Effects of transverse relationships between maxillary arch, mouth, and face on smile esthetics

Abstract

Objective: To identify the ideal ratios between the widths of the maxillary arch, mouth, and face, respectively, and to determine the range of acceptable esthetic variations based on these ideal ratios. Materials and Methods: A photograph of a young female with a harmonious smile was selected and digitally altered to produce two sets of images. The first image showed an altered intercanine width, while the second one showed an altered oral fissure breadth. These alterations were independently rated by judges, including 23 orthodontists and 30 undergraduates. The MannWhitney U-test was used to compare the scores given by male and female judges and those given by professional and nonprofessional judges. Results: The following ideal transverse ratios were determined: intercanine width/oral fissure breadth, 0.638; oral fissure breadth/interparopia width: the distance between left and right paropia, 0.617; and intercanine width/face width at the level of the labial commissures, 0.300. A range of 210% to +10% was proposed as the thresholds of esthetic smile evaluations. It was shown that gender of the raters had no effect on the rating of photographs, nor were there any statistically significant differences between the professional and nonprofessional judges' ratings. Conclusions: Balanced transverse relationships in the facial region are important for smile esthetics, and there is a wide range of esthetically acceptable variations in the transverse relationships between the maxillary arch, mouth, and face. (Angle Orthod. 2016;86:135-141.)

Correlation Between Transverse Maxillary Discrepancy And The Inclination Of First Permanent Molars. A Pilot Study

“…20 Aunque no hay estudios que hayan correlacionado las variables aquí evaluadas, otros investigadores han 22 These data, together with the correlation reported in the present study between maxillary discrepancy and molar inclination, suggest that transversal lengths play an important role in craniofacial morphology, and that clinicians should analyze this role more carefully, not only for diagnosis and planning purposes, but also for follow ups.…”

“…Por su parte, Zhang et al, en 2016, reconocieron una relación importante entre las medidas transversales y el arco maxilar, la boca y la cara. 22 Estos datos, en conjunto con la correlación reportada en el presente estudio entre discrepancia maxilar e inclinación molar, llevan a proponer que las longitudes transversales juegan un rol importante en el establecimiento morfológico craneofacial, y que los clínicos deben darle mayor importancia a su análisis, no solo para el diagnóstico y la planeación, sino además para el seguimiento de los tratamientos.…”

Evaluation of the maxillary midline, curve of the upper lip, smile line and tooth shape: a prospective study of 140 Caucasian patients

“…This is an important factor when planning anterior restorations, since consideration is required of both smile width and the number of teeth exposed. Variations in smile width allow for a broad range of situations considered to be aesthetically agreeable [50].…”

Effect of Subject Rotation on Assessment of Esthetic Dental Ratios: A Simulation Study

“…Considering the acceptable deviation of the ratio from the ideal (without rotation) as −10% to + 10% [ 16 ], the ratio of lateral to central incisor deviates from the acceptable range when there was rotation of more than 7 degrees on either side (Tables 2 and 3 ). When the ratio of the canine to lateral incisor was evaluated, it was within the limits of ten percent till the model was rotated up to 10 degrees on either side.…”