Three-Dimensional Analysis of the Correlation Between Soft Tissue and Bone of the Lower Face Using Three-Dimensional Facial Laser Scan

Background: The prime aims of this study were to establish cephalometric linear and angular normative values of the lower face using a three-dimensional (3D) analysis in Korean individuals, and validate whether the linear and angular measurements using 3D laser scanner are comparable with measurements using 3D computed tomography (CT). Methods: In this study, 40 Korean individuals aged between 18 and 60 years were enrolled. Using 3D CT scan and 3D laser scanner, linear and angular values of the lower face were measured and recorded. Statistical analysis was carried out to verify the concordance and correlation between two 3D imaging modalities. Results: The 40 samples consisted of 11 women with a mean age of 40.8 +/- 14.5 years and 29 men with a mean age of 29.7 +/- 15.0 years. The results demonstrated the difference between sex and the tendency of asymmetry on both sides. Among different methods of measuring angular values, the gonial angle (GA) between tragion' (Tr')-gonion' (Go')-menton' (Me') from 3D laser scanning and between articulate-gonion-menton from CT scan demonstrated a good concordance and a high correlation. Conclusions: The GA measured between Tr'-Go'-Me' using a 3D facial laser scan was comparable with values from 3D CT scan. The reference points and the GA, which we assessed here for 3D laser scanning, can be a reliable alternative method evaluating mandibular angles for assessing patients and surgical planning in plastic and orthognathic surgery.