A preliminary study on alveolar bone condition around mandibular incisors in adults with skeletal Class III malocclusion using CBCT

Abstract

Objective To study the morphology of alveolar bone around the mandibular incisors in adult patients with skeletal Class Ⅲ malocclusion.Methods The sample consisted of 17 patients with skeletal Class Ⅲ malocclusion and 10 normal occlusion subjects.TheCBCT images covering the region ofmandibular incisors were obtained and the data were measured and analyzed.Results ① Alveolar bone thickness(LA+LP3.3±0.6 mm) were thinner than normal groups.Root apex was closer to labial cortical bone than lingual (0.8±0.4 mm)(P＜0.01); ② The vertical alveolar bone level,especially at the labial side (LAH5.2 ± 1.3 mm) were significantly reduced than normal group (P＜0.01); ③ There were statistically correlations between the mandibular incisors inclination and the alveolar bone thickness,the alveolar bone level at the labial side,the distance between apex to labial bone.Conclusions In skeletal Class Ⅲ malocclusion adults,the alveolar bone thickness was thinner and the vertical alveolar level at the labial side was lower than normal occlusion ones.They were all correlated with the inclination of lower incisors.Alveolar bone morphology should be considered during lower incisor movements. Key words: Skeletal class Ⅲ malocclusion; CBCT; Alveolar bone morphology; Mandibular Incisor