Smile prevails over other facial components of male facial esthetics.

BACKGROUND: The aim of this study was to assess whether scores assigned to the eyes, nose, mouth, and chin regions work as predictors of full smiling face scores. METHODS: In this cross-sectional study, the authors used the facial photographs of 86 smiling men. Photographs yielded 5 components: 1 of the face itself and 4 subcomponents (eyes, nose, mouth, and chin region). Raters assigned the photographs beauty scores that the authors measured morphometrically. The authors analyzed the predictive ability of the subcomponents against that of the full face. RESULTS: The subcomponents were statistically significant predictors of facial beauty (mouth: r2 = 0.38, P < .0001; eyes: r2 = 0.14, P < .0001; chin region: r2 = 0.09, P < .0001; nose: r2 = 0.02, P = .05). The more beautiful people had several statistically significant characteristics, such as narrower faces. CONCLUSIONS: Facial subcomponents are predictive factors of the male smiling face and contribute in the following descending order of importance: mouth, eyes, chin region, and nose. PRACTICAL IMPLICATIONS: The results suggest that for many people improvement in smile esthetics also likely will exert a more positive effect on facial beauty than will other procedures (for example, rhinoplasty).

Bond strength of metallic brackets after dental bleaching.

OBJECTIVE: To test the hypothesis that there is no difference between the action of at-home and in-office vital bleaching on the shear bond strength of metallic brackets bonded with composite resin 24 hours after bleaching. MATERIALS AND METHODS: Forty-five human upper premolars were randomly divided into three groups: (1) control, (2) 10% carbamide peroxide at-home bleached, and (3) 35% hydrogen peroxide in-office bleached. Twenty-four hours after bleaching the teeth were pumiced, bonded with metallic brackets, and stored in distilled water. One day after bonding the shear bond strength of the brackets was determined. RESULTS: The mean shear bond strength of Group 1 (control) and Group 2 (carbamide peroxide bleached) were not statistically different. Group 3 (hydrogen peroxide bleached) had a significantly lower mean shear bond strength than Group 1 and Group 2. CONCLUSIONS: The hypothesis is rejected. Use of 10% carbamide peroxide bleaching does not significantly alter shear bond strength values. On the other hand, use of 35% hydrogen peroxide bleaching significantly reduces these values and diminishes the amount of resin remnant on the tooth surface after bracket debonding.