Transverse dimensional changes following Twin-Block and slow maxillary expansion therapy in adolescents with Angle Class Ⅱ division 1 malocclusion: a cone-beam computed tomography study
10.12016/j.issn.2096-1456.202660051
- Author:
PAN Yinti
1
;
QIN Changtao
2
,
3
;
ZHENG Yi
1
;
GUO Anjie
1
;
SUN Xin
1
;
CHEN Zhixing
1
;
MO Shuixue
1
Author Information
1. Department of Orthodontics, College & Hospital of Stomatology, Guangxi Medical University & Guangxi Clinical Research Center for Craniofacial Deformity & Guangxi Key Laboratory of Oral and Maxillofacial Rehabilitation and Reconstruction
2. East Daxue Road Comprehensive Department, College & Hospital of Stomatology, Guangxi Medical University
3. Guangxi Clinical Research Center for Craniofacial Deformity & Guangxi Key Laboratory of Oral and Maxillofacial Rehabilitation and Reconstruction
- Publication Type:Journal Article
- Keywords:
Twin-Block appliance;
slow maxillary expansion;
Angle Class Ⅱ division 1 malocclusion;
two-phase treatment;
dental arch width;
basal bone width;
buccolingual inclination;
transverse width;
cone-beam computed tomography
- From:
Journal of Prevention and Treatment for Stomatological Diseases
2026;34(5):471-482
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the effects of a Twin-Block appliance combined with slow maxillary expansion (SME) on transverse dental and skeletal parameters in adolescent patients with Angle Class Ⅱ division 1 malocclusion, and to provide a reference for clinical orthodontic practice.
Methods:This retrospective study was approved by the Institutional Ethics Committee. A total of 21 adolescents with Class Ⅱ division 1 malocclusion who underwent two-phase treatment with a Twin-Block appliance combined with SME at the Department of Orthodontics, College & Hospital of Stomatology, Guangxi Medical University, in 2021 to 2023 were consecutively enrolled. In the first phase, a functional appliance was used to coordinate the skeletal relationship between the maxilla and mandible by leveraging growth potential. In the second phase, a fixed appliance was employed for fine adjustments of the dental arches based on the specific condition. Cone-beam computed tomography (CBCT) scans were obtained before treatment (T0) and after the first phase of functional correction (T1). Transverse measurements at the first molar region, including molar buccolingual inclination, dental arch width, and basal bone width, were performed using Dolphin 3D Imaging software. Changes between T0 and T1 were statistically analyzed.
Results:After the first phase of treatment, the left and right maxillary first molars showed a significant increase in buccal inclination by 5.47° ± 1.38° and 5.35° ± 1.61°, respectively (P<0.001). The arch width in the maxillary first molar region also increased by (2.68 ± 1.14) mm, and the basal bone width increased by (1.14 ± 1.24) mm (all P<0.001). The proportion of skeletal expansion accounted for an average of 42.86%, while dental expansion accounted for 57.14%. No statistically significant changes were observed in any mandibular transverse measurements (all P>0.05).
Conclusion:In adolescent patients with Angle Class Ⅱ division 1 malocclusion accompanied by maxillary transverse deficiency, Twin-Block appliance combined with SME can effectively expand maxillary dental arch and basal bone width while improving sagittal relationship, thereby correcting transverse discrepancy. The maxillary width changes were predominantly dental.
- Full text:2026052015364634693Twin-Block联合上颌慢速扩弓治疗对青少年安氏Ⅱ类1分类患者牙颌横向变化的CBCT研究.pdf
