数字化导板在颞下颌关节强直保留髁突手术中的指导作用

目的 设计制作数字化导板（digital guide）,用于指导颞下颌关节强直（temporomandibular joint ankylosis,TMJA）外侧成形术（lateral gap arthroplasty,LAP）中髁突残余（residual condyle）的保留,并评价其应用效果。方法 收集2012年1月—2014年1月间收治的TMJA患者,选择骨球内侧存在髁突残余者纳入研究。采用 ProPlan CMF 1.4软件进行术前设计,明确骨球范围及其与髁突残余的关系,设计数字化导板并采用快速成型技术制作完成,术中用以指导骨球的截除。评价导板的就位情况及对重要解剖结构的保护。术后拍摄CT评价截骨效果并与手术设计进行拟合,评价导板的准确性。结果 5例7侧关节手术中,导板就位稳定,指导截骨准确,未伤及颅底和外耳道前壁,有效保护了内侧的髁突残余。术后CT显示截骨与术前设计的平均误差为1.044 mm。结论 数字化导板可以准确有效地指导强直骨球的切除,有效保护了髁突残余、颅底和外耳道。

Digital guide assisted in retaining the residual condyle of temporomandibular joint ankylosis surgery

PURPOSE: We design and fabricate a digital guide to help retaining the residual condyle in the lateral gap arthroplasty (LAP) of temporomandibular joint ankylosis (TMJA) and evaluate the effect. METHODS: All TMJA patients treated in our department from January 2012 to January 2014 were included for the study with the inclusion criteria as follows there was a residual condyle on the coronal CT and digital guides were designed to help retaining the residual condyle in LAP; ProPlan CMF 1.4 software (Materialise Medical, Leuven, Belgium) was used to complete preoperative design. Range and relation between bone fusion and residual condyle was determined. The guides were designed and made by stereolithography, and then applied in surgeries. The effect of the digital guides including the intraoperative fitness and protection of important structures was evaluated. The fusion results of the postoperative CT and preoperative design were analyzed. RESULTS: Among the total 5 surgeries with 7 joints, the digital guides fit well and accurately guide the osteotomy. The residual condyle, skull base and external auditory canal were well protected. Postoperative CT showed the average difference between the surgical results and the preoperational designs was 1.044 mm. CONCLUSIONS: Digital guides can accurately guide the osteotomy of the lateral bone fusion and protect residual condyle, skull base and external auditory canal.