The "Central Tendency Bias" in the assessment of facial attractiveness in group-based and individual ratings-A survey-based study in 727 volunteers.

BACKGROUND: The increasing number of esthetic procedures emphasizes the need for effective evaluation methods of outcomes. Current practices include the individual practitioners' judgment in conjunction with standardized scales, often relying on the comparison of before and after photographs. This study investigates whether comparative evaluations influence the perception of beauty and aims to enhance the accuracy of esthetic assessments in clinical and research settings. OBJECTIVE: To compare the evaluation of attractiveness and gender characteristics of faces in group-based versus individual ratings. METHODS: A sample of 727 volunteers (average age of 29.5 years) assessed 40 facial photographs (20 male, 20 female) for attractiveness, masculinity, and femininity using a 5-point Likert scale. Each face was digitally edited to display varying ratios in four lip-related proportions: vertical lip position, lip width, upper lip esthetics, and lower lip esthetics. Participants rated these images both in an image series (group-based) and individually. RESULTS: Differences in the perception of the most attractive/masculine/feminine ratios for each lip proportion were found in both the group-based and individual ratings. Group ratings exhibited a significant central tendency bias, with a preference for more average outcomes compared with individual ratings, with an average difference of 0.50 versus 1.00. (p = 0.033) CONCLUSION: A central tendency bias was noted in evaluations of attractiveness, masculinity, and femininity in group-based image presentation, indicating a bias toward more "average" features. Conversely, individual assessments displayed a preference for more pronounced, "non-average" appearances, thereby possibly pointing toward a malleable "intrinsic esthetic blueprint" shaped by comparative context.

The reliability of analytical reference lines for determining esthetically pleasing lip position: An assessment of consistency, sensitivity, and specificity.

INTRODUCTION: This study aimed to identify a simple yet reliable soft-tissue parameter for the clinical determination of esthetic lip position by investigating the most consistent reference lines and assessing their sensitivity and specificity. METHODS: A total of 5745 records from Chinese patients aged >18 years were screened. In part I of the study, lateral view photographs of 96 subjects (33 males, 63 females) with esthetic facial profiles were selected. The profile esthetics of each photograph was first scored by 52 dental students, followed by 97 laypeople on a 5-point attractiveness scale. For the top 25% of photographs with the highest score for each sex (8 males, 16 females), the consistency of 6 commonly used reference lines were assessed to determine the esthetic lip position. In part II of the study, lip positions relative to Steiner's (S) and Ricketts' (E) lines in the profile photographs of 86 patients (43 males, 43 females) deemed to have an esthetically unpleasing profile were compared with those in 86 Chinese movie star idols (43 males, 43 females). RESULTS: In part I of the study, the S, E, and Burstone's (B) lines exhibited the lowest standard deviations for the upper and lower lips. B line was excluded from further analysis because of its higher mean absolute values, and S and E lines were used for the subjective assessment in part II of the study. In part II, the S line showed a sensitivity of 86.0% and 86.0% and a specificity of 81.4% and 83.7% for males and females, respectively. In contrast, the E line presented a sensitivity of 88.4% and 93.0% and a specificity of 79.1% and 74.4% for males and females, respectively. CONCLUSIONS: S, E, and B lines were the most consistent soft-tissue parameters among both sexes; however, because of the smaller absolute values, the S line would be more convenient among the 3 for a quick clinical assessment of lip position. Moreover, the performance of both S and E lines was similar among both sexes, which supports using these lines in assessing the esthetic lip position.

Assessment of Ideal Dimensions of the Ears, Nose, and Lip in the Circles of Prominence Theory on Facial Beauty.

