Luiz A G Barbosa1, Eustaquio Araujo2, Rolf G Behrents2, Peter H Buschang3. 1. Private Practice, Coppell, Tex. 2. Department of Orthodontics, Saint Louis University, St Louis, Mo. 3. Department of Orthodontics, Baylor College of Dentistry, Texas A&M Health Science Center, Dallas, Tex. Electronic address: phbuschang@bcd.tamhsc.edu.
Abstract
INTRODUCTION: Our objective was to evaluate the craniofacial growth of subjects with untreated Class II Division 2 malocclusion. METHODS: A mixed longitudinal sample of 39 white Class II Division 2 subjects was analyzed at 5 time points: T1 (6 or 7 years), T2 (9 or 10 years), T3 (12 or 13 years), T4 (15 or 16 years), and T5 (18 or 19 years). They were compared with an age- and sex- matched sample of Class I controls. Seventeen measurements (12 angular, 5 proportional) were computed. Multilevel modeling procedures were used to statistically describe the growth changes and to evaluate group differences. RESULTS: There were no group differences in the relative sizes and anteroposterior positions of the jaws during childhood, adolescence, or early adulthood. Subjects with Class II Division 2 malocclusion demonstrated significantly (P <0.05) smaller mandibular plane angles, smaller palatal-to-mandibular plane angles, larger posterior-to-anterior facial height ratios, smaller gonial angles, smaller cranial base angles, larger interincisal angles, and more retroclined maxillary incisors than did the Class I subjects. The hypodivergent patterns were established early and became more pronounced over time. Group differences in the mandibular plane angle, palatal-to-mandibular plane angle, gonial angle, interincisal angle, and maxillary incisor-to-cranial base angle, as well as the posterior-to-anterior facial height ratio all increased over time; the difference in the cranial base angle remained unchanged over time. Retroclination of the maxillary incisors occurred primarily during the early mixed dentition. CONCLUSIONS: Subjects with Class II Division 2 malocclusion are more hypodivergent and have more upright maxillary incisors than do subjects with Class I occlusion. Hypodivergence establishes itself early and increases progressively through early adulthood; maxillary incisor retroclination occurs early.
INTRODUCTION: Our objective was to evaluate the craniofacial growth of subjects with untreated Class II Division 2 malocclusion. METHODS: A mixed longitudinal sample of 39 white Class II Division 2 subjects was analyzed at 5 time points: T1 (6 or 7 years), T2 (9 or 10 years), T3 (12 or 13 years), T4 (15 or 16 years), and T5 (18 or 19 years). They were compared with an age- and sex- matched sample of Class I controls. Seventeen measurements (12 angular, 5 proportional) were computed. Multilevel modeling procedures were used to statistically describe the growth changes and to evaluate group differences. RESULTS: There were no group differences in the relative sizes and anteroposterior positions of the jaws during childhood, adolescence, or early adulthood. Subjects with Class II Division 2 malocclusion demonstrated significantly (P <0.05) smaller mandibular plane angles, smaller palatal-to-mandibular plane angles, larger posterior-to-anterior facial height ratios, smaller gonial angles, smaller cranial base angles, larger interincisal angles, and more retroclined maxillary incisors than did the Class I subjects. The hypodivergent patterns were established early and became more pronounced over time. Group differences in the mandibular plane angle, palatal-to-mandibular plane angle, gonial angle, interincisal angle, and maxillary incisor-to-cranial base angle, as well as the posterior-to-anterior facial height ratio all increased over time; the difference in the cranial base angle remained unchanged over time. Retroclination of the maxillary incisors occurred primarily during the early mixed dentition. CONCLUSIONS: Subjects with Class II Division 2 malocclusion are more hypodivergent and have more upright maxillary incisors than do subjects with Class I occlusion. Hypodivergence establishes itself early and increases progressively through early adulthood; maxillary incisor retroclination occurs early.
Authors: Miguel Pais Clemente; André Moreira; Catarina Morais; José Manuel Amarante; Afonso Pinhão Ferreira; Joaquim Mendes Journal: Int J Environ Res Public Health Date: 2021-04-19 Impact factor: 3.390