FitJaw Mobile, a virtual reality device applied to dentistry: An analysis based on two patient treatments.

STATEMENT OF PROBLEM: Virtual reality (VR) has improved significantly in the last decade and has been applied to different fields, including medicine, dentistry, and physiotherapy. VR has been used for the innovative treatment of painful conditions, especially when traditional exercise therapies were unsuccessful because of patient noncompliance. PURPOSE: The purpose of this study was to analyze the use of VR as an aid when using exercises to manage temporomandibular disorders (TMDs). MATERIAL AND METHODS: Two White women diagnosed with TMDs of muscular origin (one with muscular pain and the other with reduced mouth opening) were referred to the Department of Prosthodontics of the University of Seville, where they were enrolled in an exercise program using the VR software program FitJaw Mobile. Both had been treated the previous year with an occlusal device for TMD of muscular origin, but their symptoms had not improved. RESULTS: For both patients, the functional movement limitation and the chronic pain improved noticeably. CONCLUSIONS: The use of VR when doing jaw exercises can improve outcomes and compliance.

Comparative analysis of smile esthetics between top celebrity smile and a Southern European population.

STATEMENT OF PROBLEM: The analysis of different parameters involved in the esthetic perception of the smile is important for the correct planning of cosmetic dental treatments. PURPOSE: The purpose of this study was to analyze the differences in the main parameters of smile esthetics among celebrities identified as having the best esthetic smiles and a young Southern European population. MATERIAL AND METHODS: The study consisted of a control group of 144 dental students from the University of Seville (69.4% women; 30.6% men) with a mean ±standard deviation age of 23.19 ±0.5 years and photographs of 58 celebrities identified as having the best esthetic smiles (74.1% women; 25.9% men) with a mean ±standard deviation age of 42.09 ±2.25 years. Photographs of the celebrities were obtained from the Internet, and standardized photographs were made of the control group. The variables measured were smile line, smile arc, incisal edges and lower lip relationship, smile width, dental midline deviation and tilting, buccal corridor widths, and angulation discrepancy between interpupillary line and commissural line and between interpupillary line and occlusal plane. The data obtained were processed in a statistical software program for a descriptive statistical analysis and for inferential analysis parametric statistical tests by applying the Wilcoxon, chi-square, Student t, and kappa index tests (α=.05). RESULTS: Statistically significant differences (P<.01) were found between the groups in terms of smile width, smile arc, midline deviation and tilting, and angulation discrepancy between the interpupillary line and the commissural line. Smile arc was the only variable found to be different (P<.01) in relation to sex. CONCLUSIONS: Characteristics of the most esthetic smiles were no deviation or tilting of the maxillary midline, showing a greater number of teeth in the smile, displaying incisal edges parallel to the lower lip (particularly in women), and displaying occlusal and commissural planes parallel to the interpupillary line.

A comparison of the passive fit of a 3-unit implant-supported fixed partial denture fabricated by lost-wax casting, milling soft metal blocks, or direct metal laser sintering: An in vitro study.

STATEMENT OF PROBLEM: Stresses induced by implant-supported prostheses are related to mechanical complications. However, how the manufacturing method affects the generated stresses is unclear. PURPOSE: The purpose of this in vitro study was to compare the passive fit of 3-unit cobalt-chromium partial prostheses fabricated by using 3 different methods: conventional casting (milled resin with lost-wax method), machined (milling soft metal blocks), or sintered (direct metal laser sintering). MATERIAL AND METHODS: Thirty 3-unit implant-supported cobalt-chromium fixed prostheses were fabricated, 10 with each method. Four strain gauges were placed over an in vitro resin model with 2 implants in it; 2 gauges were placed above and 2 on the sides to measure the microdeformations caused by placing the structures above the implants in longitudinal flexion, vertical flexion, or torsion, before and after tightening the screws. An inferential analysis was carried out by using a statistical software program, and the Wilcoxon and Kruskal-Wallis tests were applied and then complemented with the Mann-Whitney test for multiple comparisons with the Bonferroni correction (α=.01). RESULTS: The mean longitudinal deformation, vertical flexion, and torsional deformation values increased after tightening the screws with each of the 3 fabrication methods. Significant differences (P<.01) were found for all 3 methods before and after screw tightening. After screw tightening, the machined structures, followed by sintered structures, and the cast structures (P<.05) had smaller deformations in the X, Y, and Z dimensions. The longitudinal deformation was less in machined structures, and vertical flexion deformation was less in machined and sintered structures than in cast structures (P<.05). CONCLUSIONS: The deformations registered in the in vitro model increase considerably after screw tightening, which indicates the lack of passive fit. Machined structures provide a better passive fit, followed by sintered structures, and the cast structures had the poorest fit.

Esthetic assessment of celebrity smiles.

STATEMENT OF PROBLEM: Guidelines for planning esthetic outcomes are sparse. The present study evaluated the most noticeable characteristics of the celebrities with the most esthetic smiles. PURPOSE: The purpose of this observational study was to assess the smiles of celebrities based on descriptive esthetic smile criteria and to compare male and female celebrity smiles based on dentally esthetic smiles. MATERIAL AND METHODS: An internet search for the "most beautiful celebrity smile ranking" was conducted in 2019, resulting in 50 celebrities that had been voted for having the most beautiful smiles. A second search was conducted to locate images of the identified individuals with the whole face and a broad smile. RESULTS: The most frequent characteristics of the studied variables were a normal smile line (70.7%), incisal edges parallel to the lower lip (56.1%), maxillary anterior incisal edges touching the lower lip (48.8%), a smile width of 10 teeth (53.7%), a facial midline coincident with the maxillary dental midline (51.2%), and average buccal corridors (78%). Statistically significant differences between men and women were only found in the smile arch (P<.01). CONCLUSIONS: Celebrities voted as having the most beautiful smiles comply with most of the characteristics described as esthetically pleasing, except for midline deviations. The general population is influenced by factors other than the individual's smile.