IMPORTANCE: A theory on facial beauty might allow clinicians to achieve better results. OBJECTIVES: To find the ideal vertical position of the ears, total lip length, lip pucker length, distance between the irises, and starting point for the nasal radix. DESIGN, SETTING, AND PARTICIPANTS: In this subjective survey, 11 sets of 43 total digitally adjusted pictures (DAPs) and line drawings of actual faces were ranked based on attractiveness by 419 clients at a facial plastic surgery clinic. The data were collected from July 13 to August 29, 2015, and were analyzed from September 17, 2015, to March 21, 2016. MAIN OUTCOMES AND MEASURE: Six groups of line drawings and 5 groups of DAPs of an actual person were used to test the ideal position of the ears to determine whether the face is organized into oblique and parallel relationships and whether the total lip length and the lip pucker length are associated with multiples of an iris width (IW), and to determine the start of the nasal radix and its association with the superior margin of the iris and distance between the irises. RESULTS: Of the 419 survey respondents, the ear aligned with the second oblique was considered the most ideal by the participants. The preferred total lip length was 4.0 IWs in the DAPs and 5.0 IWs in the line drawings. For the lip pucker length, 2.0 and 3.0 IWs were considered the best. The ideal start of the nasal radix was tangential with the superior margin of the iris. The distance of 5.5 IWs from iris to iris and 3.0 IWs from the horizontal level of the iris to the nasal tip was preferred. CONCLUSIONS AND RELEVANCE: The face may be ideally organized into 3 parallel obliques. The IW, horizontal aperture of the eye, and then iris to iris distance may best determine the size and shape of progressively larger objects in the face. The absolute position of the eye was considered important by the participants in the ideal positioning of other objects in the face. LEVEL OF EVIDENCE: NA.

Reliability of Americleft Yardstick Nasolabial Appearance Assessment With/Without Basal View for Japanese Children With Unilateral Complete Cleft Lip and Palate.

OBJECTIVE: There is debate on the reliability of the Americleft Yardstick (AY) global nasolabial appearance assessment method. The objective was to analyze the effect of the additional basal view (BV) feature on the reliability of the AY method for Japanese children with complete cleft lip and palate (CUCLP). DESIGN: Blind retrospective analysis of clinical records on 43 patients (5- to 7-year-old) with nonsyndromic CUCLP who underwent primary lip repair from 2005 to 2011. MAIN OUTCOME MEASURE: Color pictures published in AY and Rubin's studies were used as reference pictures. Patients' photographs were cropped and rated on a 5-point scale for the vermilion border (VB), nasolabial frontal (NLF), and nasolabial profile (NLP) according to AY with/without BV assessment by Rubin's methods. Rating was performed twice by 3 oral surgeons. Intra- and inter-rater reliabilities were analyzed using weighted κ, and correlations between BV and other features were analyzed. RESULTS: Overall average assessment scores were 2.742 (0.573) with AY and 2.702 (0.489) with AY+BV methods (P = .728). Average intra-rater reliabilities were 0.605 and 0.611 and average inter-rater reliabilities were 0.525 and 0.48 with AY and AY+BV, respectively. Inter-rater reliability was the lowest for NLP. ρ scores between BV versus VB, NLF, and NLP were 0.025, 0.659, and 0.092, respectively. CONCLUSIONS: Present study demonstrates moderate intra- and inter-rater reliabilities obtained with the AY assessment method for Japanese children with CUCLP. Nasolabial profile standard ambiguity may lead to the poor reliability of AY assessment. Addition of the BV feature does not improve overall reliability.

Assessment of regional asymmetry of the face before and after surgical correction of unilateral cleft lip.

This study was carried out on 26 unilateral cleft lip and palate (UCLP) cases with mean age 3.6 ± 0.7 months.3D facial images were captured for each infant 2-3 days before the repair of cleft lip and at 4 months following surgery at a mean age of 8.2 ± 1.8 months, using a stereophotogrammetry imaging system. An iterative closest point (ICP) algorithm was used to superimpose the 3D facial model to its mirror image using VRMesh software. After the superimposition, the face model was divided into seven anatomical regions. Asymmetry of the entire face and of the anatomical regions was calculated by measuring the absolute distances between the 3D facial surface model and its mirror image. Colour maps were used to illustrate the patterns and magnitude of the facial asymmetry before and after surgery. There were significant decreases in the asymmetry scores for the nose, upper lip and the cheeks as a result of the surgical repair of cleft lips. Surgery did not change the magnitude of the asymmetry scores for the lower lip and chin. Residual nasolabial asymmetries were detected. The main outcome of the findings of this innovative study is to inform the required surgical refinement of primary repair of cleft lip in order to minimise facial asymmetry. We have presented a sensitive tool that could be used for comparative analysis of lip repair at various cleft centres and to guide secondary corrective surgery when required.

