parameters, intercanthal width showed an irregular pattern of changes and statistical analysis did not show any significant differences among different age groups (P-value = 0.362). CONCLUSION: Aging of the face occurs in spurts and at different periods of life. During the studied time span, significant growth in most anthropometric parameters except intercanthal width was obvious.

A solute gradient in the tear meniscus. I. A hypothesis to explain Marx's line.

Marx's line is a line of mucosal staining behind the mucocutaneous junction. It can be demonstrated throughout life in all normal lids by staining with lissamine green and related dyes. Of all the body orifices, only the mucosae of the eye and mouth are directly exposed to the atmosphere. In this paper, we suggest that for the eye, this exposure leads to the formation of Marx's line. The tear meniscus thins progressively toward its apex, where it is pinned at the mucocutaneous junction of the lid. It also thins toward the black line, which segregates the meniscus from the tear film after the blink. We predict that, because of the geometry of the tear meniscus, evaporation generates a solute gradient across the meniscus profile in the anteroposterior plane, which peaks at the meniscus apices at the end of the interblink. One outcome would be to amplify the level of tear molarity at these sites so that they reach hyperosmolar proportions. Preliminary mathematical modeling suggests that dilution of this effect by advection and diffusion of solute away from the meniscus apex at the mucocutaneous junction will be restricted by spatial constraints, the presence of tear and surface mucins at this site, and limited fluid flow. We conclude that evaporative water loss from the tear meniscus may result in a physiological zone of hyperosmolar and related stresses to the occlusal conjunctiva, directly behind the mucocutaneous junction. We hypothesize that this stimulates a high epithelial cell turnover at this site, incomplete epithelial maturation, and a failure to express key molecules such as MUC 16 and galectin-3, which, with the tight junctions between surface epithelial cells, are necessary to seal the ocular surface and prevent penetration of dyes and other molecules into the epithelium. This is proposed as the basis for Marx's line. In Part II of this paper (also published in this issue of The Ocular Surface), we address additional pathophysiological consequences of this mechanism, affecting lid margins.

Medial canthal region as an external reference point in orthognathic surgery.

PURPOSE: The aim of this investigation was to evaluate the effectiveness of using the medial canthal region (MCR) as an external reference point to determine the vertical dimension during maxillary repositioning as planned in model surgery and predictive tracing. MATERIALS AND METHODS: The analyzed group consisted of 43 consecutive patients who underwent maxillary or bimaxillary orthognathic surgery. Before downfracture, the vertical height was established from the distance of the MCR to the incisal edge of the right upper central incisor (UCI). The vertical dimension was obtained with frequent measurements by use of calipers as desired during cephalometric tracing and model surgery. After rigid fixation, the vertical height was verified again. The UCI was traced from the postoperative cephalogram and predictive tracing onto a preoperative tracing. Repositioning of the maxilla and postsurgical movements of the UCI were registered at the horizontal and vertical planes. Comparison was made between the predicted maxillary position on the cephalometric tracing and the actual position, as well as between the planned maxillary position in model surgery and the actual position. RESULTS: The mean difference between the planned UCI position on predictive tracing and postsurgical position was 0.30 mm (SD, 0.21 mm; P > .05) in the vertical plane. The variation between the planned maxillary position in model surgery and the actual position was 0.37 mm (SD, 0.31 mm; P > .05) in the vertical plane. CONCLUSIONS: Good surgical accuracy in positioning the mobilized maxilla can be achieved by use of the MCR as an external reference point.

Canine tip marker: a simplified tool for measuring intercanine distance.

PURPOSE: Appropriate selection of anterior teeth is considered to be of paramount importance in the success of denture prostheses. This study was undertaken to evaluate the correlation between the intercanthal width and interalar width with intercanine distance, in North Indian male and female patients for predicting the mesiodistal width of the maxillary anterior teeth during tooth selection. MATERIALS AND METHODS: The study was conducted with 100 North Indian patients (50 men, 50 women) ranging in age from 17 to 21 years. A digital caliper with an accuracy of 0.01 mm was used to measure the intercanthal and interalar width. A T-shaped flat metal plate (canine tip marker) was used to mark the intercanine distance, which was then measured with the digital caliper. These measurements were interpreted and subjected to statistical analysis. Student's t-test was applied to test the correlation between intercanthal width and interalar width with intercanine distance. RESULTS: Calculated t-values between intercanine distances with interalar width in both male and female groups were 3.14 and 3.56, respectively, greater than the standard value taken at a 5% level of significance with 48 degree of freedom, showing a higher correlation of interalar width with the intercanine distance. Values obtained between intercanthal width and intercanine distance were lower than the standard value in both groups. CONCLUSIONS: A significant correlation was found between interalar width and intercanine distance in both men and women, suggesting that interalar width can be used as a reliable guide for maxillary anterior teeth selection.

Anatomic properties of the upper eyelid in Asian Americans.

