18例12～20岁严重骨性Ⅲ类牙颌畸形非手术正畸治疗的初步研究

目的　旨在对非手术矫治成功的 12～ 2 0岁严重骨性Ⅲ类牙颌畸形病例矫治前后的X线侧位片作头影测量分析 ,进行牙及软组织侧貌的评价 ,为临床矫治提供有价值的依据。方法　 18例恒牙期与成人严重骨性Ⅲ类牙颌畸形病例 ,男 5例 ,女 13例。年龄 12～ 2 0 (14 6± 2 5 )岁。 12例采用Tip Edge差动直丝弓矫正技术 ,6例采用Begg细丝弓矫正技术。平均治疗时间为 (2 5±0 8)年。病例选择标准 :①近中或超完全近中磨牙关系 ,后者指上颌第一恒磨牙近中颊尖咬合于下颌第二恒磨牙颊沟 ;②下颌不能后退 ;③Ⅲ类骨型 (ANB <- 1 5°) ;④多为高角病例 ,SN MP平均值为(34 9± 5 9)°,有 4例合并前牙开畸形 ;⑤侧貌呈凹面型 ;⑥已经其他正畸医师诊断为手术适应证 ,但患者及家属拒绝接受手术治疗。治疗前后拍摄头影测量片 ,用常规头影测量分析方法进行分析。计算头影测量各指标的均值与标准差 ,采用配对t检验分析治疗前后各指标的统计学差异。结果　治疗结束后上颌前牙发生明显的唇向倾斜移动 ,下颌前牙发生明显的舌向倾斜移动 ,建立正常覆覆盖关系。U1 SN角平均增加了 5 9° (P <0 .0 0 1) ,L1 MP角平均减少了 6 6°(P <0 0 0 1)。上下唇至Sn Pg审美线的差距 ,由矫治前的负均值变为矫治后的正均值且差异有

Preliminary study of non-surgical treatment of severe Class Ⅲ malocclusion in 18 patients of 12-20 years old

OBJECTIVE: To analyze effects of non-surgical treatment on subjects of 12-20 years old with severe skeletal Class III deformity and to directly evaluate dental and facial profile changes. METHODS: Eighteen patients with severe skeletal Class III malocclusion (male 5, female 13), diagnosed as indication for orthognathic surgery, were included in the study. The average age was 14.6 +/- 2.5 years old., with age range from 12 years old to 20 years old. 12 cases were treated with Tip-Edge straight-wire technique and 6 cases with Begg light wire technique. The average treatment time was 2.5 +/- 0.8 years. The selection criteria included: (1) mesial or superior mesial Class III molar relationship, with maxillary first molar occlude the buccal groove of the mandibular second molars (2) no mandibular shift (3) ANB < -1.5 degrees (4) high angle cases with average value of SN-MP 34.9 degrees +/- 5.9 degrees, 4 cases present with openbite (5) concave facial profile (6) originally classified as surgery cases. Lateral cephalometric films taken at the beginning and the end of the treatment were analyzed with traditional cephalometric analysis. The arithmetic mean (Mean) and standard deviation (SD) were calculated for each variable. Paired t-test was performed to evaluate the significant treatment change. RESULTS: Normal overjet and overbite were established with proclination of upper incisors and retroclination of lower incisors. Inclination of upper incisors was increased 5.9 degrees when measured with the angle of upper incisor to SN plane (P < 0.01). Inclination of lower incisors was decreased 6.6 degrees when measured with the angle of lower incisor to mandibular plane (P < 0.001). Negative value of the distance difference of upper lip and lower lip to Sn-Pg' at the beginning of treatment changed to positive value with significant difference (P < 0.001). CONCLUSION: Successful treatment effects could be obtained with non-surgical therapy in severe skeletal Class III malocclusion in permanent dentition. Remarkable soft-tissue change was noted after the treatment and concave facial profile changed to straight profile.