Quantitative investigation of the esthetic impact of lip prominence in relation to the esthetic line.

INTRODUCTION: The purpose of this quantitative investigation was to assess the influence of lip prominence in relation to the esthetic line (E-line) on perceived attractiveness and threshold values of desire for treatment. METHODS: The lip prominence of an idealized silhouette male white profile image was altered incrementally between -16 mm to 4 mm from the E-line. The images were rated on a Likert scale by pretreatment orthognathic patients (n = 75), laypeople (n = 75), and clinicians (n = 35). RESULTS: In terms of perceived attractiveness, lips to E-line distance within the ranges of -12 mm to -16 mm and 0-4 mm in relation to the E-line was associated with a reduction in median attractiveness scores to below 4 in the patient and clinician groups of observers; for the lay group, the corresponding ranges were -14 mm to -16 mm and 2-4 mm. Relative lip prominence appears to be viewed as more attractive than lip retrusion. Clinicians were generally least likely to suggest treatment for varying levels of bilabial position. For a number of the images, there was reasonable agreement among clinicians and laypeople regarding whether treatment is required. For the clinician group, the only categories for desire for treatment were at a lip to E-line distance within the ranges of -14 mm to -16 mm and 2-4 mm. CONCLUSIONS: It is recommended that the range of normal variability of the prominence of the lips and threshold values of the desire for treatment be considered in planning.

Root Pulp Visibility as a mandibular maturity marker at the 18-year threshold in the Maltese population.

INTRODUCTION: The determination of age of majority (the 18-year-old threshold) using the popular Demirjian tooth staging method is unreliable, so other maturity markers are required. This study examines whether the Root Pulp Visibility (RPV) of the mandibular third molar is a useful indicator of age. METHODS: One thousand six dental panoramic radiographs (DPTs) were examined and the left mandibular third molar assessed according to the RPV stages using the method of Olze et al. (Int J Legal Med 124:183-186, 2010) as modified by Lucas et al. (Forensic Sci Int 270:98-102, 2017). Six hundred sixty-two DPTs, 288 males and 374 females, satisfied the inclusion criteria. RESULTS: Individuals who had reached stages RPV-A and RPV-B were represented in a wide range of ages spanning the 18-year-old threshold. Individuals who had reached stages RPV-C and RPV-D were all above the 18-year-old threshold. It was not possible to analyse a large number of DPTs for various reasons. DISCUSSION: Individuals whose mandibular third molar exhibited stages RPV-C and RPV-D may be deemed to have reached the age of majority. These results are consistent with other published studies. Variation in the rate of development of the third molar limits the applicability of this method. CONCLUSIONS: RPV staging is an accurate method of determining the 18-year-old threshold. Substitute methods are required in a large number of cases.

The Opinion of Different Observer Groups About the Esthetic Impact and Need for Surgical Correction of Varying Submental Lengths.

PURPOSE: This study evaluated the opinion of different observer groups about the influence of the submental length on perceived attractiveness and when surgical correction was deemed necessary. MATERIALS AND METHODS: The submental length of an idealized silhouette of a white male profile was altered incrementally between 5 and 95 mm. Images were rated for attractiveness on a Likert scale by pretreatment orthognathic surgery patients (n = 75), laypersons (n = 75), and clinicians (maxillofacial surgeons and orthodontists) (n = 35). RESULTS: For perceived attractiveness, the ideal submental length was approximately 50 mm (range, 40 to 75 mm). A submental length shorter than or equal to 30 mm was deemed unattractive by all 3 groups. Overall, a submental length less than 40 mm generally was judged less attractive than a comparable increase in length. Clinicians were generally least likely to suggest surgery for varying submental lengths. For this group, the cutoff at which the majority suggested surgery was a submental length of 25 mm or less. For the patient and layperson groups, the corresponding cutoff values were a length shorter than or equal to 30 mm or equal to 95 mm. CONCLUSIONS: A submental length of approximately 50 mm (range, 40 to 75 mm) was viewed by most observers as attractive. At 30 mm or less, it was generally deemed progressively less attractive. Clinicians were less likely to suggest corrective surgery than were the patient and layperson groups. For comparative proportional relationships, the submental length should be between the lower lip-chin height and lower facial height, assuming an otherwise proportional facial profile.

