골격성 부정교합의 분류에 따른 상악 중절치 치근과 절치관 사이의 거리 및 절치관의 형태에 관한 연구

Abstract

I. Introduction It is important to determine the position of the maxillary central incisor in orthodontic treatment. If it contacts or invades the incisive canal during the orthodontic treatment, resorption of the root can occur. The aim of this study was to evaluate the proximity between incisive canal and the root of the maxillary central incisor according to skeletal malocclusion by using cone-beam computed tomography (CBCT). II. Materials and Methods The study was performed on CBCT images and lateral cephalometric analysis was performed on all images. Skeletal malocclusion was classified into Class I, Class II, and Class III based on ANB angle. The distance between the maxillary central incisor and incisive canal was evaluated at two different vertical levels: 2 mm superior to the labial cementoenamel junction (L1) and 4 mm superior to the labial cementoenamel junction of the maxillary central incisor (L2). III. Results In all skeletal malocclusion groups, the distance between the incisive canal and the maxillary central incisor root was closer at L1 than L2 and the difference was statistically significant. At L1 level, in the case of skeletal Class II malocclusion, the distance to the incisive canal was closer than that of Class I (P = 0.013) or Class III (P = 0.008). At L2 level, the group with skeletal Class II malocclusion had a closer distance from the incisive canal than the group with Class III malocclusion (P = 0.039). IV. Conclusion In the case of skeletal Class II malocclusion, a large amount of retraction of maxillary incisors is frequently performed with the extraction of maxillary premolars as a camouflage treatment. In patients with skeletal Class II malocclusion, it will be more important to understand the distance between the root of the maxillary central incisor and incisive canal using CBCT to plan orthodontic treatment. Key words: Incisive canal; Maxillary central incisor; Malocclusion classification; Cone-beam computed tomography