title: Cephalometric predictors of long-term stability in the early treatment of Class III malocclusion.
abstract: The aim of this study was to examine the differences in the early craniofacial morphology of Class Ill malocclusions. Lateral cephalograms of 45 subjects with a Class III malocclusion and an anterior crossbite in the deciduous or mixed dentition were examined before treatment, after treatment, and during the long-term retention stage. The anterior crossbites of all patients were corrected after a series of orthodontic treatments. After a mean follow-up period of 5.7 years, all the subjects were reevaluated and divided into three groups according to the final occlusal status: good, fair, and poor occlusal stability. Twenty cephalometric variables on the pretreatment lateral cephalograms were analyzed by one-way analysis of variance and discriminant analysis to identify the key determinants for discriminating among the three groups. Among the 20 variables, 11 showed statistical significance. Generally, the subjects with a smaller gonial angle and a more hypodivergent skeletal pattern had good prognosis after the early treatment of Class III malocclusion. When the AB to mandibular plane angle and N-perpendicular to point A were selected in discriminant analysis, the AB to mandibular plane angle was the most significant variable. Discriminant analysis showed a relatively high degree of correct classifications of the patients with early Class III malocclusion. In particular, discriminant analysis showed the highest accuracy (93.3%) when predicting a poor prognosis.
authors.affiliation: Department of Orthodontics, College of Dentistry, Seoul National University, Seoul, South Korea.
authors.forename: Young-Min
authors.initials: YM
authors.lastname: Moon
authors.forename: Sug-Joon
authors.initials: SJ
authors.lastname: Ahn
authors.forename: Young-Il
authors.initials: YI
authors.lastname: Chang
mesh_terms: D000293:Adolescent; D000367:Age Factors; D000704:Analysis of Variance; D002508:Cephalometry; D002648:Child; D016002:Discriminant Analysis; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008313:Malocclusion, Angle Class III / Q000000981:diagnostic imaging* / Q000628:therapy*; D009971:Orthodontics, Corrective; D011237:Predictive Value of Tests; D011379:Prognosis; D011859:Radiography; D012008:Recurrence