Patients with cleft: Experiences, understanding and information provision during treatment.

OBJECTIVE: To explore the knowledge of late adolescent and adults affected with cleft lip and/or palate (CL/P) about their condition and their experiences with information about treatment options and outcomes within the cleft care pathway. SETTING AND SAMPLE POPULATION: Twenty-eight people with CL/P had recently finished or were about to finish their definitive orthodontic/orthognathic (OGN) treatment. Participants were purposively recruited from two cleft centres in the UK. MATERIALS AND METHODS: Qualitative, semi-structured interviews were conducted and all interviews were recorded and transcribed verbatim. Thematic analysis was undertaken using the framework method. RESULT: There are a broad range of interpretations and explanations for both the causes and implications of CL/P amongst those living with the condition. This resulted in confusion and left participants vulnerable to misinformation and unable to combat stigma. In addition, there was some confusion about the implication of different treatment options. Participants felt that they did not receive enough information about the nature of the treatment that they would be undergoing and the length and implications of recovery post-treatment. This was a source of concern for the participants. CONCLUSION: The findings of this study suggest that there is a mismatch between the information provided to the families of people with CL/P and the levels of knowledge they have, about both their condition and the treatment options available to them. It is essential that clear, accessible information is provided at the right times in the care pathway to ensure that patients are able to make informed decisions about treatment.

Examining Cardiomyocyte Dysfunction Using Acute Chemical Induction of an Ageing Phenotype.

Much effort is focussed on understanding the structural and functional changes in the heart that underlie age-dependent deterioration of cardiac performance. Longitudinal studies, using aged animals, have pinpointed changes occurring to the contractile myocytes within the heart. However, whilst longitudinal studies are important, other experimental approaches are being advanced that can recapitulate the phenotypic changes seen during ageing. This study investigated the induction of an ageing cardiomyocyte phenotypic change by incubation of cells with hydroxyurea for several days ex vivo. Hydroxyurea incubation has been demonstrated to phenocopy age- and senescence-induced changes in neurons, but its utility for ageing studies with cardiac cells has not been examined. Incubation of neonatal rat ventricular myocytes with hydroxyurea for up to 7 days replicated specific aspects of cardiac ageing including reduced systolic calcium responses, increased alternans and a lesser ability of the cells to follow electrical pacing. Additional functional and structural changes were observed within the myocytes that pointed to ageing-like remodelling, including lipofuscin granule accumulation, reduced mitochondrial membrane potential, increased production of reactive oxygen species, and altered ultrastructure, such as mitochondria with disrupted cristae and disorganised myofibres. These data highlight the utility of alternative approaches for exploring cellular ageing whilst avoiding the costs and co-morbid factors that can affect longitudinal studies.

The mesially impacted mandibular third molar: The incidence and consequences of distal cervical caries in the mandibular second molar.

AIMS: Distal Cervical Caries (DCC) of the mandibular second molar (Md2M) is primarily related to retained mesially impacted third molars (Md3M). Treatment of this condition indicates the removal of the Md3M and the restoration of the Md2M and, on occasions, the loss of the Md2M. The aim of this study was to determine the incidence, treatment outcomes for patients, and calculate costs related to Md2M DCC. METHODS: A review of 121 patients who had Md3M removed due to Md2M DCC was undertaken to determine the treatment outcomes for patients. The number of patients affected by DCC of Md2M was calculated from the incidence of DCC (15%) in a cohort of patients requiring Md3M removal (1100) and the annual number of patients undergoing third molar surgery in England. Direct costs were calculated using NHS and independent treatment tariffs and indirect costs from Office of National Statistics (ONS). RESULTS: It is estimated that 152,000 patients in England undergo third molar removal on an annual basis. Approximately 27,000 Md3M are removed annually due to DCC of the Md2M; costing £27 m to treat with additional costs of £28 m if dental implant replacement of the Md2M is included. Total cost for treating Md2M DCC: £55 m/annum. CONCLUSIONS: Treating Md2M DCC and its consequences is expensive for healthcare funders such as the NHS and for patients. Md2M DCC is avoidable if patients who are at risk have prophylactic Md3M removal. This would offer potential and substantial savings in the financial cost of treating an otherwise avoidable disease.

