青少年牙发育不全患者颅面结构的初步研究

目的探讨牙发育不全患者的颅面结构,为临床诊治提供参考。方法选择英国牙发育不全患者病历59份纳入研究组,根据缺牙类型和缺牙数将研究组分为轻度、中度、重度、极重度共4个亚组,其中男27例,女32例,平均年龄（13.1±3.1）岁。以Woodworth等报道的正常资料为对照组。对所有研究对象进行X线头影测量对比分析。结果研究组与对照组的SNA、SNB、MMA差异无统计学意义,且均在正常值范围内。同T3组相比,T4组的SNB增大（t=-2.76,P=0.015）、MMA减小（t=-3.03,P=0.007）、ANB减小（t=-2.26,P=0.034）,三者差异均有统计学意义;59例牙发育不全患者中Ⅲ类颅面结构患者居多。结论牙发育不全患者的平均头影测量值在正常值范围内,59例牙发育不全患者中Ⅲ类颅面结构患者居多、上下颌平面角减小。

A Study of the Skeletal Relationships with Young Hypodontia Patients

Objective To study the eraniofacial features of hypondontia patients, so as to provide the theoretical facts for diagnosis and treatment. Methods 59 hypodontia patients were divided into four groups based on the number of missing tooth types （mild group, moderate group, severe group, extremely severe group） 27 males, 32 females, mean age （ 13.1±3.1 ） years. The control group comprised 75 age-matched children without orthodontic treatment. The cepha- lograms were analyzed by using computer for all subjects. Results The mean SNA, SNB, MMA angles were within normal limits, but there was a statistically significant reduction in the MMA when more than one tooth type missed （ P = 0. 007 ） and ANB angle decreased as the nmnber of missing tooth types increased （ P = 0. 034 ）. Conclusion The mean values for the whole sample were within the normal range and did not demonstrate any feature specific to the group. But patients with more severe hypodontia showed tendencies to a Class Ⅲ skeletal relationship and a reduced maxillary-mandibular planes angle.