Lateral Pterygoid Fracture Can Predict a Mandible Fracture

Abstract

Objective: Isolated lateral pterygoid plate fractures on head CT imaging can serendipitously be associated with mandible fractures on subsequent maxillofacial imaging. Our objective is to understand the mechanism and to establish a protocol for the radiographic evaluation for this phenomenon. Method: We performed a retrospective case series of 7 maxillofacial trauma patients with evidence of isolated lateral pterygoid fractures noted on CT images between 2006 and 2012 at our tertiary care institution. Subsequent maxillofacial CT images with coronal, axial, and sagittal views allowed for complete evaluation of maxillofacial trauma. Results: Seven patients between 2006 and 2012 who sustained facial trauma were found to have isolated lateral pterygoid plate fractures. Subsequent evaluation via maxillofacial CT showed associated mandible fractures. All the patients were men with an average age of 37 years. Seven patients had an ipsilateral subcondylar fracture, 2 had a symphyseal fracture, 2 had a body fracture, and 1 had a coronoid fracture. Conclusion: Isolated lateral pterygoid fractures noted on head CTs are suggestive of associated mandibular fractures. The proposed mechanism is an acute force on the mandible that is traduced through the pterygoid muscles. A dedicated maxillofacial CT may reveal an associated mandibular fracture even in the setting of negative clinical exams.