The Lip-Tooth-Ridge Classification: A Guidepost for Edentulous Maxillary Arches. Diagnosis, Risk Assessment, and Implant Treatment Indications.

Prosthetic rehabilitation of the edentulous maxilla is known to be challenging and requires meticulous planning. The purpose of this article is to describe a novel classification system, the Lip-Tooth-Ridge (LTR), that offers a guidepost for treatment planning the edentulous maxilla for fixed or removable prostheses. This tool will help clinicians identify the final prosthetic design and will provide a case-specific risk assessment guide regarding two different areas. A high (HER) or low (LER) esthetic risk will be determined based on lip dynamics, as well as a high or low structural risk according to the prosthetic space availability.

Direct Anthropometry of Repaired Bilateral Complete Cleft Lip: A Long-Term Assessment.

BACKGROUND: Repair of bilateral complete cleft lip requires more than following a design in a textbook. The operative strategy should incorporate knowledge of anticipated nasolabial changes with growth. METHODS: Direct nasolabial anthropometry was recorded in 174 children with bilateral complete cleft lip before and immediately after primary repair. Serial measurements were taken in 66 Caucasian patients between the ages of 6 months and 15 years and compared to Farkas' normal values. Data for upper philtral width were unavailable; therefore, this dimension was measured in 454 nonsyndromic Caucasian male and female subjects aged 1 year to adulthood. Rates and types of revision were also documented. RESULTS: Inter-medial canthal width stayed above the mean and within normal limits throughout puberty. Interalar width was initially narrowed and hovered in the high normal range throughout adolescence. Columellar height and nasal projection were constructed slightly long and paralleled normal growth. Available cutaneous philtral length was used in the primary repair; however, this dimension remained short. The philtrum was made narrow and matched normal values throughout adolescence. Normal inferior/superior philtral width ratio was 1.60 for female subjects and 1.59 for male subjects. A full median tubercle was built at primary repair but, sometimes in late childhood, necessitated secondary augmentation with a dermal graft in 31 of 174 patients (18 percent), usually performed in late childhood or adolescence. CONCLUSIONS: Serial anthropometry documented postoperative changes in nasolabial dimensions compared to normal growth curves. Repair of bilateral complete cleft lip requires primary correction of nasal and labial features based on their differential growth, with special attention to nasal width, philtral height and proportions, and size of the median tubercle. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Comparison of two- and three-dimensional assessment methods of nasolabial appearance in cleft lip and palate patients: Do the assessment methods measure the same outcome?

OBJECTIVE: For the assessment of the nasolabial appearance in cleft patients, a widely accepted, reliable scoring system is not available. In this study four different methods of assessment are compared, including 2D and 3D asymmetry and aesthetic assessments. METHODS: The data and ratings from an earlier study using the Asher-McDade aesthetic index on 3D photographs and the outcomes of 3D facial distance mapping were compared to a 2D aesthetic assessment, the Cleft Aesthetic Rating Scale, and to SymNose, a computerized 2D asymmetry assessment technique. The reliability and correlation between the four assessment techniques were tested using a sample of 79 patients. RESULTS: The 3D asymmetry assessment had the highest reliability and could be performed by just one observer (Intraclass correlation coefficient (ICC): 0.99). The 2D asymmetry assessment of the nose was highly reliable when performed by just one observer (ICC: 0.89). However, for the 2D asymmetry assessment of the lip more observers were needed. For the 2D aesthetic assessments 3 observers were needed. The 3D aesthetic assessment had the lowest single-observer reliability (ICC: 0.38-0.56) of all four techniques. The agreement between the different assessment methods is poor to very poor. The highest correlation (R: 0.48) was found between 2D and 3D aesthetic assessments. Remarkably, the lowest correlations were found between 2D and 3D asymmetry assessments (0.08-0.17). CONCLUSION: Different assessment methods are not in agreement and seem to measure different nasolabial aspects. More research is needed to establish exactly what each assessment technique measures and which measurements or outcomes are relevant for the patients.

Influence of lip retraction on the cone beam computed tomography assessment of bone and gingival tissues of the anterior maxilla.

