title: Characteristics of Posed Smiles for Class III Female Patients Before and After Osteotomy Using Principal Component Analysis.
abstract: The purpose of this study was to clarify characteristics of posed smiles for Class III female patients before and after orthognathic surgery. Just before retrusion surgery and the removal of fixation plates, 2 sets of posed smiles were recorded for 7 Class III female patients. As normal controls, 7 healthy female volunteers were also recorded. Using our video-based motion analyzing system, range images and 5 × 5 virtual grids projected onto the lips were recorded for all patients while making a posed smile. The gravity for each area in the lips was calculated from the intersections of the virtual grids. Principal component analysis was applied to the normalized virtual grids, that is, a homologous model of lip shape, for all frames of the posed smiles. While the sample size was too small to generalize from these results, we found that the upper vermilion shifted posteriorly and laterally in posed smiles for Class III female patients after retrusion surgery as compared with the preoperative posed smiles. In addition, the characteristic lip movements during postoperative posed smiles for Class III female patients did not resemble those of the normal controls.
authors.affiliation: *Department of Oral and Maxillofacial Surgery, Graduate School of Medicine, Yamaguchi University, Yamaguchi †Department of Oral and Maxillofacial Surgery II, Graduate School of Dentistry, Kyushu University, Kyushu, Japan.
authors.forename: Katsuaki
authors.initials: K
authors.lastname: Mishima
authors.forename: Mami
authors.initials: M
authors.lastname: Shiraishi
authors.forename: Yui
authors.initials: Y
authors.lastname: Kawai
authors.forename: Hirotsugu
authors.initials: H
authors.lastname: Umeda
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nakano
authors.forename: Yoshiya
authors.initials: Y
authors.lastname: Ueyama
mesh_terms: D000293:Adolescent; D000328:Adult; D005149:Facial Expression; D005260:Female; D006801:Humans; D008046:Lip / Q000502:physiology; D010027:Osteotomy / Q000379:methods*; D025341:Principal Component Analysis / Q000379:methods*; D012904:Smiling / Q000502:physiology*; D055815:Young Adult