title: A novel three-dimensional smile analysis based on dynamic evaluation of facial curve contour.
abstract: The influence of three-dimensional facial contour and dynamic evaluation decoding on factors of smile esthetics is essential for facial beauty improvement. However, the kinematic features of the facial smile contour and the contribution from the soft tissue and underlying skeleton are uncharted. Here, the cheekbone-maxilla contour and nasolabial fold were combined into a "smile contour" delineating the overall facial topography emerges prominently in smiling. We screened out the stable and unstable points on the smile contour using facial motion capture and curve fitting, before analyzing the correlation between soft tissue coordinates and hard tissue counterparts of the screened points. Our finding suggests that the mouth corner region was the most mobile area characterizing smile expression, while the other areas remained relatively stable. Therefore, the perioral area should be evaluated dynamically while the static assessment outcome of other parts of the smile contour contribute partially to their dynamic esthetics. Moreover, different from the end piece, morphologies of the zygomatic area and the superior part of the nasolabial crease were determined largely by the skeleton in rest, implying the latter can be altered by orthopedic or orthodontic correction and the former better improved by cosmetic procedures to improve the beauty of smile.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Stomatology, Guangzhou 510055, P. R. China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Lin
authors.affiliation: Department of Oral and Maxillofacial Surgery, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Stomatology, Guangzhou 510055, P. R. China.
authors.forename: Han
authors.initials: H
authors.lastname: Lin
authors.affiliation: Department of Orthodontic, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Stomatology, Guangzhou 510055, P. R. China.
authors.forename: Qiuping
authors.initials: Q
authors.lastname: Lin
authors.affiliation: Department of Medical Statistics and Epidemiology, School of Public Health, Sun Yat-sen University, Guangzhou 510055, P. R. China.
authors.forename: Jinxin
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Oral and Maxillofacial Surgery, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Stomatology, Guangzhou 510055, P. R. China.
authors.forename: Ping
authors.initials: P
authors.lastname: Zhu
authors.affiliation: School of Data and Computer Science, Guangdong Provincial Key Laboratory of Computational Science, Sun Yat-sen University, Guangzhou 510275, P. R. China.
authors.forename: Yao
authors.initials: Y
authors.lastname: Lu
authors.affiliation: Department of Medical Statistics and Epidemiology, School of Public Health, Sun Yat-sen University, Guangzhou 510055, P. R. China.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Zhao
authors.affiliation: Department of Orthodontic, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Stomatology, Guangzhou 510055, P. R. China.
authors.forename: Jiahong
authors.initials: J
authors.lastname: Lv
authors.affiliation: Division of Dentistry and Orthodontics, Children's Hospital Los Angeles, 4650 Sunset Blvd, #116 Los Angeles, CA 90027.
authors.forename: Mln Kyeong
authors.initials: MK
authors.lastname: Lee
authors.affiliation: Department of Orthodontic, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Stomatology, Guangzhou 510055, P. R. China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Xu
mesh_terms: D004954:Esthetics; D005145:Face / Q000033:anatomy & histology* / Q000601:surgery; D005149:Facial Expression; D006801:Humans; D008437:Maxilla / Q000033:anatomy & histology*; D019651:Plastic Surgery Procedures; D012904:Smiling