Cone-beam computed tomography evaluation of the change of anterior alveolar bone height in Class II division 1 patients after orthodontic treatment

Abstract

Objective To evaluate the change of anterior alveolar bone height in Class Ⅱ division 1 patients after orthodontic treatment. Methods The sample consisted of 62 Class Ⅱ division 1 patients. They were divided into two groups, extraction group (11 males and 21 females, mean age 12.63±0.94 years) and non-extraction group (17 males and 13 females, mean age 12.33±1.24 years). The Cone-beam Computed Tomography (CBCT) images of pre-treatment and post-treatment were collected. The labial and the lingual (palatal) distance from Cementoenamel Junction (CEJ) to alveolar bone crest of the anterior teeth were measured before and after treatment. SPSS 20.0 software package was used for statistical analysis. Results The alveolar bone height loss in extraction group and non-extraction group reached 67.31% and 66.94%, respectively. The average bone height loss in extraction group and non-extraction group were (1.03±2.47) mm and (0.69±4.02) mm, respectively. For the lingual side of the upper incisors and lower anteriors, the average bone height loss in extraction group was much higher than in non-extraction group (P>0.05). However, for the labial side of the lower anteriors, the average bone height loss in non-extraction group was much higher than extraction group (P>0.05). Conclusions The anterior alveolar bone height in Class Ⅱ division 1 patients generally decreased after orthodontic treatment. The amount of decrease was closely correlated to tooth position, moving direction and moving range. Key words: Angle Class Ⅱ division 1 malocclusion; Orthodontic treatment; Alveolar bone height