片段弓在深覆矫治中的临床应用研究

Research of clinical application of segmented arch technique for deep overbite correction

目的:探讨片段弓矫治重度深覆牙合患者的作用机制及临床作用要点。方法:对16例成人重度深覆患者,用片段弓来打开咬合,并对咬合打开前后的硬软组织变化进行分析。结果:①戴用片段弓3～6个月(平均4.5月)后,覆牙合达到正常,切牙段出现整体压低,而对支抗后牙几乎无影响,上颌磨牙的角度、垂直距离与上颌切牙的角度均未改变。②压低上切牙时平均每月0.47mm,共压低了2.12mm,6～8周后可看见压低效果。③在观察期内,随着上中切牙的压低,上切牙唇下暴露量减少,上下唇间隙平均减小,并且上唇有下降趋势。结论:片段弓矫治深覆牙合主要依靠上下前牙的整体压低,因此片段弓适用于下颌平面角较大、前牙过长或前牙齿槽突发育过度、上下唇间隙过大、上切牙唇下暴露较多的重度深覆牙合患者。

Objective The purpose of this study was to investigate the efficiency of segmented arch technique in deep overbite correction. Methods A total of 16Ⅱ- Ⅲ degree deepbite female patients ,aged from 18 to 32 （average 22.3 years old）,were selected to be treated with segmented arch technique,The profile change were studied using the computer-aid X-ray cephalometric analysis.Periapical resorption was observed on periapical radiography.SPSS 10.0 statistical software was used to calculate means and standard deviation. Paired T-test was concluded to determine the statistical significance of the mean values,Ridit test was used to evaluate the degree of the periapical resorption. Results ①After segmented arch technique was used 3 to 6 months,overbite corrected,incisor segment was been intruded absolutely,while the angle of maxilla incisor and molar had no change,also had the vertical dimension of maxilla molar.So absolute intrusion of incisor was statistically significant,almost had no influence to the anchorage dental.② Maxillary incisor intruded 2.12mm,averaged 0.47ram every month,effect of intrusion can be observed after 6 to 8 months. ③soft tissue change During the period of observing time,with intrusion of maxilla ineisor,upperlip tended to come down, exposure of maxillary incisor under upperlip decreased,the distance between the upper lip stomion and the lower lip stomion with the lips in repose decreased.4.Periapical resorption had no statistical significance. Conclusion Segmented arch technique corrected overbite by intruded anterior tooth absolutely,Segmented arch technique was effective for the deep everbite patients with higher angle of SN-MP who induced by hypergenesis of anterior teeth and dental alveoli,and who has larger distance between the upper lip stomion and the lower lip stomion with the lips in repose;more exposure of maxillary incisor under upperJip; more exposure of .gingival.