Correlation Between Craniofacial and Condylar Path Asymmetry

Purpose: The purpose of this study was to examine the correlation between the condylar path length and craniofacial morphology in patients with mandibular prognathism and deviation, and investigate changes in the condylar path length and temporomandibular joint disorders after intraoral vertical ramus osteotomy (IVRO). Patients and Methods: Sixteen Japanese patients exhibiting mandibular prognathism and deviation were studied. For their correction, all patients underwent IVRO. In the case of patients with severe occlusal cant after cant correction by Le Fort I osteotomy, IVRO was carried out on the same day. The change in craniofacial morphology was assessed with frontal cephalograms and submentovertex radiograms. Condylar path changes were assessed using a 6° of freedom measuring device. All patients were examined with regard to their temporomandibular joint (TMJ) function. Results: Before treatment, mandibular deviation was moderately related to the asymmetries of craniofacial morphology and condylar path length. The rate of incidence of TMJ sounds on the deviated side was significantly higher than that on the nondeviated side. After treatment, although the condylar path length as well as condylar position had changed to become bilaterally symmetric, there was still a significant difference during protrusive excursion and maximal open-close movements. TMJ sounds disappeared in 64.3% of patients. Conclusion: Mandibular deviation was found to be strongly related to the morphologic and functional asymmetries in patients with mandibular prognathism and deviation. The condylar path length and condylar position were improved after the correction of mandibular deviation with IVRO.