Clinical, retrospective case-control study on the mechanics of obstacle in mouth opening and malocclusion in patients with maxillofacial fractures.

This study aims to identify and distinguish various factors that may influence the clinical symptoms (limited mouth opening and malocclusion) in patients with maxillofacial fractures. From January 2000 to December 2009, 963 patients with maxillofacial fractures were enrolled in this statistical study to aid in evaluating the association between various risk factors and clinical symptoms. Patients with fractured posterior mandibles tended to experience serious limitation in mouth opening. Patients who sustained coronoid fractures have the highest risk of serious limitation in mouth opening (OR = 9.849), followed by arch fractures, maxilla fractures, condylar fractures, zygomatic complex fractures and symphysis fractures. Meanwhile, the combined fracture of zygomatic arch and condylar process results in normal or mild mouth opening. High risks of sustaining malocclusion are preceded by the fracture of nasal bone (OR = 3.067), mandible, condylar neck/base, combined fracture of zygomatic arch and condylar process, mandibular body, bilateral condylar, dental trauma, mandibular ramus, symphysis, mandibular angle and mid-facial. Patients who experienced serious limitation in mouth opening are treated with surgery more frequently (OR = 2.118). No relationship exists between the treatment options and the patients with malocclusion.