锥形束CT在观察幼儿期上颌乳、恒中切牙生长发育变化中的应用

Development of primary and permanent maxillary central incisors inpreschool children observed with dental cone beam CT

摘要:

目的 观察幼儿期儿童上颌乳、恒中切牙生长发育的动态变化。方法 拍摄46个1~6岁幼儿干颅标本上颌前牙区的锥形束CT影像,观察上颌乳、恒中切牙在矢状面上的生长发育变化,并对上颌乳、恒中切牙的牙冠宽度,牙体长度以及恒中切牙的切端硬组织厚度进行测量分析。结果 获得了1~6岁组上颌乳、恒中切牙锥形束CT矢状面典型图像。各组间上颌乳中切牙牙冠宽度差异无统计学意义(P>0.05),2岁组、6岁组牙体长度＜其他各组(P<0.001)。2岁组上颌恒中切牙牙冠宽度＜其他各组(P<0.001),牙体长度从1岁组到6岁组随年龄增加逐渐增大(P<0.001)。切端硬组织厚度从1岁组到4岁组随年龄增加逐步增大(P<0.001),4、5、6岁组间差异无统计学意义(P>0.05)。结论 锥形束CT矢状面典型图像形象地显示了上颌乳、恒中切牙生长发育的动态变化,相关测量数据对儿童口腔临床治疗有重要参考意义。

Abstract:

Objective To observe the development changes of primary and permanent maxillary central incisors in preschool children. Methods The dental cone beam CT (CBCT) images of 46 skulls of children aged 1-6 years were taken. The development changes of primary and permanent maxillary central incisors were observed and the width of tooth crown, the length of tooth, and the hard tissue thickness of permanent maxillary central incisors were measured. Results The typical sagittal images of dental CBCT images were obtained. And there was no difference on the width of tooth crown among different age groups (P>0.05), while the length of primary maxillary central incisors in 2 year and 6 year age groups were smaller than those in other age groups (P<0.001). In permanent maxillary central incisors, the width of tooth crown in 2 year age group was smaller than that in other age groups (P<0.001)；the length of tooth was increased from 1 to 6 years with the age (P＜0.001)；the hard tissue thickness was increased from 1 to 4 years with the age (P<0.001); while there was no difference among 4-y, 5-y and 6-y age groups (P>0.05). Conclusion The development changes of primary and permanent maxillary central incisors are graphically illustrated in dental CBCT images, which are of value for clinical treatment of pediatric dentistry.