骨种植钉前牵引对骨性Ⅲ类错患者软硬组织侧貌的影响

目的研究采用骨种植钉前牵引对骨性Ⅲ类错患者软、硬组织侧貌的改变。方法选取18例需行前牵引矫治的生长发育期骨性Ⅲ类错患者,采用双侧上颌颧牙槽嵴植入骨种植钉配合面框式前牵引,平均治疗时间为9个月,力值为（3.5±0.1）N。治疗前后头影测量采用Legan&Burstone软组织分析法以及相关硬组织测量,分析比较患者治疗前后软、硬组织变化情况。结果所有患者Ⅲ类错均得到改善,鼻底趋于丰满,颏部顺时针旋转,侧貌由凹面型变为直面型,下唇突度减小,软组织上下面高比、鼻唇角、上唇突度及颏唇沟深度无明显变化。上前牙无明显变化,下前牙舌倾,上颌骨向前生长,A点前移,SNA、ANB增大;SNB减小,下颌骨顺时针旋转。结论骨种植钉前牵引可促进上颌生长,使面中份丰满,且对上颌前牙轴倾度无影响,从而纠正骨性Ⅲ类错。

Soft and hard tissue changes after maxillary protraction with skeletal anchorage implant in treatment of Class III malocclusion

Objective To evaluate the soft profile and hard tissue changes after maxillary protraction with skeletal anchorage implant in treatment of Class Ⅲ malocclusion during growth period.Methods 18 patients with skeletal Class Ⅲ malocclusion were treated with maxillary protraction for about 9 months,(3.5±0.1) N,with skeletal anchorage im-plant and face mask.Cephalometric records were analyzed to assess the changes of maxillo-facial structure of the hard and soft tissue before and after treatment.Results All patients’ Class Ⅲ profiles were corrected.Maxillary growth increased,chin clockwise rotated,facial convexity angle increased,lower lip protrusion decreased.Facial vertical height ratio,nasolabial angle,upper lip protrusion and mentolabial sulcus changed unconspicuously.Upper incisors kept in sites,lower incisor upright,maxilla moved forwards.SNA,ANB significantly increased.SNB decreased and the mandible clockwise rotated.Conclusion The maxilla is effectively protracted without significant rotation by using skeletal an-chorage implant.The undesired effects of conventional protraction therapies,such as labial tilt of upper anterior teeth and extrusion of the maxillary molars,are reduced or eliminated with skeletal anchorage implant.These effects can con-spicuously correct profiles of the patients with skeletal Class Ⅲ malocclusion,make the profile more harmonious and aesthetic.