减数下颌第二磨牙矫治恒牙期严重骨性Ⅲ类错(牙合)畸形的探索

目的研究拔除结合固定矫正技术矫治恒牙期严重骨性Ⅲ类错(牙合)畸形的疗效。方法 14例恒牙期严重骨性Ⅲ类错(牙合)畸形患者,男性4例,女性10例。年龄12.0～17.1岁,平均(13.3±0.8)岁。全部患者均被视为手术适应证,但患者均拒绝接受手术治疗。故采用拔除结合固定矫治器进行非手术矫治。治疗前后头颅侧位片以常规头影方法及 Pancherz 头影测量方法进行分析。结果与矫治前相比,矫治后下颌中切牙角减少11.7°,差异有统计学意义(P<0.001)。上下唇凸点至 SnPg'距离的差值,由矫治前的负值转变为矫治后的正值,差异有统计学意义(P<0.001)。结论减数结合固定矫正技术可成功矫治恒牙期严重骨性Ⅲ类错(牙合)畸形,并使患者软组织侧貌发生显著改变。

Preliminary investigation of lower second molar extraction in correction of severe skeletal class Ⅲ malocclusion

OBJECTIVE: To evaluate dento-skeletal and soft-tissue profile changes after extraction of lower second molars and treatment using fixed appliances in severe class III subjects. METHODS: Fourteen patients with severe skeletal class III malocclusion (male 4, female 10, age rang 12.0 - 17.1 years old, mean age 13.3 +/- 0.8), diagnosed as requiring orthognathic surgery, but rejected surgical therapy were included in the study. Lateral cephalometric films taken at the beginning and end of treatment were analyzed using Pancherz analysis and a traditional cephalometric analysis. RESULTS: After active treatment, inclination of lower incisors was decreased 11.7 degrees when measured to the mandibular plane (P < 0.001). A negative value of the distance between upper and lower lip position to SnPg' at the beginning of treatment changed to a positive value (P < 0.001). CONCLUSIONS: The results of the current preliminary study suggest that success in the treatment of some severe class III deformity in the permanent dentition can be achieved with fixed appliances and extraction of lower second molars. A remarkable soft-tissue change was noted after the treatment and concave facial profiles changed to straight profiles.