Postoperative Anatomic Position of Mandibular Free Flap Neocondyles Affects Patient Symptoms.

Importance: Mandibular condyle reconstruction with vascularized free flaps can re-establish form and function after resection. However, no reports have been published regarding the postoperative anatomic seating of these reconstructions. Objective: To use postoperative axial imaging to determine whether condylar reconstructions migrate and correlate their ultimate location with postoperative symptoms. Design, Setting, and Participants: A prospectively maintained database of free flap cases performed between 2006 and 2019 at a single institution was queried. Twenty-one consecutive patients who underwent reconstructions that involved the mandibular condyle who also had postoperative axial imaging were selected for review. Distances were measured from the reconstructed condyle to the lateral, superior, and posterior aspect of the temporomandibular joint (TMJ), and correlated with postoperative symptoms and jaw function. Main Outcomes and Measures: Condyle displacement, postoperative diet, jaw pain, trismus, and malocclusion. Results: In total, 57% of patients had 1 cm or greater displacement of the condylar reconstruction from the TMJ in at least one vector. Anterior displacement of condyle by >1 cm was associated with jaw misalignment (42.8%) and clicking (14.3%) [odds ratio (OR) 37.3, 95% confidence interval (CI) 1.6-866.9, p = 0.024]. However, 83.3% of these patients were able to return to a normal diet and denied dysphagia. All edentulous patients had acceptable anteroposterior alignment, but 42.8% of dentulous patients had anterior displacement >1 cm (p = 0.12). Inferior displacement >1 cm was associated with dysphagia (OR 23, 95% CI 1.07-494.6, p = 0.04), but not pain or trismus. Eleven patients had multiple postoperative computed tomography scans, on average 21 months apart. The reconstructed location was stable in all 11 patients. Conclusions and Relevance: Patients undergoing free flap reconstruction of the mandibular condyle often return to normal diet, even when their reconstructions do not sit perfectly within the TMJ. Anterior displacement of the neocondyle may be more common in dentulous patients due to stress on the joint from chewing and produces some dysfunction and misalignment. Inferior displacement of the neocondyle may result in dysphagia. The reconstructed condyles are unlikely to migrate over time.