前牵引矫治乳牙期严重骨性Ⅲ类错畸形的侧貌变化

Dentoskeletal and soft tissue profile changes after maxillary protraction with rapid expansion for the patients with primary class Ⅲ

目的探讨上腭快速扩大联合前牵引矫治乳牙期严重骨性Ⅲ类错畸形和矫治前后颌骨软组织侧貌头影测量值的变化。方法选择乳牙期严重骨性Ⅲ类错畸形患儿8名,患儿呈凹面型,前牙或合并后牙反,上颌相对下颌后缩,乳磨牙末端呈近中阶梯,不存在功能性下颌移位。上下牙列无牙周疾病,牙体疾病须治疗,之前未做过正畸治疗。应用上腭快速扩大联合前牵引矫治,正畸前后头影测量,采用配对t检验,统计学分析结果。结果乳牙期严重骨性Ⅲ类错畸形患儿经上腭快速扩大联合前牵引矫治6个月左右,患儿的上颌N-A增长,上颌前移,N-B缩短,下颌后旋,颌骨面角减小、软组织面角相应减小;骨组织和软组织前下面高增加,乳上切牙唇倾,乳下切牙舌倾;上唇突度增大、倾斜度减小,下唇突度减小、倾斜度减小。结论上腭快速扩大联合前牵引矫治乳牙期严重骨性Ⅲ类错畸形,凹面型显著改善且呈直面型。颌骨和软组织侧貌发生相应的改变。

Objective To evaluate the changes of dentoskeletal and soft tissue profile of the patients with skeletal class Ⅲ after maxillary protraction with rapid expansion in the primary class Ⅲ dentition. Methods Eight patients with serious skeletal class Ⅲ, 5 males and 3 females, in the primary dentition were selected. The patients present with a concave facial profile, anterior or posterior crossbite. No apparent mandibular displacement was found in all patients. Cephalograms were taken before and after maxillary protraction with expansion. Results The maxillary was protracted significantly, whereas the mandible was positioned backward significantly, with a concomitant decrease in the skeletal facial angle. The corresponding soft tissue changes displayed significant decrease in soft tissue facial angle, the skeletal and soft tissue profile showed similar increases in lower facial height. The maxillary incisors tipped labially, while the mandibular incisors tipped lingually. Lip structure changed with increased upper lip convesity and decreased lower lip convexity, the inclination of the upper and the lower lip decrease significantly. Conclusion This treatment shows that significant dentoskeletal and soft tissue changes and improvements in dentofacial profile result from 6 months of treatment with maxillary expansion and protraction.