Dauravu Liju Marcely, Vannala Venkataramana, Arafath Mohamed, Singaraju Gowri Sankar, Cherukuri Sreekanth A, Mathew Anju
Senior Lecturer, Department of Orthodontics, Mar Baselios Dental College , Kothamangalam, Kerala, India .
Professor, Department of Orthodontics, Panineeya Mahavidhyalaya Institute of Dental Sciences , Kamalanagar, Hyderabad, Andhra Pradesh, India .
J Clin Diagn Res. 2014 Dec;8(12):ZC81-4. doi: 10.7860/JCDR/2014/10747.5354. Epub 2014 Dec 5.
The main reason for seeking orthodontic treatment for Class II malocclusions is aesthetic improvement. Growth modification treatment procedures offer better results for a patient with significant potential growth.
The aim of this cephalometric clinical study was to distinguish skeletal and dental corrections on skeletal class II division I growing subjects with Twin Block therapy (TB) and the changes were assessed using SO-analysis by Pancherz.
Strict diagnostic protocol viz. growing individuals with horizontal growth pattern, skeletal class II due to retrognathic mandible with positive VTO, bilateral class II molar relation, minimal crowding in either arch or overjet more than 5mm was used. Out of 28 selected cases,17 patients received TB therapy and 11 patients were maintained as control group. Standard removable TB appliances with lower incisor capping were delivered to treatment group. The horizontal advancement was about 8mm and 2-3mm vertical opening between the upper and lower central incisors were maintained for all the cases. The mean time interval between the initial (T1)and post treatment (T2) cephalograms of Twin-Block group was 11 month,with a range of 8 month to 13 month. In the control group, the mean time interval between the first (C1)and second (C2) cephalometric films was 12 month,with a range of 10 month to 14 month.T1and T2 cephalograms were traced and S-O analysis was used to segregate dental and skeletal effects.
SPSS software was used for statistical analysis.
Skeletal Changes: In this study, the mean movement of maxilla was 0.67mm which represents significant restriction of forward maxillary growth in contrast to control groups. Dental Changes: In this study the maxillary molars appear to move distally with a mean value of 0.13mm. Comparing this to the movement of maxillary jaw base itself, maxillary distal movement of molar is less. But still it contributes to Class II correction.
The overjet reduction and molar relation correction are more skeletal in nature.
寻求正畸治疗安氏II类错牙合的主要原因是改善美观。生长改良治疗程序对具有显著生长潜力的患者能取得更好的效果。
本头影测量临床研究的目的是区分使用双期阻断矫治器（TB）治疗的生长发育期安氏II类1分类患者的骨骼和牙齿矫正情况，并采用潘彻兹的S-O分析法评估其变化。
采用严格的诊断标准，即具有水平生长型的生长发育期个体，因下颌后缩导致的安氏II类错牙合且VTO为正值，双侧II类磨牙关系，牙弓轻度拥挤或覆盖超过5mm。在28例入选病例中，17例患者接受TB治疗，11例患者作为对照组。给治疗组佩戴带有下切牙帽的标准可摘式TB矫治器。所有病例的水平前导约为8mm，上下中切牙之间保持2 - 3mm的垂直打开。双期阻断矫治器组初始（T1）和治疗后（T2）头影测量片之间的平均时间间隔为11个月，范围为8个月至13个月。对照组中，第一次（C1）和第二次（C2）头影测量片之间的平均时间间隔为12个月，范围为10个月至14个月。对T1和T2头影测量片进行描图，并采用S - O分析法分离牙齿和骨骼效应。
采用SPSS软件进行统计分析。
骨骼变化：在本研究中，上颌骨的平均移动量为0.67mm，这表明与对照组相比，上颌向前生长受到显著限制。牙齿变化：在本研究中，上颌磨牙似乎向远中移动，平均值为0.13mm。与上颌颌骨基部自身的移动相比，磨牙的上颌远中移动较小。但它仍然有助于安氏II类错牙合的矫正。
覆盖减小和磨牙关系矫正本质上更多是骨骼性的。