Efficiency and effectiveness of orthodontic treatment within United Kingdom secondary care: a service evaluation.

OBJECTIVES: To evaluate the efficiency and effectiveness of Orthodontic treatment in the National Health Service (NHS) hospitals in England and to identify factors that may be predictive of the duration of Orthodontic treatment and number of patients' visits. DESIGN: Retrospective service evaluation. SETTING: The orthodontic departments of two NHS hospitals. METHODS: The data were collected from the clinical notes, the hospital data base and the pre- and post-treatment study models of 70 patients who were treated with fixed appliances. The pre- and post-treatment models were assessed using the Index of Orthodontic Treatment Need (IOTN) and the Peer Assessment Rating (PAR) index. RESULTS: (1) 98.5% of the patients treated with fixed appliances in both hospitals were in definite need for treatment, (2) The mean percentage PAR score reduction was 81.5%, (3) The mean treatment duration was 27 months with an average of 21 appointments, (4) Factors increasing treatment duration included being a female patient, class I malocclusion, IOTN 5, extractions, prescribing headgear wear, using functional appliances or quadhelixes and increased number of missed appointments, (5) Factors reducing the treatment time were male patients, class II or class III malocclusions and an increased number of emergency appointments. CONCLUSIONS: The hospitals demonstrated a high standard of orthodontic treatment.

Dental age estimation: periodontal ligament visibility (PLV)-pattern recognition of a conclusive mandibular maturity marker related to the lower left third molar at the 18-year threshold.

The purpose of this study was to explore the applicability of periodontal ligament visibility (PLV) at the 18-year threshold. This mandibular maturity marker is graded into four separate age related stages, PLV-A, PLV-B, PLV-C, and PLV-D. These are discernible on a dental panoramic tomograph (DPT). The sample comprised a total of 2000 DPTs evenly divided into half yearly age bands from 16.00 to 25.99 years with 50 females and 50 males in each age band. It was found that PLV-A and PLV-B had minimum values below the 18-year threshold. PLV-C and PLV-D in females had minimum values of 18.08 and 18.58 years, respectively. In males, the minimum values for PLV-C was 18.10 years and PLV-D was 18.67 years. It was concluded that the presence of PLV-C or PLV-D indicates that a subject is over 18 years with a very high level of probability.

Endothelin-1-stimulated InsP3-induced Ca2+ release is a nexus for hypertrophic signaling in cardiac myocytes.

Ca(2+) elevations are fundamental to cardiac physiology-stimulating contraction and regulating the gene transcription that underlies hypertrophy. How Ca(2+) specifically controls gene transcription on the background of the rhythmic Ca(2+) increases required for contraction is not fully understood. Here we identify a hypertrophy-signaling module in cardiac myocytes that explains how Ca(2+) discretely regulates myocyte hypertrophy and contraction. We show that endothelin-1 (ET-1) stimulates InsP(3)-induced Ca(2+) release (IICR) from perinuclear InsP(3)Rs, causing an elevation in nuclear Ca(2+). Significantly, we show that IICR, but not global Ca(2+) elevations associated with myocyte contraction, couple to the calcineurin (CnA)/NFAT pathway to induce hypertrophy. Moreover, we found that activation of the CnA/NFAT pathway and hypertrophy by isoproterenol and BayK8644, which enhance global Ca(2+) fluxes, was also dependent on IICR and nuclear Ca(2+) elevations. The activation of IICR by these activity-enhancing mediators was explained by their ability to stimulate secretion of autocrine/paracrine ET-1.

