Salehi Parisa, Pakshir Hamid Reza, Hoseini Seyed Ali Reza
Orthodontic Research Center, Dept. of Orthodontics, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran.
Post graduate Specialist in Orthodontics, Member of Orthodontic Research Center, Dept. of Orthodontics, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran.
J Dent (Shiraz). 2015 Mar;16(1):22-9.
Orthodontists often find challenges in treating the anterior open bite and maintaining the results.
This retrospective study was aimed to evaluate the stability of corrected open bite in the retention phase during permanent dentition.
A total number of 37 patients, including 20 males and 17 females, with the mean age of 18±2.1 years at the beginning of the treatment were studied after correction of the anterior open bite. Overbites of the patients were measured from their lateral cephalograms before (T1), at the end (T2) and at least 3 years after the end of the treatment in the presence of their fixed retainers (T3).The mean overbite changes and the number of patients with open bite, due to treatment relapse, at T3 were calculated. The relationship between the pre-treatment factors and the treatment relapse was assessed at T1 and T2. Also the effects of treatment methods, extraction and adjunctive use of removable appliances on the post-treatment relapse were evaluated.
The mean overbite change during the post-treatment period was -0.46±0.7 mm and six patients (16.2%) had relapse in the follow-up recall. Cephalometric Jaraback index showed statistically significant, but weak correlation with overbite changes after the treatment (p= 0.035; r= -0.353). No significant difference was found between the extraction and non-extraction groups (p= 0.117) the use and the type of the removable appliances (p= 0.801).
Fixed retainers alone are insufficient for stabilizing the results of corrected open bite. The change of overbite in the retention phase could not be predicted from cephalometric measurements. Extraction and use of adjunctive removable appliance did not have any effect on the treatment relapse.
正畸医生在治疗前牙开合以及维持治疗效果方面常常面临挑战。
本回顾性研究旨在评估恒牙列保持期矫正后开合的稳定性。
对37例患者进行研究，其中男性20例，女性17例，治疗开始时平均年龄为18±2.1岁，均接受了前牙开合矫正。在治疗前（T1）、结束时（T2）以及治疗结束后至少3年佩戴固定保持器时（T3），通过头颅侧位片测量患者的覆合情况。计算T3时覆合的平均变化以及因治疗复发导致开合的患者数量。评估T1和T2时治疗前因素与治疗复发之间的关系。此外，还评估了治疗方法、拔牙以及可摘矫治器的辅助使用对治疗后复发的影响。
治疗后期间覆合的平均变化为-0.46±0.7mm，6例患者（16.2%）在随访复查时有复发。头影测量Jaraback指数显示与治疗后覆合变化具有统计学意义但较弱的相关性（p = 0.035；r = -0.353）。拔牙组与非拔牙组之间（p = 0.117）以及可摘矫治器的使用和类型之间（p = 0.801）未发现显著差异。
仅使用固定保持器不足以稳定矫正后开合的治疗效果。无法通过头影测量预测保持期覆合的变化。拔牙和使用辅助可摘矫治器对治疗复发没有任何影响。
