A study of closed miniscrew anchorage in intrusion of mandibular incisors to correct deep overbite in adult patients

目的 评价微螺钉支抗闭合式牵引压低下颌切牙矫治成人深覆(牙合)的有效性.方法 选择20例符合纳入标准的成人深覆(牙合)患者,在下颌中切牙间切开黏膜,于下颌骨正中联合部位植入微螺钉一枚,并以结扎丝连接穿出黏膜形成牵引钩,加力进行下前牙压低治疗.正畸治疗前后分别拍摄头颅侧位片,并进行头影测量的分析比较.结果 20例患者矫治后覆(牙合)均达正常范围,平均减小4.0 mm(P＜0.001).下切牙抗力中心的垂直向变化值平均2.8mm,具有显著性意义(P＜0.001).同时,下切牙显著性唇向倾斜,L1/MP和L1/NB平均增加5.8°和2.3°,上下颌中切牙角显著性减小(P＜0.01).伴随切牙的压低和唇倾,(牙合)平面发生顺时针变化,治疗后MP/OP显著性减小3.5°(P＜0.001).而下颌磨牙在轴倾度和垂直向上均无显著性变化,下颌切牙压低治疗后未见显著根吸收现象.结论 应用微螺钉支抗取得压低下切牙的良好效果,是矫治成人深覆(牙合)的有效手段.Objective The purpose of this study is to investigate the effectiveness of the mandibular incisors intrusion by using closed miniscrew anchorage to correct the deep overbite in adult patients.Methods The sample comprised 20 adult patients with deep overbite who met the inclusion criteria.After surgical exposure of mandibular symphysis,one miniscrew was placed and closed up.Stainless steel ligature wire was tied with one end to miniscrew and the other end forming a cook exposed in oral cavity for later intrusion of mandibular incisors.Pre-and post-treatment cephalometric radiographs were measured and compared.Results All the patients had their deep overbite corrected,with an average decrease of 4 mm (P＜0.001).The resistant center of mandibular incisors was intruded 2.8 mm remarkably (P＜0.001).Meanwhile,significant labial proclination of the mandibular incisors were observed with increases in L1/MP and L1/NB (5.8° and 2.3°,respectively) and the decrease in Ul/L1 (P＜0.01).With lower incisor intrusion and inclination,occlusal plane showed clockwise rotation,and the post-treatment MP/OP decreased significantly by 3.5° (P＜0.001).The mandibular molars did not change significantly in inclination and vertical dimension.No significant root resorption of the incisors was found.Conclusions Intrusion of mandibular incisors through miniscrew anchorage could be used as an efficient method to correct deep overbite in adult patients.中国科技核心期刊(ISTIC)012-92