基于锥形束CT分析骨性Ⅰ类错[牙合]成年女性牙列拥挤度与牙量和基骨形态的关系

Correlation of the dental crowding with the tooth size and the basal bone form of adult women with skeletal classⅠmalocclusion based on cone-beam CT

目的:应用锥形束CT(CBCT)测量分析骨性Ⅰ类错牙合成年女性的牙列拥挤度与牙量及基骨形态的关系。方法:选取骨性Ⅰ类成年女性患者60例,根据上下颌牙列拥挤程度分为非拥挤组(n=30)和拥挤组(n=30)。利用石膏模型测量每位患者的上下颌牙量(MxTS和MdTS);利用CBCT扫描并使用三维重建后的图像对上下颌基骨长度(MxBL、MdBL)及宽度(MxBW1、MxBW2和MdBW1、MdBW2)相关指标进行定点测量。比较两组各指标差异,分析拥挤度与牙量及基骨形态的相关性。结果:拥挤组的MxBL、MdBL、上颌根尖水平的MxBW1、上颌根分叉水平的MxBW2、下颌根分叉水平的MdBW2均小于非拥挤组(P<0.05)。上颌牙列拥挤度与MxBL、MxBW1和MxBW2呈负相关(r=-0.453、-0.359、-0.395,P<0.05);下颌牙列拥挤度与MdBL和MdBW2呈负相关(r=-0.507、-0.367,P<0.05)。结论:基骨形态大小与牙列拥挤度有较强的相关性,对于某些牙列拥挤的患者可优先考虑非拔牙矫治如扩弓。

Aim:To investigate the correlation of the dental crowding with the tooth size and the basal bone form of adult women with skeletal classⅠmalocclusion based on cone-beam CT.Methods:A total of 60 adult female patients with skeletal classⅠmalocclusion were selected and allocated into non-crowded group(n=30)and crowded group(n=30)according to the degree of dental crowding.Initial dental casts were conducted to measure the tooth size of the maxilla and mandible for each patient(MxTS and MdTS).Cone-beam CT was utilized and the images after three-dimensional reconstruction were used to measure the basal bone length(MxBL and MdBL)and width(MxBW1,MxBW2 and MdBW1,MdBW2)of the maxilla and mandible of the patients.The indicators measured above between the 2 groups were compared,and the correlations of the dental crowding with the tooth size and the basal bone form were analyzed.Results:MxBL,MdBL,MxBW1 at the level of maxillary root apex,MxBW2 at the level of maxillary root bifurcation,and MdBW2 at the level of mandibular root bifurcation in crowded group were significantly smaller than non-crowded group(P<0.05).The crowding of maxillary was negatively correlated with MxBL,MxBW1 and MxBW2(r=-0.453,-0.359,-0.395,P<0.05);the crowding of mandibular was negatively correlated with MdBL and MdBW2(r=-0.507,-0.367,P<0.05).Conclusion:The correlation between the basal bone form and the dental crowding is relatively strong,suggesting that non-extraction treatments such as arch expansion should be given priority for patients with dental crowding.