Repairing Facial Fractures with Interrupted Maxillary-mandibular Arches by Computer-assisted Reverse Planning Model Surgery.

BACKGROUND: Management of comminuted facial fractures with maxillary-mandibular arch interruption is difficult, resulting in inadequate bone reduction and malocclusion. Traditionally, a good quality dental splint is helpful, but difficult to obtain in acute trauma. We apply a computer-assisted design and three-dimensional printing technology to improve splint fabrication and utilization, thus facilitating restoration of dental occlusion and facial fracture. METHODS: We retrospectively reviewed patients who suffered from facial fractures with interruption of the maxillary-mandibular arches. We developed the "computer-assisted reverse planning and three-dimensional printing model surgery" algorithm and applied it in selected patients. An occlusal splint was created as a surgical guide to enhance the maxilla-mandibular unit repair by taking care of the bone reduction and occlusion. All included patients were followed up to assess the functional outcome and patients suitable for this method. RESULTS: From Jan 2015 to Aug 2020, 10 patients (eight men and two women) with comminuted facial fractures were included. The average time of surgery was 9.2 days. The average follow-up time was 8.6 months. There was no patient who needed major revision to correct malocclusion or facial asymmetry. CONCLUSIONS: A computer-assisted design splint decreases intraoperative inaccuracies and difficulty in comminuted maxillo-mandibular fractures. It is a useful and reliable alternative. Collaboration with an experienced engineer and patient selection are indispensable in delivering successful outcomes. Patients who have more than three bone fragments in a single dental arch or more than four bone fragments in the entire maxillary-mandibular unit appear to be excellent candidates for this method.