Width/Length Ratio in Maxillary Anterior Teeth. Comparative Study of Esthetic Preferences among Professionals and Laypersons.

PURPOSE: Many studies have examined the esthetic preferences of professionals in the maxillary anterior region; however, only a few have taken into account the ratios that are more frequent within the population or other ratios suggested in the literature as ideal. Previous studies also failed to compare them with the esthetic preferences of the lay population with regards to the smile. The purpose of this study is to highlight the differences when perceiving the esthetics of smiles between general dentists and laypersons, and linking them with the width/length of the maxillary anterior teeth. MATERIALS AND METHODS: Photographs of the full face of a female subject were modified with Photoshop CS regarding the length/width relationships of the 6 maxillary anterior teeth. The three modifications made were: (a) 80% length/width, (b) 85%, length/width, and (c) 85% length/width in central incisors, 80% length/width in lateral incisors and canines. Three sequences of photograph pairs were created with different ratios and presented in PowerPoint to a sample of 100 general dentists and 100 laypersons. RESULTS: The ratio considered as the most esthetic by the majority of the judges was 85% for central incisors and 80% for lateral incisors and canines, with a statistically significant difference (p < 0.01). There was no statistically significant difference in the esthetic preferences of the studied populations either due to gender or professional experience of the dentists (p > 0.01). CONCLUSIONS: According to the results obtained in this study, professionals and laypersons considered a width/length ratio of 85% for maxillary central incisors and 80% for lateral incisors and canines as the most esthetic for maxillary anterior teeth. These results do not support findings from other studies previously published with similar ratios in central incisors, lateral incisors, and canines. CLINICAL IMPLICATION: Today clinicians practice in a treatment environment where not only function and utility but also esthetics is demanded in almost every procedure. Restoring/maintaining function is considered essential in any restorative dentistry treatment, but the esthetic aspects of any treatment should never be forgotten. This study was motivated by the increasing importance of obtaining a better appreciation of the perception of smile beauty, and of the role of maxillary teeth width/length ratio on the perception of dental esthetics.

Prevalence of alterations in the characteristics of smile symmetry in an adult population from southern Europe.

STATEMENT OF PROBLEM: Deviation from the facial midline and inclination of the dental midline or occlusal plane has been described as extremely influential in the layperson's perceptions of the overall esthetics of the smile. PURPOSE: The purpose of this study was to determine the prevalence of deviation from the facial midline and inclination of the dental midline or occlusal plane in a selected sample. MATERIAL AND METHODS: White participants from a European population (N=158; 93 women, 65 men) who met specific inclusion criteria were selected for the present study. Standardized 1:1 scale frontal photographs were made, and 3 variables of all participants were measured: midline deviation, midline inclination, and inclination of the occlusal plane. Software was used to measure midline deviation and inclination, taking the bipupillary line and the facial midline as references. Tests for normality of the sample were explored and descriptive statistics (means ±SD) were calculated. The chi-square test was used to evaluate differences in midline deviation, midline inclination, and occlusion plane (α=.05) RESULTS: Frequencies of midline deviation (>2 mm), midline inclination (>3.5 degrees), and occlusal plane inclination (>2 degrees) were 31.64% (mean 2.7±1.23 mm), 10.75% (mean 7.9 degrees ±3.57), and 25.9% (mean 9.07 degrees ±3.16), respectively. No statistically significant differences (P>.05) were found between sex and any of the esthetic smile values. CONCLUSIONS: The incidence of alterations with at least 1 altered parameter that affected smile esthetics was 51.9% in a population from southern Europe.

Biometric analysis of the clinical crown and the width/length ratio in the maxillary anterior region.

STATEMENT OF PROBLEM: Restorative dentistry often involves correcting tooth size discrepancies. Therefore, dental biometrics should play an important role in the planning of an esthetic restoration. PURPOSE: The purpose of this study was to analyze the clinical crown width, length, and width/length ratio of maxillary central incisors, lateral incisors, and canines in an adult population. The study also aimed to determine whether a correlation exists between natural tooth dimensions and the optimal tooth dimension guidelines suggested for planning esthetic restorations. MATERIAL AND METHODS: Stone casts were poured from irreversible hydrocolloid impressions of 412 healthy adult participants. These casts were used to measure the maximum mesiodistal width and maximum crown-root length of the maxillary central incisors, lateral incisors, and canines with a digital precision caliper (0.01 mm). The width/length ratio was calculated for each tooth, and 40 casts were selected to test the reliability of the measuring method. RESULTS: The mean age of the participants in the sample was 33.94 years; 60.7% were women and 39.3% were men. The mean width value was 8.71 mm for central incisors, 6.75 mm for lateral incisors, and 7.81 mm for canines. The mean length was 10.23 mm for central incisors, 8.59 mm for lateral incisors, and 9.93 mm for canines. The average width/length ratio was 85% for central incisors and 79% for lateral incisors and canines. CONCLUSION: The data obtained from the population studied are similar to those from previous research studies with similar methodology. However, great discrepancies in the absolute values were found when compared with other studies of ideal tooth dimension guidelines on the personal preferences and the esthetic perception of dentists. The perception of what is considered natural seems to differ from what is considered esthetically perfect.