隐形矫治在口腔扫描图像上牙列中线的确定方法

Determination Method of Dental Midline on Oral Scanning Image in Invisible Treatment

目的:探究一种帮助医生在隐形矫治方案制定时,精准的确定牙列终末状态的中线位置的方法,以帮助解决目前正畸临床中牙列中线确定方法可重用性低、稳定性差、受正畸医师经验所限的问题,具有一定的辅助参考意义。方法:对于接受隐形矫治的12例错[[[牙合]]]畸形患者,将每个患者矫治前的CBCT图像与口腔扫描图像进行配准,在CBCT图像的三个视图上结合其颅骨的三维重建模型确定正中矢状参考平面,并将该平面映射至口腔扫描模型以确定牙列中线调整方案,计算本研究得到的牙列中线调整值,并与正畸专家医师初始设计的牙列中线调整值进行比较。结果:本研究得到的牙列中线调整值与正畸专家医师临床设计的牙列中线调整值相比,最大偏差0.46 mm,最小偏差0.05 mm(<0.5 mm),在统计学上无显著差异(P>0.05),一致性良好。结论:本研究提出的方法能够准确的在口腔扫描图像中确定牙列终末状态的中线位置,有助于年轻正畸医师在隐形矫治中确定牙列中线、排列牙齿。

Objective:To correct the dentition midline position of the terminal state on the patient's oral scanning image in invisible appliance,to solve the problems of poor stability,low efficiency,and limitation of orthodontist experience in determining dentition midline in orthodontic clinics,and to provide more accurate reference for the orthodontic treatment.Methods:12 malocclusion patients treated with invisible orthodontic treatment were selected according with the standard conditions.The CBCT images of each patient were matched with the oral scanning images before orthodontic treatment to determine the median sagittal reference plane by combining the three-dimensional digital reconstruction model of skull on the three views of the CBCT image.The plane was mapped to the oral scanning model to determine the midline adjustment,and the midline adjustment value of the dentition obtained from the study was compared with the midline adjustment of the dentition value initially designed by the expert orthodontists.Results:The maximum deviation of the adjusted value for the dentition midline obtained in this study was 0.46 mm and the minimum deviation was 0.05 mm compared with the adjusted value designed by the expert orthodontists(P>0.05).The consistency was good.Conclusions:The method can effectively determine the dentition midline position of the terminal state in the oral scanner image,and it helps the junior orthodontists to determine the dentition midline and arrange the teeth by using invisible appliance.