Does the vertical position of maxillary central incisors in men influence smile esthetics perception?

INTRODUCTION: The aim of this study was to investigate whether there is any influence on the perception of smile esthetics among orthodontists and laypersons, with regard to different vertical positions of the maxillary central incisors. METHODS: Frontal smile photographs digitally altered at full-face view and close-up view of 2 adult men aged between 20 and 30 years were used. Six vertical positions of the central incisors were created, with changes of 0.5 mm. The images were randomly assembled in an album that was presented to 53 orthodontists and 53 laypersons, who evaluated the attractiveness of the images by using visual analog scales. Comparison among the images was performed using 1-way analysis of variance, with Tukey post-hoc test. To compare the distribution of the mean scores between the full-face and close-up smile views, and between orthodontists and laypersons, the Student t test was used. The level of significance was established at 5%. RESULTS: The best evaluations presented the following: (a) the gingival margins of the central incisors corresponded to, or were up to, 1 mm below the line of the canine gingival margins, and (b) the incisal step between the central and lateral incisors was from 1.0 to 2.0 mm. The smiles considered least attractive showed (a) the central incisor gingival margins were 1.0 mm above or 1.5 mm below the canine gingival margins, and (b) no step, or a step of 2.5 mm, between the central and lateral incisors. CONCLUSIONS: The results of this study suggested that, in men, slightly extruded central incisors were esthetically more attractive than intruded incisors.

Is the growth pattern in mouth breathers comparable with the counterclockwise mandibular rotation of nasal breathers?

INTRODUCTION: The aim of this longitudinal study was to investigate mandibular rotation and angular remodeling in mouth-breathing children compared with nasal-breathing children. METHODS: The sample included 55 severely obstructed mouth-breathing children (mean age, 6.1 years) and 55 nasal-breathing children (mean age, 7.3 years). The cephalograms at baseline and after 1 year were traced and measured, and superimpositions were made to determine true mandibular rotation, apparent rotation, and angular remodeling. The significance level was set at 5%. RESULTS: The mouth-breathing children had a longer face cephalometric pattern compared with nasal-breathing children. No cranial deflection differences were observed. No changes in the vertical growth pattern were observed during the 1-year period in either group. There were no statistically significant differences between the groups regarding apparent rotation (mouth breathing, -0.54°, vs nasal breathing, -0.41°). In comparison with the nasal breathers, the mouth breathers showed statistically significant lower yearly rates of counterclockwise true rotation (mouth breathing, -0.60°, vs nasal breathing, -1.31°) and angular remodeling (mouth breathing, 0.06°, vs nasal breathing, 0.87°). CONCLUSIONS: Mouth-breathing children had a hyperdivergent cephalometric pattern, but against all expectations, counterclockwise true mandibular and apparent rotations were the average observations. Mouth-breathing children showed less true rotation and angular remodeling than did nasal breathers; however, apparent rotations were similar.