OBJECTIVE: To evaluate the influence of lip retraction on cone beam computed tomography (CBCT) assessment of bone and gingival tissues on the labial surface of the anterior maxilla. STUDY DESIGN: A retrospective study was conducted using measurements of bone and gingival tissues collected from 120 maxillary incisors. The thicknesses of the bone and gingival tissues of different regions were measured on CBCT images, with and without a lip retractor. The thicknesses of the gingival tissues obtained from CBCT were correlated with measurements performed by clinical probing. RESULTS: The thickness of bone in the more cervical region presented a higher mean value for exams performed with a lip retractor (P = .021). The thickness of bone found a significant correlation with the thickness of the gingiva (P ≤ .020) with a lip retractor in CBCT exams. The thickness of the gingival tissue obtained from CBCT scans with lip retraction found significant correlations with those obtained clinically (P ≤ .001). CONCLUSIONS: The use of lip retractors is a simple and reliable practice that allows the measurement of gingival tissues on CBCT images. This practice can exempt a patient from an invasive clinical procedure for measuring the thickness of the gingival tissue for implant cases of the anterior segment.

Assessment of gingival biotype and facial hard/soft tissue dimensions in the maxillary anterior teeth region using cone beam computed tomography.

OBJECTIVE: This study sought to assess the relationship between facial gingival and bone dimensions in maxillary anterior teeth region using cone beam computed tomography (CBCT). DESIGN: This study assessed 621 maxillary anterior teeth in 144 patients. In the sagittal plane, facial bone thickness (BT) and gingival thickness (GT) were measured at the crestal level and at 2, 4 and 6mm apical to the cementoenamel junction (CEJ). The dentogingival complex (DGC) dimensions and the distance from the CEJ to bone crest were also measured on CBCT scans. To determine the gingival biotype, GT at 2mm apical to the gingival margin was measured and GT <1.5mm was categorized as thin while GT ≥1.5mm was categorized as thick. The data were analyzed using SPSS version 21 via repeated measures ANOVA and the Cochrane's Q, chi-square and independent samples t-tests. RESULTS: The BT around the maxillary central and lateral incisors and canine teeth at 4 and 6mm apical to the CEJ was significantly different in thick and thin gingival biotypes (P<0.05). The mean GT at 2 and 4mm apical to the CEJ was significantly different around central and lateral incisors (P<0.05). Thickness of crestal bone was significantly different between the two gingival biotypes around central and lateral incisors (P<0.05). CONCLUSION: The two gingival biotypes had significantly different mean BT; different biotypes and their relationship to BT varied around anterior maxillary teeth.

Facial Aesthetic Outcomes of Cleft Surgery: Assessment of Discrete Lip and Nose Images Compared with Digital Symmetry Analysis.

BACKGROUND: High-quality aesthetic outcomes are of paramount importance to children growing up after cleft lip and palate surgery. Establishing a validated and reliable assessment tool for cleft professionals and families will facilitate cleft units, surgeons, techniques, and protocols to be audited and compared with greater confidence. This study used exemplar images across a five-point aesthetic scale, identified in a pilot project, to score lips and noses as separate units and compared these human scores with computer-based SymNose symmetry scores. METHODS: Forty-five assessors (17 cleft surgeons nationally and 28 other cleft professionals from the UK South West Tri-centre units), scored 25 standardized photographs, uploaded randomly onto a Web-based platform, twice. Each photograph was shown in three forms: lip and nose together, and separately cropped images of nose only and lip only. The same images were analyzed using the SymNose software program. RESULTS: Scoring lips gave the best intrarater and interrater reliabilities. Nose scores were more variable. Lip scoring associated most closely with the whole-image score. SymNose ranking of the lip images related highly to the same ranking by humans (p = 0.001). The exemplar images maintained their established previous ranking. CONCLUSIONS: Images illustrating the aesthetic outcome grades are confirmed. The lip score is reliable and seems to dominate in the whole-image score. Noses are much harder to score reliably. It appears that SymNose can score lip images very effectively by symmetry. Further use of SymNose will be investigated, and families of children with cleft will trial the scoring system. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

Development and validation of a photographic scale for assessment of lip fullness.

