Treatment of adult Class III malocclusions with orthodontic therapy or orthognathic surgery: Receiver operating characteristic analysis

• Published in: American journal of orthodontics and dentofacial orthopedics Vol. 139; no. 5; pp. e485 - e493
• Main Authors: Tseng, Yu-Chuan, Pan, Chin-Yun, Chou, Szu-Ting, Liao, Chen-Yi, Lai, Sheng-Tsung, Chen, Chun-Ming, Chang, Hong-Po, Yang, Yi-Hsin
• Format: Journal Article
• Language: English
• Published: United States Mosby, Inc 01.05.2011
• Subjects: Adolescent; Adult; Area Under Curve; Cephalometry - statistics & numerical data; Chin - pathology; Dentistry; Discriminant Analysis; Female; Humans; Incisor - pathology; Male; Malocclusion, Angle Class III - surgery; Malocclusion, Angle Class III - therapy; Mandible - pathology; Maxilla - pathology; Nasal Bone - pathology; Orthodontics, Corrective - statistics & numerical data; Orthognathic Surgical Procedures - statistics & numerical data; Retrospective Studies; ROC Curve; Sella Turcica - pathology; Sensitivity and Specificity; Treatment Outcome; Young Adult
• ISSN: 0889-5406; 1097-6752; 1097-6752
• DOI: 10.1016/j.ajodo.2010.12.014

The aim of this study was to distinguish between orthodontic patients with skeletal Class III malocclusions requiring surgery and those not requiring surgery by conducting a receiver operating characteristic analysis of cephalometric variables. We used lateral cephalometric radiographs of 80 subjects (40 nonsurgical and 40 surgical patients) with Class III malocclusions and obtain 25 cephalometric measurements using computerized cephalometry. Of these, 14 measurements showed statistically significant differences between the 2 groups. Receiver operating characteristic analysis was used to determine the ability of the 14 cephalometric measurements in distinguishing between the 2 groups. Six statistically validated and clinically relevant measurements were used to obtain the optimum discriminant effectiveness. For a Class III malocclusion patient with any 4 of these 6 measurement criteria, the sensitivity was 88% and the specificity was 90% in determining the need for surgical treatment: overjet, ≤–4.73 mm; Wits appraisal, ≤–11.18 mm; L1-MP angle, ≤80.8°; Mx/Mn ratio, ≤65.9%; overbite, ≤–0.18 mm; and gonial angle, ≥120.8°. We selected 6 cephalometric measurements as the minimum number of discriminators required to obtain the optimum discriminant effectiveness of diagnosis between surgical and nonsurgical treatment of skeletal Class III malocclusions.