Compensation of upper first molar in skeletal class Ⅲ patients treated with orthodontic-surgical treatment
10.3760/cma.j.issn.1002-0098.2018.05.004
- VernacularTitle: 正畸-正颌联合治疗骨性Ⅲ类错畸形的上颌第一磨牙代偿特征初探
- Author:
Jie ZHANG
1
;
Huimin MA
2
;
Xiaotong LI
2
Author Information
1. Department of Orthodontics, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology, Beijing 100081, China (Present address: Department of Stomatology, Shenzhen Children's Hospital, Shenzhen Guangdong 518038, China)
2. Department of Orthodontics, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology, Beijing 100081, China
- Publication Type:Journal Article
- Keywords:
Malocclusion, Angle class Ⅲ;
Molar;
Imaging, three-dimensional;
Torque
- From:Chinese Journal of Stomatology
2018;53(5):307-311
- CountryChina
- Language:Chinese
-
Abstract:
Objectives:To investigate the compensation of upper first molar in adult skeletal class Ⅲ patients.
Methods:The sample consisted of 48 skeletal class Ⅲ patients with orthodontic-surgical treatment from February 2011 to January 2015 in Peking University School and Hospital of Stomatology. They were allocated into 2 groups based on extraction, 28 patients in extraction group and 22 patients in non-extraction group. Dental casts were taken before and after treatment, and all the casts were scanned with a computer-assisted three-dimensional (3D) scanning system. Acquired 3D data were analyzed by Rapidform 2006. The tip and torque of the upper first molar were measured and analyzed.
Results:The tip and torque of the upper first molar in the skeletal class Ⅲ patients after treatment had no difference between extraction group and non-extraction group (P=0.150, P=0.144). The torque of upper first molar in extraction group [-3.32° (-5.10°, 1.16°)] before treatment was bigger than that in non-extraction group [-6.94° (-13.06°, -0.42°)] (P=0.005), and the inclination of upper first molar in extraction group was more obvious.
Conclusions:In skeletal class Ⅲ patients, the upper first molar inclined buccally to compensate the discrepancy and extraction was usually necessary for decompensation.