BACKGROUND: With increasing demand for "double eyelid" surgery within the United States, it becomes prudent for U.S. surgeons to become familiar with Asian eyelid anatomy. OBJECTIVE: To identify and describe anatomic characteristics of the Asian upper eyelid. METHODS: A cross-sectional descriptive series of 9 Korean-American and 10 Chinese-American subjects. Standardized photographs of the eyes were analyzed. Three types of eyelid anatomy were described: single eyelid, low eyelid crease, and double eyelid. RESULTS: The incidence rate for the three types of eyelid anatomies varied between Chinese and Korean Americans. The mean palpebral fissure height, width, and inclination were not statistically different between the two populations. A few subjects had asymmetric eyelid configurations. Chinese American and Korean American double eyelids tended to flare up laterally when the eye was open. The mean double eyelid crease height at the medial limbus was 3.7 +/- 1.1 mm, and the mean height at the lateral limbus 4.6 +/- 1.0 mm. This difference was statistically significant (p<.04). CONCLUSION: Eyelid anatomies vary in different Asian Americans. Surgeons need to be mindful of different eyelid configurations and measurement patterns to achieve the most natural-looking Asian double eyelids.

Accuracy and repeatability of cone-beam computed tomography (CBCT) measurements used in the determination of facial indices in the laboratory setup.

AIM: To assess the three dimensional (3D) surface accuracy of a phantom's face acquired from a cone-beam computed tomography (CBCT) scan and to determine the reliability of selected cephalometric measurements performed with Maxilim software (Medicim N.V., Mechelen, Belgium). MATERIAL AND METHODS: A mannequin head was imaged with a CBCT (I-CAT, Imaging Sciences International, Inc., Hatfield, USA). The data were used to produce 3D surface meshes (Maxilim and Mimics, Materialise N.V., Leuven, Belgium) which were compared with an optical surface scan of the head using Focus Inspection software (Metris N.V., Leuven, Belgium). The intra- and inter-observer reliability for the measurement of distances between facial landmarks with Maxilim 3D cephalometry were determined by calculating Pearson correlation coefficients and intraclass correlation (ICC). The Dahlberg formula was used to assess the method error (ME). RESULTS: (1) The maximal range of the 3D mesh deviations was 1.9 mm for Maxilim, and 1.8mm for Mimics segmentation. (2) Test-retest and inter-observer reliability were high; Pearson's correlation coefficient was 1.000 and the ICC was 0.9998. The ME of the vertical measurements was a little larger than that calculated for the width measurements. Maximum ME was 1.33 mm. CONCLUSIONS: The 3D surface accuracy of CBCT scans segmented with Maxilim and Mimics software is high. Maxilim also shows satisfactory intra- and inter-assessor reliability for measurement of distances on a rigid facial surface.

Lip posture following debonding of labial appliances based on conventional profile photographs.

OBJECTIVE: To assess changes in lip posture following debonding of labial appliances on the basis of a new soft tissue analysis performed by computerized tools with the use of conventional nonstandardized profile photographic pictures. MATERIALS AND METHODS: Profile photographs of 33 patients were taken just before and just after debonding of labial brackets. Pictures were examined twice through custom-made analysis in which Viewbox software was used. The validity of this new analysis was assessed in a preliminary study. A reference line was constructed between the center of the tragus and the outer canthus. The point where this elongated line intersected with the profile was coined nasion-modified and served as the vertex point for angles used to evaluate the prominence of the lips. The final position of the lines was determined when they were tangent to the appropriate landmarks. Analysis of variance (ANOVA) and t-tests for paired differences were used. RESULTS: The reproducibility of this photoanalysis was confirmed in the preliminary study, in that no significant differences were found between measurements (P < .05). No statistically significant differences were noted in lip posture between pre-debonding and post-debonding pictures (P < .05). CONCLUSIONS: In keeping with the design of this study, soft tissue profile photoanalysis showed that the presence of bonded labial appliances had no effect on lip posture.

Towards building a photo-realistic virtual human face for craniomaxillofacial diagnosis and treatment planning.

The aim of this investigation was to assess the feasibility of building a virtual human face digitally by superimposing a photo-realistic three-dimensional (3D) soft-tissue surface on bone in the correct relationship and evaluating the registration errors associated with this method. The 3D soft-tissue surface of the face was captured using a fast stereophotogrammetry method and the underlying bone was recorded using a 3D computed tomography (CT) scanner. Using the Procrustes registration method, the outer surface of the 3D CT scan and the photo-realistic soft-tissue surfaces were merged into a single Virtual Reality Modelling Language (VRML) file and displayed using a standard VRML viewer. Quantitative measurements of registration errors were calculated in the reconstructed human head models using the signed closest point distance from the photo-realistic skin surface to the transformed CT skin surface. The registration errors between most parts of the aligned surfaces were within +/-1.5mm. The errors were relatively large around the eyebrows, eyelids and cheeks. Simultaneous recording of the face and skull may reduce this error.