Cone-beam CT analysis of occlusal planes between different vertical skeletal types of adult class Ⅱ malocclusions in Shandong province / 解剖学报

ABSTRACT

[Abstract] Objective To investigate the cant of the occlusal planes in Chinese adult class Ⅱ malocclusions with hypodivergent, normodivergent, and hyperdivergent facial vertical patterns using cone-beam CT. Methods The descriptive, cross-sectional study evaluated 123 cephalogram from CBCT(CCB) of patients in Department of Orthodontics, the Affiliated Hospital of Qingdao University. According to cephalometric analysis, 89 Chinese adult class Ⅱ patients were divided into three groups according to the angle between FH-MP and the angle between SN-MP. In comparison, 34 Class I normodivergent malocclusions individuals were selected as the control group. Comparing the cephalometric result between 4 groups. Results As expected,the hyperdivergent group had steeper anterior occlusal planes(14. 73±3. 76) . and posterior occlusal planes(21. 42±5. 77)., there was a significant statistical difference between the hyperdivergent group and other 2 groups in class Ⅱ patients (P<0. 05). The height of maxillary second molar increased from high angle group to low angle group (P<0. 01). Conclusion There are different characters of the occlusal planes in varied vertical facial pattern. The inclinations of anterior and posterior occlusal planes in Chinese class Ⅱ hyperdivergent group were steeper than other 3 groups. The difference of posterior occlusal plane inclination is mainly caused by the height of maxillary second molar.