3D Image Study of Morphology, Surgical Planning and Treatment of Facial Asymmetry

Dentofacial anomaly is a common facial deformity requiring treatment to prevent functional and psychosocial complications. Among our practice, one of the dentofacial anomalies, facial asymmetry especially those associated different bilateral face projections, is the most difficult and the result is usually suboptimal.. Classical treatment of dentofacial anomalies needs combined orthodontic/surgical treatment. Due to the limitation of traditional cephalometry methods, following problems were frequently encountered during surgical planning: 1. Lack of reliable reference line on posterioanterior cephalogram. 2. Duplicated bilateral structure on lateral cephalogram. 3. No information of posterioranterior projection on bilateral face. Cone Beam CT (CBCT) is a new dental roentgenologic diagnostic tool provides similar function of conventional CT but less radiation exposure in head and neck region. We organize this study to use the 2D and 3D images from CBCT scan to study morphologic characteristics of facial asymmetry and the methods for accurate surgical treatment. Material and Methods CBCT scanning would be performed in both study group of facial asymmetry and control group to acquired the necessary images of facial skeleton (T1). 3D mesh model of facial skeleton could be generated by 3D visualization software. Locating several anatomical landmarks and linear measurement would be performed on 3D model to describe the geometry of facial skeleton studied. Study group would be treated with traditional orthodontic/surgical methods and followed with another two CBCT scan, immediately after operation(T2) and finish of whole treatment (T3). A virtual surgical results (T2') would be created with image software by the pre-operative planning as predicted result. These measurement woule be compared between study group (T1) and control group for severity, between different time (T1 vs T2 ,T2 vs T3) to understand the surgical change and long term stability and also between real and virtual surgery (T2 vs T2') to understand difference between planned surgery and real result. Anticipated Accomplishment and Results The goal of this study is to use 3D computer image technique to study the morphology of facial asymmetry and the correct planning algorithm in treatment based on the deformed geometry. We hope to build a norm database of 3D cephalometry and 3D image model of Taiwanese adult that could be applied in all apsects, to clarify morphological characteristics of facial asymmetry and improve the treatment algorithm as well as surgical result.

Project ID:PC9709-0456
External Project ID:NSC97-2314-B182-021