Characteristics of maxillofacial morphology of Angle Class II patients with temporomandibular disorders involving crepitus

Abstract Purpose To clarify the characteristics of maxillofacial morphology of Angle Class II orthodontic patients with temporomandibular disorders (TMD) involving crepitus suggesting osseous changes in the condyle, compared to Class II patients without TMD. Materials and methods Twenty-four Japanese females accompanied by Angle Class II malocclusion with crepitus and 24 females accompanied by Class II malocclusion without TMD were examined. Pretreatment panoramic radiographs were used to measure condylar ratio (condylar height/ramus height). Pretreatment lateral cephalograms were used to analyze skeletal and dental morphology. Angular and linear measurements were compared between groups. Multiple linear regression analysis was used to identify associations of overjet with other cephalometric measurement values in both groups. Results Class II patients with crepitus showed significantly smaller condylar ratio as compared to Class II patients without TMD. Class II patients with crepitus exhibited significantly greater clockwise rotation of the mandible, shorter ramus height, more retruded mandible, less labially inclined upper incisors, and smaller overjet. Overjet of Class II patients with crepitus was significantly associated with inclination of upper incisors and ramus height, whereas that of patients without TMD was significantly associated with inclination of both upper and lower incisors and sagittal intermaxillary relationship. Conclusion Significant smaller condylar ratio of Class II patients with crepitus suggested osseous changes in the condyle. Significant differences existed between morphological maxillofacial characteristics of Class II patients with and without crepitus. Overjet in Class II patients with crepitus correlated significantly with ramus height, attributed to resorbed deterioration and dysfunctional remodeling of the condyle.