BACKGROUND: As lip augmentation becomes more popular, validated measures of lip fullness for quantification of outcomes are needed. OBJECTIVE: Develop a scale for rating lip fullness and establish its reliability and sensitivity for assessing clinically meaningful differences. METHODS: The initial Allergan Lip Fullness Scale (iLFS; a four-point photographic scale with verbal descriptions) was validated by eight physicians rating 55 live subjects during two rounds, conducted on one day. In addition, subjects performed self-evaluations. The revised Allergan Lip Fullness Scale (LFS), a five-point scale with a broader range of lip presentations, was validated by 21 clinicians in two online image rating sessions, ≥14 days apart, in which they used the LFS to rate overall, upper, and lower lip fullness of 144 3-dimensional (3D) images. Physician inter- and intra-rater agreement, subject intra-rater agreement (iLFS), and subject-physician agreement (iLFS) were evaluated. Additionally, during online rating session 1, raters ranked 38 pairs of 3D images, taken before and after lip augmentation, as "clinically different" or "not clinically different." The median LFS score difference for clinically different pairs was calculated to determine the clinically meaningful difference. RESULTS: Clinician inter- and intra-rater agreement for the iLFS and LFS was substantial to almost perfect. Subject self-assessments (iLFS) had substantial intra-rater reliability and a high level of agreement with physician assessments. Median LFS score differences for overall, upper, and lower lip fullness were 1 (mean: 0.63-0.69) for "clinically different" and 0 (mean: 0.28-0.36) for "not clinically different" image pairs; thus, clinical significance of a 1-point difference in LFS score was established. CONCLUSIONS: The LFS is a reliable instrument for physician classification of lip fullness. A 1-point score difference can detect clinically meaningful differences in lip fullness.

Socio-economic indicators and predisposing factors associated with traumatic dental injuries in schoolchildren at Brasília, Brazil: a cross-sectional, population-based study.

BACKGROUND: This study assessed the prevalence of traumatic dental injuries (TDI) and its association with sociodemographic and physical characteristics in the anterior permanent teeth of 12-year-old schoolchildren at the city of Brasília - DF, Brazil. METHODS: A cross-sectional, population-based study was conducted on a sample of 1,389 boys and girls aged 12 years, enrolled in public and private fundamental schools at the Administrative Region (RA) of Brasília, Brazil, from October 2011 to September 2012. The demographic details were achieved by a structured questionnaire. The study recorded the type of damage, the size of incisal overjet, and whether lip coverage was inadequate. Sociodemographic data included sex, income and educational level of the parents or caretakers. RESULTS: A total of 1118 schoolchildren were examined, yielding a response rate of 80.48%. The prevalence of TDI was 14.63% in public schools and 23.40% in private schools. The students did not differ according to sex, income and educational level of the parents or caretakers concerning the occurrence of traumas in permanent anterior teeth. Increased overjet and inadequate lip coverage were found to be important contributing factors for TDIs. CONCLUSION: In conclusion, this study showed an expressive prevalence of TDI in 12-year-old in schoolchildren at Brasília DF, Brazil. Sex and educational level of the parents were not associated with trauma. The increased overjet and inadequate lip coverage were significantly associated with dental trauma.

Photos vs silhouettes for evaluation of profile esthetics between white and black evaluators.

OBJECTIVE: To determine whether photos or silhouettes are adequate methods for evaluating the esthetic profiles of black subjects and whether black and white evaluators have different preferences for esthetic profiles. MATERIALS AND METHODS: One photographic record of the profile of a black female patient with accentuated dental bimaxillary dentoalveolar protrusion was randomly selected. The image of the patient's profile was altered to produce a series of seven photos and seven silhouettes (a total of 14 images) with different lip positions but uniform distances in relation to the esthetic plane created by Ricketts (line E). Fifty black and 50 white lay evaluators were invited to enumerate the photos and silhouettes, produced according to the lip position, in the order in which they considered most esthetically pleasing. RESULTS: The number of preferences found to be within the esthetic norm was slightly higher among the photographs than among the silhouettes; the esthetic profile with a deviation of -2 mm from line E was elected as the most attractive, and the esthetic pattern with a deviation of +6 mm from the normal line E was considered the least attractive. There were no statistically significant differences between the preferences related to the variables race, sex, and educational background. CONCLUSIONS: The esthetic attractiveness of the facial profiles of black subjects in photos and silhouettes was evaluated in a similar manner among black and white evaluators. Among both black and white evaluators, the greatest preference was for the slightly concave profile, which was within the limit considered standard.

