Comparison of the effects of modified muscle agonists and Twin-block orthodontic appliances in the treatment of skeletal ClassⅡmandibular retraction deformity

doi:10.19439/j.sjos.2026.03.011

Abstract

Abstract: PURPOSE: To compare the effects of modified muscle agonist and Twin-block orthodontic appliance in the treatment of skeletal ClassⅡmandibular retraction deformity. METHODS: A total of 108 patients with skeletal ClassⅡ mandibular retraction deformity admitted to 904th Hospital, Joint Logistics Support Force, Chinese People's Liberation Army from March 2021 to June 2024 were selected and divided into 2 groups according to the random number table method, with 54 cases in each group. The control group was treated with Twin-block orthodontic appliance, while the experimental group was treated with modified muscle activator. The treatment effects were compared between the two groups. RESULTS: The corrective effect of the experimental group was significantly better than that of the control group (P<0.05). After treatment, the hard and soft tissue indicators and upper airway indicators in the experimental group were significantly better than those in the control group (P<0.05). The smile index and parabuccal space ratio of the experimental group were significantly lower than those of the control group, and the symmetry of the smile was significantly higher than that of the control group (P<0.05). The incidence of complications and the recurrence rate one year after treatment in the experimental group were significantly lower than those in the control group (P<0.05). CONCLUSIONS: Compared with Twin-block orthodontic appliance, modified muscle agonist has significant effect in correcting patients with skeletal ClassⅡmandibular retraction deformity. It can improve the smiling aesthetic index of patients, alleviates upper airway stenosis, and has a lower incidence of complications.

Key words: Modified muscle agonist, Twin-block orthodontic appliances, Skeletal Class Ⅱ mandibular retraction deformity

CLC Number:

R783.5

Zhang Yajun, Wang Hong, Wu Meng. Comparison of the effects of modified muscle agonists and Twin-block orthodontic appliances in the treatment of skeletal ClassⅡmandibular retraction deformity[J]. Shanghai Journal of Stomatology, 2026, 35(3): 288-293.

References

[1] Fadel R, Nicot R, Schlund M, et al.Simultaneous man dibular anterior segmental osteotomy and genioplasty: a novel technique[J]. J Craniofac Surg, 2023, 34(3): 1064-1066.
[2] 陈宏吉, 宋娟, 邓末宏. 舌系带成形术联合Twin-block矫治器治疗生长发育期下颌后缩患者的效果[J]. 实用医学杂志, 2025, 41(9): 1352-1360.
[3] 高莹, 于向华, 杨丽娜, 等. 前导式双垫对生长发育高峰期后骨性Ⅱ类下颌后缩的疗效[J]. 中国临床医学, 2023, 30(3): 502-508.
[4] 冯妍, 张良, 刘浩, 等. 改良肌激动器治疗青少年骨性Ⅱ类上气道改善的CBCT研究[J]. 河北医科大学学报, 2022, 43(6): 702-705, 726.
[5] Feng Q, Jiang F, Wang H, et al.Evaluation of modified clear Twin block aligner in treating adolescents with skeletal ClassⅡmalocclusion: a two-centre cephalometric study[J]. Orthod Craniofac Res, 2024, 27(4): 665-673.
[6] Khan MI, Neela PK, Unnisa N, et al.Dentoskeletal effects of Twin block appliance in patients with Class II malocclusion[J]. Med Pharm Rep, 2022, 95(2):191-196.
[7] 邹冰爽. 现代口腔正畸治疗学[M]. 北京: 人民卫生出版社, 2011: 26-27.
[8] 杨宇虹, 张静, 孙留振, 等. Twin-block功能矫治器与肌激动器对安氏Ⅱ类下颌后缩的矫治效果对比[J]. 临床医学工程, 2025, 32(3): 279-282.
[9] 赵健, 史舒雅, 李超群, 等. 颧牙槽嵴下微种植体对骨性Ⅱ类错畸形患者微笑美学效果的影响[J]. 口腔医学研究, 2024, 40(11):967-971.
[10] 张明欣, 马艳宁, 金作林. 隐形功能矫治在青少年骨性Ⅱ类下颌后缩患者治疗中的研究进展[J]. 中华口腔医学研究杂志电子版, 2024, 18(1): 61-64.
[11] Huo B, Che X, Li X.Timing of early correction of mandibular hypoplasia in skeletal Class Ⅱ malocclusion: a review[J]. J Clin Pediatr Dent, 2023, 47(6): 11-20.
[12] Alhammadi MS, Qasem AAA, Yamani AMS, et al.Skeletal and dentoalveolar effects of Class Ⅱ malocclusion treatment using bi-maxillary skeletal anchorage: a systematic review[J]. BMC Oral Health, 2022, 22(1): 339.
[13] Ding L, Chen R, Liu J, et al.The effect of functional mandibular advancement for adolescent patients with skeletal ClassⅡmalocclusion on the TMJ: a systematic review and meta-analysis[J]. BMC Oral Health, 2022, 22(1): 51.
[14] Sun J, Zhu H, Lu C, et al.Temporomandibular joint disc repositioning and occlusal splint for adolescents with skeletal ClassⅡmalocclusion: a single-center, randomized, open-label trial[J]. BMC Oral Health, 2023, 23(1): 694.
[15] Huang W, Dong L, Yu S, et al.Stress distribution of the modified clear Twin-block aligner on the temporomandibular joint, alveolar bone and teeth: a finite element analysis[J]. Int Orthod, 2023, 21(4): 100815.
[16] Duan J, Xia W, Yang K, et al.The efficacy of Twin-block appliances for the treatment of obstructive sleep apnea in children: a systematic review and meta-analysis[J]. Biomed Res Int, 2022, 2022:3594162.
[17] Bastiani C, Bellini-Pereira SA, Aliaga-Del Castillo A, et al. Twin-block and mandibular anterior repositioning appliances effects in Class II malocclusion correction[J]. Am J Orthod Dentofacial Orthop, 2023, 163(2):181-190.
[18] Lombardo EC, Lione R, Franchi L, et al.Dentoskeletal effects of clear aligner vs Twin block-a short-term study of functional appliances[J]. J Orofac Orthop, 2024, 85(5):317-326.
[19] 黄朝阳, 肖俐娟, 赵玲. 改良肌激动器矫治生长发育期安氏Ⅱ类1分类错畸形21例临床分析[J]. 广西医科大学学报, 2021, 38(7): 1448-1452.
[20] 黄飞, 陈倩, 张胜男. Pass矫治器与Twin-block功能矫治器联合自锁托槽在安氏Ⅱ类1分类错畸形中的矫正效果比较[J]. 中国现代医学杂志, 2025, 35(6): 6-11.