Facial nerve injuries associated with the retromandibular transparotid approach for reduction and fixation of mandibular condyle fractures

Abstract Purpose To document facial nerve (FN) injuries after surgical treatment of mandibular condylar fractures using the retromandibular transparotid approach and to identify risk factors associated with these injuries. Materials and methods A retrospective study of patients surgically treated for mandibular condylar fractures using the retromandibular transparotid approach over seven years was conducted. The primary study variable was the postoperative change in FN function after fracture fixation. Risk factors were categorized as demographic, anatomic, experience of the operator, fracture displacement/dislocation and number of miniplates placed at the fracture site. Appropriate statistics were computed. Results Ninety patients with 102 fractures were analysed. Thirty two fractures (31%) were located in the condylar neck and 70 fractures (69%) were subcondylar (located below the sigmoid notch). The condylar segment was undisplaced in twelve cases (12%), displaced medially in thirty five (34%), laterally displaced in thirty (29%) and dislocated in 25 (24.5%). In 18 fractures (18%), postoperative examination revealed various degrees of damage to the FN. All nerve injuries recovered completely in 8–24 weeks. In a multivariate model, condylar neck fractures, fracture dislocation and operator inexperience were associated with a statistically significant risk of postoperative deterioration of FN function ( P ≤ 0.05). Conclusion The majority of facial nerve injuries after surgical treatment of condylar fractures by the retromandibular transparotid approach are transient in nature. Condylar neck fractures, fracture dislocation and operator inexperience were associated with an increased risk for FN injury.