Khan Mahamad Irfanulla, Neela Praveen Kumar, Unnisa Nayeem, Jaiswal Ajit Kumar, Ahmed Nadeem, Purkayastha Abhik
Department of Orthodontics & Dentofacial Orthopedics, Oxford Dental College, Bangalore, India.
Department. of Orthodontics & Dentofacial Orthopaedics, Kamineni Institute of Dental Sciences, Narketpally, Andhra Pradesh, India.
Med Pharm Rep. 2022 Apr;95(2):191-196. doi: 10.15386/mpr-1989. Epub 2022 Apr 28.
Class II malocclusions are most commonly seen in orthodontic practice and in the recent times Twin Block appliance has been the most popular and widely used among removable functional appliances for the correction of Class II malocclusion in growing patients. The aim of this retrospective study was to evaluate the dentoskeletal effects produced by the Twin Block appliance for the correction of Class II division 1 malocclusion with retrognathic mandible.
Pre-treatment (T1) and post-treatment (T2) lateral cephalograms of 30 patients treated with Twin Block appliance (mean age = 10.8 ± 1.2 years) for the correction of class II division 1 malocclusion were compared with the 30 untreated class II control patients (mean age 11.2 ± 0.8 years) who did not undergo any treatment during this period. Both the groups were evaluated for the dentoskeletal changes using 24 angular and linear cephalometric measurements. The differences between the pre and post-treatment were calculated using a paired t-test.
The cephalometric analysis revealed that the Twin Block appliance stimulated mandibular growth and statistically significant differences were found between the two groups. Twin Block patients showed a statistically very high significant (p<0.001) increase in mandibular length (6.02 mm) compared with the control group (0.3 mm). "Headgear effect" on the maxilla, increase in lower anterior facial height, significant reduction of overjet, overbite and Class I molar relationship were achieved in the Twin Block group. However, no significant changes appeared in the control group.
The results of the present study conclude that the Twin Block appliance is effective in the treatment of Class II malocclusion and this is due to a combination of skeletal and dentoalveolar changes in both the arches.
安氏II类错牙合畸形在正畸临床中最为常见，近年来，双期阻断矫治器已成为矫治生长发育期患者安氏II类错牙合畸形的可摘功能矫治器中最受欢迎且应用最广泛的一种。本回顾性研究的目的是评估双期阻断矫治器对下颌后缩型安氏II类1分类错牙合畸形的牙颌面影响。
选取30例使用双期阻断矫治器矫治安氏II类1分类错牙合畸形的患者（平均年龄 = 10.8 ± 1.2岁）的治疗前（T1）和治疗后（T2）头颅侧位片，与30例未经治疗的安氏II类对照患者（平均年龄11.2 ± 0.8岁）进行比较，后者在此期间未接受任何治疗。两组均采用24项角度和线性头影测量指标评估牙颌面变化。治疗前后的差异采用配对t检验计算。
头影测量分析显示，双期阻断矫治器刺激了下颌生长，两组间差异有统计学意义。与对照组（0.3 mm）相比，双期阻断矫治器治疗组患者的下颌长度在统计学上有非常显著的增加（6.02 mm，p<0.001）。双期阻断矫治器组对上颌产生了“口外弓效应”，增加了下前牙区面部高度，显著减小了覆盖、覆牙合以及建立了I类磨牙关系。然而，对照组未出现显著变化。
本研究结果表明，双期阻断矫治器在治疗安氏II类错牙合畸形方面是有效的，这是由于上下牙弓的骨骼和牙牙槽骨变化共同作用的结果。
