Aesthetic evaluation of the sagittal distance between the upper incisor and the anterior nasal spine on profile

Abstract:

Objective：To evaluate the relationship between the esthetic profile and the sagittal distance between the upper incisor（UI） and the anterior nasal spine（ANS） to provide the basis for repositioning UI. Methods：The position of the ANS in 53 patients，besides the distance from the ANS to the pterygomaxillary fissure（Ptm） and the angle of the ANS-Ptm line between the true horizontal （HOR） were evaluated before and after orthodontic treatment. Experienced orthodontists evaluated photographs of males and females who had completed orthodontic treatment，and selected the most attractive photographs. With the help of visual treatment objective（VTO） in Dolphin，move UI on the HOR and these photographs were edited to simulate the profiles at different sagittal UI-ANS distances on the HOR，as perceived by orthodontists and laypersons. Results：The distance of ANS-Ptm in pretreatment was （50.67±0.96） mm，and in posttreatment was （50.61±0.45） mm. The angle of the ANS-Ptm line between HOR in pretreatment was 4.37°±0.53°，and in postpretreatment was 4.75°±0.53°. No significant differences were found for the ANS-Ptm distances and the angle between the ANS-Ptm and HOR during orthodontic treatment（P>0.05）. For male profile，orthodontists gave the highest evaluation to the change of sagit－tal UI-ANS distance at （0 mm），and laypersons gave the highest evaluation to （-1 mm）（P<0.05）. For female profile，orthodontists and laypersons gave the highest evaluation to the change of sagittal UI-ANS distance at （0 mm）（P<0.05）. Conclusion：No change in the position of ANS occurs during the orthodontic treatment. The attractiveness of profiles is closely related to the sagittal UI-ANS distance for males and females.