Nasofrontal Angle and Nasal Dorsal Aesthetics: A Quantitative Investigation of Idealized and Normative Values.

This study is a quantitative evaluation of the influence of the lower component of the nasofrontal angle on perceived attractiveness and threshold values of desire for rhinoplasty. The nasofrontal angle of an idealized silhouette male Caucasian profile image was altered incrementally between 106 and 148 degrees. Images were rated on a Likert scale by pretreatment patients (n = 75), laypeople (n = 75), and clinicians (n = 35). The results demonstrated that a nasofrontal angle of approximately 130 degrees is ideal, corresponding to a lower component of 60 degrees, with a range of 127 to 142 degrees deemed acceptable. Angles above or below this range are perceived as unattractive, and anything outside the range of 118 to 145 degrees is deemed very unattractive. Reduced nasofrontal angles, simulating a nasal hump deformity, of less than 115 degrees were deemed the least attractive. In terms of threshold values of desire for surgery, for all groups a threshold value of 148 degrees indicated a preference for surgery: for patients, the threshold value was 121 degrees or less; for lay people, the threshold value was 124 degrees or less; and similarly for clinicians, the threshold value was 118 degrees or less. Clinicians were the least critical, and patients appeared to be less critical than lay people. This stresses the importance of using patients as observers, as well as laypeople and clinicians, in facial attractiveness research. From the results of this study, it is recommended that in rhinoplasty planning, the range of normal variability of the nasofrontal angle, in terms of observer acceptance, is taken into account as well as the threshold values of desire for surgery.

Relationship between maxillary central incisor proportions and facial proportions.

STATEMENT OF PROBLEM: No universally accepted parameter exists for selecting maxillary central incisors (MCIs) relative to facial proportions. PURPOSE: The purpose of this prospective clinical study was to determine the relationship between MCIs and facial height and width in adults, intersex differences, and measurement differences between right and left MCI. MATERIAL AND METHODS: A prospective study was undertaken of 149 dental students (F:76; M:73) aged between 18 and 30 years. Anthropometric MCI and horizontal and vertical facial measurements were recorded with digital calipers by 1 operator. Correlation was investigated with Pearson correlation coefficients (α=.05). Two-sample t tests were used for intersex comparisons and paired t tests to compare right and left MCIs. Intraexaminer reliability was tested by remeasuring 25 participants and applying the Bland-Altman and Lin analyses. RESULTS: The mean MCI height was 10.28 mm (right and left) and the mean widths were 8.65 mm (right) and 8.66 mm (left). Intersex incisor differences existed for height measurements (M:F 0.54 mm [right], 0.46 mm [left]) and width measurements (M:F 0.26 mm) but not for width-to-height ratios (F=0.85; M=0.84). A mean ratio of 15.56 was found between bizygomatic width:tooth width (M=15.75, F=15.37) and of 17.93 between total face height:MCI height (M=17.97, F=17.89). Correlation coefficients were low for all tooth:face measurements. Intraexaminer reliability was clinically acceptable. CONCLUSIONS: Men had larger teeth and faces but similar width:height ratios. There was no significant size difference between right and left MCI, little individual relationship between tooth:face proportions, and insignificant sex influence. The "biometric ratio"' of 1:16 for MCI:bizygomatic width was not reconfirmed exactly. A ratio of 1:18 is proposed for MCI height to total face height (Tr-Me') and 1:12 for face height (N'-Me').

Comparison of the dental anomalies found in maxillary canine-first premolar transposition cases with those in palatally displaced canine cases.

