Objective: To preliminarily verify the effectiveness of self-designed artificial condyle-mandibular distraction (AC-MD) complex in the treatment of Pruzansky type ⅡB and Ⅲ hemifacial microsomia (HFM) through model test.
Methods: Five children with Pruzansky type ⅡB and Ⅲ HFM who were treated with mandibular distraction osteogenesis (MDO) between December 2016 and December 2021 were selected as the subjects. There were 3 boys and 2 girls wih an average age of 8.4 years (range, 6-10 years). Virtual surgery and model test of AC-MD complex were performed according to preoperative skull CT of children. The model was obtained by three-dimensional (3D) printing according to the children's CT data at a ratio of 1∶1. The occlusal guide plate was designed and 3D printed according to the children's toothpaste model. The results of the model test and the virtual surgery were matched in three dimensions to calculate the error of the residual condyle on the affected side, and the model test was matched with the actual skull CT after MDO to measure and compare the inclination rotation of the mandible, the distance between the condylar of the healthy side and the residual condyle of the affected side, and the lengthening length of the mandible.
Results: The error of residual condyle was (1.07±0.78) mm. The inclination rotation of the mandible, the distance between the condylar of the healthy side and the residual condyle of the affected side, and the lengthening length of the mandible after 3D printing model test were significantly larger than those after MDO ( P<0.05).
Conclusion: In the model test, the implantation of AC-MD complex can immediately rotate the mandible to the horizontal position and improve facial symmetry, and the residual condyle segment can be guided close to the articular fossa or the preset pseudoarticular position of the skull base after operation.
目的: 通过模型试验初步验证自行设计的人工髁突-下颌骨延长器（artificial condyle-mandibular distractor，AC-MD）复合体在Pruzansky ⅡB、Ⅲ型半侧颜面短小症（hemifacial microsomia，HFM）治疗中的有效性。.
方法: 选取2016年12月—2021年12月采用下颌骨牵引成骨术（mandibular distraction osteogenesis，MDO）治疗的5例Pruzansky ⅡB、Ⅲ型HFM患儿作为研究对象。其中男3例，女2例；年龄6～10岁，平均8.4岁。根据患儿术前头颅CT行AC-MD复合体虚拟手术和模型试验，模型依据患儿CT数据按1∶1经3D打印所得，结合患儿口腔石膏模型设计并3D打印模型试验所需的咬合导板。将模型试验与虚拟手术结果行三维配比，测算患侧残突整体误差；将模型试验与患儿实际MDO术后头颅CT行三维配比，测量并比较下颌骨倾斜度转动、健侧髁突-患侧残突距离及下颌骨延长长度。.
结果: 残突整体误差为（1.07±0.78）mm。3D打印模型手术后下颌骨倾斜度转动、健侧髁突-患侧残突距离及下颌骨延长长度均显著大于患儿实际MDO术后各相应指标，差异有统计学意义（ P<0.05）。.
结论: 在模型试验中，AC-MD复合体植入可即刻旋转下颌骨至水平位、改善面部对称性；术后可导引残突骨段接近关节窝或颅底预设假关节位。.
Keywords: Hemifacial microsomia; mandibular distraction; model test.