Soft-tissue chin profiles in aesthetically normative facial features: comparison of three-dimensional camera with...

Preoperative chin profile assessment in orthognathic surgery remains limited by reliance on two-dimensional (2D) cephalometric standards. Advances in three-dimensional (3D) facial scanning allow comprehensive, multi-dimensional evaluation of soft-tissue facial morphology; however, evidence-based aesthetic assessment of normative chin profiles using three-dimensional facial imaging remains limited. Hence, this study aimed to investigate soft-tissue chin profiles in clinically aesthetically normative participants using a 3D camera system, comparing with traditional 2D cephalometric values. A total of 100 aesthetically normative participants were enrolled based on expert assessment of silhouette images derived from 3D scans. Chin profile data including chin prominence (pogonion to subnasale vertical: Pg' to SnV), upper and lower lip position, chin-throat length, and lip-chin-throat angle (LCTA) were analysed. 3D facial scanning in male participants demonstrated significantly greater chin retrusion (P < 0.001), increased upper lip prominence (P = 0.028) and reduced LCTA (P < 0.001) compared with 2D cephalometric norms. Similarly, female participants showed significantly greater chin retrusion (P < 0.001), increased lower lip prominence (P = 0.018), decreased chin-throat length and LCTA (P < 0.001). In conclusion, based on the validated accuracy and precision of the 3D camera facial scan system which refer to clinical appraisal in our population, particularly Pg' to SnV and LCTA in both male and female participants, 3D camera facial scan revealed more chin retrusion and smaller LCTA angle with aesthetically normative profiles compared to traditional and individual 2D cephalometric norms.