OBJECTIVE: Comparison of global versus landmark analyses of facial asymmetry using three-dimensional photogrammetry to establish a precise method for evaluating facial asymmetry. DESIGN: The landmark-based approach utilized anthropometric data points. Our global approach involved registration of mirror images, independent of a midplane, to calculate a root mean square (RMS) value. We analyzed precision and technical and operator error of both methods. PARTICIPANTS: Three hundred fifty adults participated in this study. RESULTS: We found that the global method has better precision and repeatability with a significantly lower error rate than the landmark-based method. In adults, the average RMS was 0.6253 mm with a standard deviation of 0.16. CONCLUSIONS: Our facial asymmetry measurement is more accurate than landmark-based measurements. This method is quick, reliable, and results in generation of a RMS score and a corresponding color-coded facial map that highlights regions of higher and lower asymmetry. This method may be used as a screening tool for asymmetry in both the clinical and research settings.
OBJECTIVE: Comparison of global versus landmark analyses of facial asymmetry using three-dimensional photogrammetry to establish a precise method for evaluating facial asymmetry. DESIGN: The landmark-based approach utilized anthropometric data points. Our global approach involved registration of mirror images, independent of a midplane, to calculate a root mean square (RMS) value. We analyzed precision and technical and operator error of both methods. PARTICIPANTS: Three hundred fifty adults participated in this study. RESULTS: We found that the global method has better precision and repeatability with a significantly lower error rate than the landmark-based method. In adults, the average RMS was 0.6253 mm with a standard deviation of 0.16. CONCLUSIONS: Our facial asymmetry measurement is more accurate than landmark-based measurements. This method is quick, reliable, and results in generation of a RMS score and a corresponding color-coded facial map that highlights regions of higher and lower asymmetry. This method may be used as a screening tool for asymmetry in both the clinical and research settings.
Authors: Motoki Katsube; Sara M Rolfe; Stephanie R Bortolussi; Yutaka Yamaguchi; Joy M Richman; Shigehito Yamada; Siddharth R Vora Journal: Orthod Craniofac Res Date: 2019-05 Impact factor: 1.826
Authors: Zhenqi Zhao; Lizhe Xie; Dan Cao; Iman Izadikhah; Pengcheng Gao; Yang Zhao; Bin Yan Journal: Dentomaxillofac Radiol Date: 2020-08-13 Impact factor: 2.419