Assessment of lip position preferences in a Saudi population using computer imaging.

This study aimed to evaluate the perception of lip position preferences in a Saudi population and compare it to the perception of other populations. Master pictures of a male and female Saudi model were prepared with the upper lip 3 mm from Ricketts' E-line and the lower lip 1 mm behind. The lip position was then altered using computer imaging to create a range of pictures from the upper lip 15 mm behind the E-line to the upper lip 6 mm beyond the E-line. One hundred and fifty-six individuals (60 male, 96 female) were asked to rate the pictures in terms of acceptability and also which picture they liked best. The preferences were compared based on gender, perception of their own lateral profile and history of previous orthodontic treatment. The study found that regardless of gender, the Saudi population has a distinct preference for lip positions that are further away from the E-line than the current Western standard. The population studied also showed a greater tolerance for deviation in the lip position away from the E-line than deviations towards the E-line.

Assessment of the perception of smile esthetics by laypersons, dental students and dental practitioners.

UNLABELLED: The aim of this study was to determine the esthetic perception of some components of the smile such as gingival exposure, level of the gingival margins, length of the crowns, maxillary midline and inter-incisor diastema by laypersons, dental students and dental professionals. MATERIALS AND METHODS: Six hundred and thirty-four Portuguese people (292 laypersons, 241 dental students and 101 practitioners) assessed the esthetics of 13 altered pictures of the same smile arranged at random. The manipulated components (gingival exposure, level of the gingival margins, length of the crowns, maxillary midline and inter-incisor diastema) were altered using Adobe Photoshop® CS6 software. The classification of the pictures was done using the visual analogue scale (VAS), scored 1 to 10. The responses were then analyzed and processed with SPSS® version 21.0 using tests of average equality and correlation. RESULTS: The medium smile was the most appreciated smile, whereas the high smile and diastemas were considered to be the least esthetic. Among all the modified parameters, the midline shift was the least perceptible. The preference for asymmetry of the gingival margin at the maxillary lateral incisors (MLI) and the symmetry in the length of the crowns of the maxillary central incisors (MCI) reflected the importance given to MCI during smiling. Gender did not influence the scores given, except for gummy smiles, while younger people gave the highest scores. Regarding academic/professional training, there was an intra-group homogeneity of opinions as laypersons tended to give higher scores and professionals tended to give lower scores, but with no correlation between the variables. The fact that the laypersons had received orthodontic treatment, or not, had no influence on their perception. CONCLUSIONS: Laypersons, dental students and dental professionals had different perceptions of attractiveness when evaluating different modified features, except for diastemas, but with no significant differences between them. Gender was correlated with a very high smile. Age did not correlate with the judgment of the evaluators. There was no difference between the perceptions of laypersons, whether they had received orthodontic treatment or not.

Esthetic smile preferences and the orientation of the maxillary occlusal plane.

STATEMENT OF PROBLEM: The anteroposterior orientation of the maxillary occlusal plane has an important role in the creation, assessment, and perception of an esthetic smile. However, the effect of the angle at which this plane is visualized (the viewing angle) in a broad smile has not been quantified. PURPOSE: The purpose of this study was to assess the esthetic preferences of dental professionals and nondentists by using 3 viewing angles of the anteroposterior orientation of the maxillary occlusal plane. MATERIAL AND METHODS: After Institutional Review Board approval, standardized digital photographic images of the smiles of 100 participants were recorded by simultaneously triggering 3 cameras set at different viewing angles. The top camera was positioned 10 degrees above the occlusal plane (camera #1, Top view); the center camera was positioned at the level of the occlusal plane (camera #2, Center view); and the bottom camera was located 10 degrees below the occlusal plane (camera #3, Bottom view). Forty-two dental professionals and 31 nondentists (persons from the general population) independently evaluated digital images of each participant's smile captured from the Top view, Center view, and Bottom view. The 73 evaluators were asked individually through a questionnaire to rank the 3 photographic images of each patient as 'most pleasing,' 'somewhat pleasing,' or 'least pleasing,' with most pleasing being the most esthetic view and the preferred orientation of the occlusal plane. The resulting esthetic preferences were statistically analyzed by using the Friedman test. In addition, the participants were asked to rank their own images from the 3 viewing angles as 'most pleasing,' 'somewhat pleasing,' and 'least pleasing.' RESULTS: The 73 evaluators found statistically significant differences in the esthetic preferences between the Top and Bottom views and between the Center and Bottom views (P<.001). No significant differences were found between the Top and Center views. The Top position was marginally preferred over the Center, and both were significantly preferred over the Bottom position. When the participants evaluated their own smiles, a significantly greater number (P< .001) preferred the Top view over the Center or the Bottom views. No significant differences were found in preferences based on the demographics of the evaluators when comparing age, education, gender, profession, and race. CONCLUSIONS: The esthetic preference for the maxillary occlusal plane was influenced by the viewing angle with the higher (Top) and center views preferred by both dental and nondental evaluators. The participants themselves preferred the higher view of their smile significantly more often than the center or lower angle views (P<.001).

