The condyle is the most common site of mandibular fracture. In the present study, an attempt was made to utilize three-dimensional computed tomography (3D-CT) images to evaluate mandibular condyle fractures and identify prognostic indicators of malocclusion after closed treatment. Accurate morphometric measurements were performed using 3D-CT images obtained before trauma, after trauma, and after healing. Morphometry revealed significant differences in loss of ramus height (LRH) and lateral movement length in patients with malocclusion, and significant LRH differences in patients with other maxillomandibular fractures after healing, or in those with dislocation-displacement. The present method of 3D-CT image analysis appears useful for evaluation of condylar fractures.

Although closed reduction is common for condylar fractures, bone fragments may heal improperly. This study aimed to investigate the healing morphology of unilateral condylar fractures. We retrospectively investigated 70 patients with unilateral condylar fractures. Clinico-statistical analyses were performed on the whole-condylar fracture, closed reduction, and observation/functional therapy groups. Among these patients, 52 patients aged older than 16 years underwent closed reduction. The extent of maximum mouth opening, the incidence of malocclusion, and the relationship between healing morphology and Arbeitsgemeinschaft für Osteosynthesefragen classification or trismus were analyzed in the closed reduction group. There were significant differences in age (P = 0.008) and sex (P = 0.025) between the closed reduction and observation/functional therapy groups. However, there were no significant differences in trauma etiologies and concomitant fractures between the 2 groups. The average maximum mouth opening extent for unilateral fractures after closed reduction was 42.6 ± 6.1 mm. Only 1 case (2.1%) of post-treatment malocclusion was observed. In all the MacLennan classification of deviation or more, regardless of the classification, upper fractures (head and upper neck) tended to heal through a spherical (P < 0.001) morphology, whereas lower fractures (lower neck and subcondylar) tended to heal through an L-shaped and lateral fusion (P < 0.001). There was no significant difference in the incidence of trismus between the healing morphology of unchanged type and others (P = 0.690). Our results elucidated the etiology, dysfunction, and healing morphology classification of unilateral mandibular condyle fractures treated with closed reduction.