Optimal anteroposterior position of the maxillary central incisors and its relationship to the forehead in adult Asian males.

Abstract

Introduction: The objective of this study was to determine the optimal anteroposterior (AP) position of the maxillary central incisors (CIs) and its relationship with the forehead in adult Asian males.

Methods: Smiling profile photographs of 60 Asian males were obtained and divided into 3 groups based on the judged AP position of CI (just about right, too far forward, and too far back), as evaluated by orthodontists and laypersons. The CI position and forehead inclination (FI) were measured relative to the glabella vertical (GV). Statistical analysis was used to test for differences among groups, differences between orthodontists and laypersons, and the relationship between CI position and FI.

Results: The optimal CI position was 0.86 mm anterior to GV. There were statistical differences between orthodontists and laypersons in the too-far-forward (P = 0.0001) and too-far-back (P = 0.0001) groups. One-way analysis of variance revealed significant differences among the 3 groups (P <0.001) for both orthodontists and laypersons, with post hoc analysis confirming that all groups differed significantly from one another (P <0.05). CI position and FI showed a moderate positive correlation (r = 0.42; P <0.001).

Conclusions: In Asian males, the AP position of the CI can be evaluated relative to the forehead to optimize the CI position and maximize facial harmony.