Three-dimensional modeling of the scapular tip for anterolateral and lateral mandibular defects

Three-dimensional (3D) computational modeling represents an invaluable surgical tool for complex reconstructive cases. There exists limited data on 3D imaging to evaluate the use of the scapular tip free flap in complex, anterolateral mandibular reconstructions. The purpose of this study is to radiographically assess the scapular tip free flap in anterolateral defects of the mandible.

A retrospective case series of 50 patients was performed on head and neck cancer patients treated at Michigan Medicine from 2013 to 2018. Patients who had pre-operative computed tomography neck and thorax for review were included.

The scapular tip was able to cover defects from the ipsilateral mandibular angle to the symphysis in all cases. On average, the bone extended to cover defects from the mandibular angle to 17 mm (SD ± 3.6 mm) beyond the mandibular symphysis, which equates to 70% (95% CI 0.66-0.74) of the distance from the symphysis to the contralateral mental foramen.

Use of the scapular tip as a donor site for reconstruction of the mandibular body can be evaluated pre-operatively utilizing 3D imaging. All patients were able to achieve posterior coverage to the vertical plane of the mandibular condyle and contralateral extension across the symphysis on average extends almost three-fourths of the distance to the mandibular foramen. The extent of contralateral coverage can be more accurately delineated utilizing the patient's pre-operative imaging.