Assessment of lower lip changes following incisor displacement in 92 orthodontically-treated adults.

AIM: A retrospective assessment of the lower lip changes consequent to incisor displacement in correction of malocclusion in a sample of 92 post-adolescent subjects. METHODS: The study sample comprised two groups, subdivided according to the direction of incisor movement achieved during orthodontic treatment: the retraction group (Group 1), made up of 41 patients in which the maxillary incisor had been moved in a palatal direction (palatal tipping); and the protraction group (Group 2), composed of 51 patients who had undergone labial movement of the upper incisors (labial tipping). In order to evaluate the mean changes in lower lip position, and consequent alterations in the quality of the patients' profiles, between T1 (prior to orthodontic displacement of the incisors) and T2 (following treatment), the following parameters were measured on lateral head film X rays: variation in lower lip vermilion thickness (dLVT); variation in lower lip sulcus depth (dLLSD); variation in lower vermilion height (dLVH); variation in exposure of the upper and lower incisors in relation to the lower stomion (dIs-STOi and dIi-STOi, respectively); variation in upper and lower incisor tipping with respect to the palatal plane (d1/PP and dinf1/PP); and variation in lower facial height (dLFH). RESULTS: Assessment of the changes due to incisor translocation revealed significant differences between Group 1 and Group 2 in all lower lip soft tissue parameters, except for dLVT, dLVH and dIi-STOi. Furthermore, using multiple linear regression analysis to predict the behaviour of the dependent (cutaneous) lower lip variables, a good coefficient of determination (r-square) value was only obtained for the horizontal variation of the labrale inferius point (dxLi), found to be dependent on horizontal movement of the upper and lower incisors (dxIs and dxIi) and thickness of the lower vermilion (LVT). CONCLUSIONS: The results of this study highlight great variability among the patients studied, and suggest that the behaviour of the soft tissues (lower lip changes) following displacement of the upper and lower incisors is multifactorial and very difficult to predict.

Assessment of a method for the automatic on/off control of an electrolarynx via lip deformation.

OBJECTIVES: To reduce the inconvenience caused by operating a button-electrolarynx (EL) by hand, we proposed a method for the automatic control of an EL via lip deformation and applied the method to a video-based experimental system (video-EL). The purpose of this study was to validate the method and assess its performance in producing Mandarin Chinese. STUDY DESIGN AND METHODS: Eight subjects, including one laryngectomee, were invited to participate in the assessment. First, the empirical parameters of phonation onset/offset estimation were compared with the optimal parameters obtained by minimizing simulation errors during video-EL. Second, a reaction time test was used to evaluate the ability of subjects to pronounce a single word with video-EL. Third, the fluency of subjects in producing long sentences with video-EL was calculated. Finally, the intelligibility of speech produced with video-EL was compared with that produced with button-EL. RESULTS: The empirical parameters were not significantly different from the optimal parameter and resulted in fewer interruptions during voicing. Video-EL resulted in slower voice initiation and termination when compared with button-EL, which affected the intelligibility of an isolated word. However, video-EL provided a sufficiently fluent voice source so that the intelligibility of speech produced with video-EL was not significantly different from speech produced with button-EL when producing sentences. CONCLUSIONS: The method proposed in this study is effective in the automatic on/off control of an EL. Subjects produced fluent speech with video-EL that was as intelligible as that produced with button-EL when Mandarin sentences were produced continuously.