[CBCT study on the measurement of occlusal plane and molars in adolescent patients with Class Ⅱ subdivision malocclusion].

Purpose: To study the CBCT imaging features of occlusal plane inclination, molar inclination, and molar height in adolescent patients with Class Ⅱ subdivision malocclusion, in order to provide reference for clinical diagnosis and treatment.

Methods: A total of 80 adolescent patients with malocclusion admitted to Suzhou Stomatological Hospital from January 2019 to December 2022 were selected, including 40 cases of Class Ⅱ subdivision malocclusion as the experimental group and 40 cases of Class Ⅰ malocclusion as the control group. The angles of the anterior, posterior and maxillary occlusal planes, as well as the inclination of the upper and lower molars in the mesial and distal direction, the inclination of the buccal and lingual direction, and the height of the molars were analyzed based on CBCT data. SPSS 23.0 software package was used for data analysis.

Results: There were significant differences in the angles of the neutral and distal anterior, posterior and maxillary occlusal planes, as well as the height of the upper and lower molars between the experimental group of patients with Class Ⅱ subdivision malocclusion(P＜0.05); There was no significant difference in the inclination of the upper and lower molars in the mesial and distal direction, as well as in the inclination of the buccal and lingual directions(P＞0.05). There was no significant difference in the comparison of left and right measurements in the control group(P＞0.05). The angles of the anterior, posterior and maxillary occlusal planes in the experimental group were significantly negatively correlated with the inclination of the maxillary molars in the mesiodistal and buccal lingual direction(P＜0.01), and negatively correlated with the height of the molars(P＜0.05).

Conclusions: Patients with Class Ⅱ subdivision malocclusion may have differences in the angles of the posterior, anterior, and maxillary occlusal planes, as well as the height of the upper and lower molars, compared to Class Ⅰ malocclusion patients. In clinical orthodontic treatment, it is necessary to be vigilant for such patients, trying to choose appropriate treatment opportunities, and reasonable treatment plans to prevent malocclusion from developing towards a more severe direction.