Surgical approaches for condylar fractures related to facial nerve injury: deep versus superficial dissection

The aim of this study was to investigate the probability of facial nerve injury (FNI) in the treatment of condylar neck and subcondylar fractures (CN/SCFs) with percutaneous approaches and to identify factors predicting FNI. The data of 80 patients with 87 CN/SCFs were evaluated retrospectively. The primary outcome was FNI occurrence. The predictor variables were age, sex, aetiology, alcohol consumption, fracture site and pattern (dislocation or not), concomitant fractures, time interval to surgery, surgeon experience, plate type, and the dual classification of percutaneous approaches. The approaches were classified based on whether subcutaneous dissection traversed the marginal mandibular branch (MMB) deeply (deep group: submandibular and retroparotid approaches) or superficially (superficial group: transparotid, transmasseteric anteroparotid (TMAP), and high cervical-TMAP approaches). Twenty-two patients (27.5%) suffered FNI, of whom two in the deep group had permanent paralysis of the MMB. In the multivariate logistic regression model, deeply traversing surgery approaches (odds ratio 12.4, P = 0.025) and the presence of a dislocated fracture (odds ratio 6.66, P = 0.012) were associated with an increased risk of FNI. These results suggest that percutaneous approaches in the superficial group should be recommended for the treatment of CN/SCFs to reduce the risk of FNI.