Effect of Observer's Sex and Chin Prominences on the Perception of the Lower Lip-Chin Prominence Angle.

This study aimed to identify the preferred range of lower lip-chin prominence angles in the Korean population and evaluate the effect of the individual lower lip-chin prominence angle on perceptions of esthetic chin profile.Chin prominence silhouettes were used to assess the lower lip-chin prominence preference. The observers randomly categorized each image as (1) normal, (2) slightly abnormal but not requiring surgical correction, and (3) abnormal and requiring surgery. Individual lower-chin prominence angles of all observers were analyzed using standardized clinical photographs.The normal range of lower lip-chin prominence angle is 0° to 25°; socially acceptable range is 0° to -10°, 25° to 40°; range needing surgery is -10° to -30° and 40° to 45°. Women are more tolerant to chin protrusion. A protrusive chin is more acceptable in observers with retrusive chin profile.Skeletal Class II profile is more acceptable than skeletal Class III in the Korean population. The individual lower-chin prominence angle could affect perception of desired surgery. These findings indicate that patient-specific treatment planning is important in achieving satisfaction in chin surgery.