Three-dimensional mandibular motion after closed and open reduction of unilateral mandibular condylar process fractures

Objective: To detect the changes in 3D mandibular motion after two types of condylar fracture therapies. Materials and methods: Using a 3D motion analyzer, free mandibular border movements were recorded in 21 patients successfully treated for unilateral fractures of the mandibular condylar process (nine patients: open reduction, rigid internal fixation, and functional treatment; 12 patients: closed reduction and functional treatment; follow-up: 6-66 months), and in 25 control subjects. Results: No differences were found among the groups at maximum mouth opening (MO), protrusion and in lateral excursions. During opening, the patients had a larger maximal deviation to the fractured side than the controls (controls 2.3 mm, open treatment 3.9 mm, closed treatment 4.2 mm; Kruskal-Wallis test, p = 0.014; closed treatment vs. controls, p = 0.004), with a larger coronal plane angle (controls 2.4°, open treatment 3.6°, closed treatment 4.4°; p = 0.016; closed treatment vs. controls, p = 0.013). In the closed treatment patients, a longer follow-up was related to increased maximum MO (p = 0.04), sagittal plane angle (p = 0.03), and reduced lateral mandibular deviation during MO (p = 0.03). Conclusion: Mandibular condylar fractures can recover good function; some kinematic variables of mandibular motion were more similar to the norm in the open treatment patients than in closed treatment patients.