Chulalongkorn University Dental Journal

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Background/objectives To evaluate the attractiveness of smile arcs obtained by different vertical bracket positions and occlusal plane angles (OPAs). Materials and methods Three dental models represented tooth position after leveling with three bracket positions: a conventional bracket position (Con) according to a guideline based on tooth measurement, and bracket positions resulted in extruding (Ext) or intruding (Int) the maxillary incisors. Photographs of the three models were taken at OPAs of 5, 10, and 15° to the true horizontal. The photographs were digitally morphed onto a posed female smile. Nine smile arc photographs were obtained and assessed by a group of orthodontists, dentists, and laypeople. Results At an average OPA (10°), the Con10 image received a significantly higher esthetic score compared with the Ext10 and Int10 images. The Ext group smile attractiveness significantly decreased from an OPA of 5° (Ext5 image) to 10° (Ext10 image), while the attractiveness of the Int group significantly increased with increasing OPAs. Conclusions Vertical bracket position and OPA affected smile arc esthetic perception. At an average OPA, the smile arc obtained by bracket position based on tooth measurement resulted in the most attractive smile arc compared with that obtained by bracket positions resulted in extruding or intruding the maxillary incisors. Extruding the maxillary incisors may be beneficial to those with a low OPA, while intruding the maxillary incisors may be done in patients with a high OPA without showing a flat or reversed smile arc.



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