骨性Ⅲ类错（牙合）患者单、双颌手术方案选择的临床研究

Surgery decision in adult patients with Skeletal Class Ⅲ malocclusion： Mandibular only or Bimaxillary orthognathic surgery

目的 探讨骨性Ⅲ类错（牙合）患者单、双颌手术方案的选择.方法 对满足纳入标准的38例患者进行治疗前后的X线头影测量分析,测量软组织、硬组织项目共28项.将采用单、双颌不同手术方式的两组患者治疗前、治疗后的各项目及其变化量分别进行对比分析.结果 单颌手术患者初诊SNA角、ANB角、U1/SN角、鼻唇角、G-SN-Pos角、Wits值及覆盖值更接近正常值.双颌手术更有利于上、下颌骨位置关系的改善、有利于下颌骨的逆时针旋转、上前牙去代偿更充分.结论 SNA角、U1/SN角、鼻唇角与正常值差距小于一个标准差的骨性Ⅲ类错（牙合）患者,可采用单纯下颌手术方式.超过此界限的患者应采用双颌手术方式.

Objective To explore how to make mandibular only or bimaxillary surgeries decisions for adult patients with Skeletal Class Ⅲ malocclusion.Methods The author selected 38 skeletal Class Ⅲ malocclusion patients.28 variables in the x-ray cephalometric lateral radiographs were selected to analyze the hard and soft tissues before and after the treatment and the change of the tissues.Results Mandibular-only surgery patients had better pretreatment SNA-angle,ANB-angle,G--SN-Pos angle,U1/SN angle,NLA,wits values and overjet than Bimaxillary surgery patients.Bimaxillary surgery is more conducive to gain better posttreatment skeletal relationship,more complete upper incisor decompensation and more mandibular counterclockwise rotation.Conclusions Patients with pretreatment SNA-angle,U1/SN angle and NLA that are within one standard deviation are suggested to accept mandibular surgery only.Patients who do not meet this requirement,otherwise,should accept two jaw surgery.