AIM: To compare the developmental dental anomalies associated with maxillary canine-first premolar (MxCP1) transposition and those of palatally displaced canine (PDC) with each other and with the background prevalence in the Maltese population in order to elucidate whether the two conditions have similar or differing genetic backgrounds. MATERIALS AND METHODS: Dental records of 477 subjects with PDC, 57 subjects with MxCP1, and a control group of 500 subjects with no history of a PDC or tooth transposition were compared for canine eruption anomalies and hypodontia. RESULTS: A high frequency of bilateral occurrence was present for both canine malpositions and when unilateral, a trend to right-sided occurrence was evident. The occurrence of transpositions in the PDC group and of PDC in the MxCP1 group was higher than expected. The prevalence of incisor hypodontia was significantly higher in subjects with PDC and MxCP1, as compared to the control group. LIMITATIONS: The size of the MxCP1 group is relatively small. The study population is a small isolated Caucasian population and the results may not be applicable to other populations. CONCLUSIONS: There is no significant difference between the MxCP1 and PDC groups in the prevalence or distribution of hypodontia and each of these groups exhibits a higher prevalence of the other canine anomaly. These findings support the theory that PDC and MxCP1 form part of a group of interrelated dental anomalies that share a common genetic basis.

Pulmonary vein sleeve cell excitation-contraction-coupling becomes dysynchronized by spontaneous calcium transients.

Atrial fibrillation (AF) is the most common form of sustained cardiac arrhythmia. Substantial evidence indicates that cardiomyocytes located in the pulmonary veins [pulmonary vein sleeve cells (PVCs)] cause AF by generating ectopic electrical activity. Electrical ablation, isolating PVCs from their left atrial junctions, is a major treatment for AF. In small rodents, the sleeve of PVCs extends deep inside the lungs and is present in lung slices. Here we present data, using the lung slice preparation, characterizing how spontaneous Ca2+ transients in PVCs affect their capability to respond to electrical pacing. Immediately after a spontaneous Ca2+ transient the cell is in a refractory period and it cannot respond to electrical stimulation. Consequently, we observe that the higher the level of spontaneous activity in an individual PVC, the less likely it is that this PVC responds to electrical field stimulation. The spontaneous activity of neighbouring PVCs can be different from each other. Heterogeneity in the Ca2+ signalling of cells and in their responsiveness to electrical stimuli are known pro-arrhythmic events. The tendency of PVCs to show spontaneous Ca2+ transients and spontaneous action potentials (APs) underlies their potential to cause AF.

The aesthetic impact of upper lip inclination in orthodontics and orthognathic surgery.

BACKGROUND: The nasolabial angle, particularly its lower component, i.e. the upper lip inclination (ULI), is an important keystone in treatment planning. Normative data for this parameter are not available. OBJECTIVES: A quantitative evaluation of the aesthetic impact of ULI on perceived attractiveness and threshold values of desire for treatment was undertaken. METHODS: The ULI of an idealized silhouette profile image was altered incrementally between 61 and 100 degrees. Images were rated on a Likert scale by pre-treatment orthognathic patients (n = 75), laypeople (n = 75), and clinicians (n = 35). RESULTS: An ULI between 79 and 85 degrees is viewed as ideal, with a range of 73-88 degrees deemed acceptable. Angles above or below this range, down to 67 degrees and up to 94 degrees are perceived as slightly unattractive, and anything outside the range of 67-94 degrees is deemed very unattractive. For patients the threshold value of desire for treatment was 91 degrees and above and 64 degrees and below, and for both clinicians and lay people the threshold value was 94 degrees and above and 64 degrees and below. Patients appear to be more critical than lay and clinician groups. This stresses the importance of using patients as observers, as well as laypeople and clinicians, in facial attractiveness research. LIMITATIONS: The results are based on an idealized male Caucasian profile. CONCLUSIONS: It is recommended that in treatment planning, the range of normal variability of the ULI, in terms of observer acceptance, is taken into account as well as the threshold values of the desire for treatment.

Location and severity of root resorption related to impacted maxillary canines: a cone beam computed tomography (CBCT) evaluation.

