Morphometric facial analysis: a methodology to create lateral facial images

Introduction: Currently, the majority of research in facial analysis using computational morphing methods focuses exclusively on analysis of frontal facial projections. Lateral facial morphing analysis has not been extensively investigated, and landmark features critical to specify registry points are unknown. This study aims to (1) determine the quantity of registry points (RP) required to create realistic lateral faces and (2) determine key facial registry point landmarks required to create synthetic lateral faces. Method: 36 synthetic lateral faces with a 50 to 250 RP were created to determine the ideal quantity of RP to create a realistic lateral image; ear, eyebrow, eye, nose, lips, hairline, facial outline, and overall outline were evaluated by an expert panel of seven evaluators using a 1 to 5 point Lickert scale rating system. Result: ANOVA single-variable analyses revealed significant differences when comparing templates of 200 and 250 RP with 50 and 100 RP templates (p < 0.05). Furthermore, analysis of all key landmark areas of the face indicated significant differences between different registry points except for 200 and 250 registry point markers. Kruskal-Wallis statistical analysis revealed the landmarks varied significantly from 50 to 200 RP,but had no significance with 200 and 250 RP. Conclusion: The most ideal quantity of RP used for the creation of realistic lateral faces was in the range of 200 RP. Defined lateral facial registry point landmarks generated successful realistic faces.