BACKGROUND: The present investigation was designed to determine the location and severity of root resorption associated with impacted maxillary canine teeth using cone beam computed tomography (CBCT). A secondary aim was to identify possible influencing factors. METHODS: The radiological reports of 183 patients, radiographed with a small-volume CBCT focussed on the impacted maxillary canine teeth, were assessed. Eighty-five patients had resorption associated with the impaction. The CBCT image datasets were viewed to determine the location and severity of the lesions. RESULTS: A total of 110 impacted maxillary canine teeth resorbed 120 adjacent teeth, including 14 premolars and one permanen molar. The apical third and palatal surface were commonly involved. Fifty per cent of the resorptive lesions were mild, 20% moderate and 30% severe. There was no significant relation between age or gender on the number, location or severity of resorption. There was a statistically significant correlation between the number of impacted canine teeth an'd the number of teeth resorbed, as well as the tooth type and the surface involved in the resorption. CONCLUSIONS: All root levels and surfaces of teeth associated with impacted maxillary canine teeth can be resorbed to different levels of severity. Neither age nor gender influences the number, location or severity of the resorption.

Lip asymmetry and smile aesthetics.

Objective : To determine if lip asymmetry can affect lip aesthetics. Setting and Participants : A group of dentists (n = 40) and cleft patients (n = 40) were recruited from the dental hospital and cleft service. Interventions : Still photographic digital images of lips and teeth were manipulated to produce a computerized gradient of smile appearance with different degrees of upper-lip vertical asymmetry. These five photographs (with 0 mm representing "symmetry," and 1, 2, 2.5, and 3 mm, asymmetries) were assessed by participants using a 5-point Likert scale. Statistics : Descriptive statistics in addition to chi-square test were used to analyze the data. In order to satisfy the requirement of the chi-square test, the five smile ratings were reduced to three. Results : Lip asymmetry did affect relative smile aesthetics, as determined by dentists and cleft patients. Both the dentists and cleft patients rated the 0-mm photograph more attractive than the 2.5-mm and 3-mm smiles (P < .05). The 0-, 1-, and 2-mm smiles were indistinguishable for both dentists and cleft patients. Conclusion : Lip asymmetry affects smile aesthetics. However, cleft patients and dentists were tolerant of minor asymmetries. This suggests that small degrees of lip asymmetry do not affect relative smile aesthetics as much as large degrees of lip asymmetry (2.5 mm or more).

The influence of combined orthodontic-orthognathic surgical treatment on perceptions of attractiveness: a longitudinal study.

The purpose of this investigation was to quantitatively evaluate the influence of completing the orthognathic treatment process on patients' perceptions of attractiveness and their desire for surgical correction. The mandibular prominence of an idealized profile image was altered in 2 mm increments from -16 to 12 mm, in order to represent retrusion and protrusion of the mandible, respectively. These images were rated on a seven-point Likert scale by 50 patients at T1 (pre-treatment) and T2 (6 months following orthodontic appliance removal). At T1, mandibular retrusion became noticeable at -4 mm and protrusion at 2 mm. The results remained unchanged at T2. Surgery was desired from -9 mm at T1 and -10 mm at T2. For mandibular protrusion, surgery was desired from 3 mm at T1 and 4 mm at T2. The odds of desire for surgery were reduced by 85 per cent for those patients who had undergone bimaxillary surgery in relation to those with single jaw surgery. The lowest rated images demonstrated severe degrees of mandibular protrusion and retrusion. The highest rated images represented the idealized facial profile and minor variations thereof; there was little change in perception between T1 and T2. Going through the process of orthognathic treatment does not appear to have any significant effect on patients' perceptions of facial profile attractiveness or the limits of mandibular sagittal deviation at which they would desire surgery. The clinician's information provision during treatment does not seem to unduly influence orthognathic patients and does not make them more critical of jaw deformities.

How does variation in lower anterior face height influence perceived attractiveness? A quantitative investigation.

OBJECTIVE: The purpose of this investigation was to undertake an objective and quantitative evaluation of how severity of lower anterior face height (LAFH) variations influences perceived attractiveness. DESIGN: Cross-sectional study SETTING: St George's Hospital, London, UK PARTICIPANTS AND METHODS: The LAFH of an idealized male and female frontal facial image were altered in 2·5 mm increments from -20 to 20 mm (male images) and from -10 to 20 mm (female images), in order to represent reduction and increase in height of this region. These images were rated by a pre-selected group of pre-treatment orthognathic patients (n = 75), clinicians (n = 35) and laypersons (n = 75). OUTCOME MEASURES: Ratings on a seven-point Likert scale. RESULTS: With an increase in LAFH, desire for surgery became significant at 15-16 mm for male faces and 13-14 mm for female faces. With a reduction in LAFH, desire for surgery became significant at -14 to -17 mm for male faces; a smaller reduction of -6 to -8 mm led to a significant desire for surgery for female faces. CONCLUSIONS: The classical vertical facial trisection canon of upper face height as one-third (33·3%), midface height as one-third (33·3%) and LAFH as one-third (33·3%) of total anterior face height may be used as an 'ideal' proportional ratio. Mild LAFH variations were largely acceptable. In terms of the percentage LAFH to total anterior face height (TAFH) and anterior face height (AFH), observers did not desire surgery for LAFH variations of 25-42% of TAFH (40-66% of AFH) for male faces, and 28-42% of TAFH (45-66% of AFH) for female faces.

In vitro comparison of contemporary radiographic imaging techniques for measurement of tooth length: reliability and radiation dose.

OBJECTIVES: To measure the reliability of tooth length measurements taken using dental pantomograms (DPT), long cone periapical radiographs (PR), and cone beam computed tomography (CBCT) and to compare their effective radiation dose. SUBJECTS AND METHODS: A model containing sixteen anterior teeth was used to simulate a patient undergoing fixed appliance treatment. PRs were taken at standardized vertical angulations to the occlusal plane (0, 5, 10, 15, and 20°) using conventional and digital techniques. DPT and CBCT images were also taken. Measurements of radiation dosages were used to estimate a risk benefit analysis for each of the techniques. RESULTS: DPT consistently overestimated tooth lengths by 2 mm or more [mean: 2·34 mm; 95% confidence interval (CI): 1·4-3·3 mm]. CBCT consistently underestimated tooth length (mean: -0·89 mm; 95% CI: -0·44 to -1·33 mm). PRs taken at 90° angulation closely resembled the actual tooth length (mean: -0·14 mm; 95% CI: -0·64 to 0·37 mm), but overestimation occurred with increasing PR film angulation. The radiation dosages ranged widely: DPT plus eight PRs that would be necessary to assess all teeth and root length of the upper and lower labial segments amounted to 23 µSv. Radiation dose from CBCT ranged from 17·8 to 60 µSv, depending on equipment and settings.

Assessing the influence of asymmeftry affecting the mandible and chin point on perceived attractiveness in the orthognathic patient, clinician, and layperson.

PURPOSE: The purpose of this investigation was to undertake an objective and quantitative evaluation of how severity of asymmetries affecting the mandible and chin point influence perceived attractiveness. MATERIALS AND METHODS: The mandible and chin point of idealized male and female frontal facial images were altered in 5-mm increments from 0 to 25 mm and to the left and right, to represent horizontal, vertical, and combined asymmetry affecting these regions. These images were rated on a 7-point Likert scale by a preselected group of orthognathic patients before treatment, clinicians, and laypeople. RESULTS: In relation to a 5-mm asymmetry, observers progressively decreased attractiveness ratings and increased the desire for surgery for greater asymmetries. Clinicians and patients were found to be more critical than laypeople. The desire for surgery decreased by 3% for each year increase in age, was 53% less for men, and 45% greater for white observers. CONCLUSIONS: Asymmetry of 10 mm is perceived as being significant; at 5 mm and below, it is largely unnoticed. The greater the degree of asymmetry greater than 10 mm, the more noticeable and the greater the desire was for correction. Clinician and patient ratings were similar and more critical than ratings of laypeople. A desire for surgery was negligible for 5 mm of asymmetry but increased considerably at 10 mm and continued to increase with greater degrees of asymmetry. The highest-rated images showed perfect bilateral symmetry, whereas the lowest-rated images showed significant degrees of mandibular and chin asymmetry.