Assessment of temporomandibular joint morphology of bifid mandibular condyles: a cone beam computed tomography study.

Background: Bifid mandibular condyle (BMC) is an extremely rare condition characterised by duplication of the head of the mandibular condyle. Knowledge about the morphology of BMC could help clinicians to understand the development course of condyle and differential diagnosis of fractures or tumours in the condylar area. The aim of this study was to examine temporomandibular joint (TMJ) hard tissue morphology of BMCs.

Materials and methods: 1,900 cone beam computed tomography (CBCT) scans of mandibular condylar heads were examined for the presence of bifidity. When BMCs were identified, morphological assessment and measurements of bone components of TMJs were done.

Results: 69 BMCs were detected in 56 patients (3%). It was observed that 43 (76.8%) patients presented unilateral, and 13 (23.2%) patients presented bilateral, BMCs. 59.4% of condyles were mostly seen in mediolateral (ML) orientation and 40.6% of them were both ML and anteroposterior (AP) orientation. 46.4% of cases showed a wide and shallow groove; 53.6% had a deep and narrow groove on coronal images. 60 BMCs had osteoarthritic changes.

Conclusions: CBCT is an excellent modality for accurate imaging of the bony components of the TMJ. Due to the widespread use of CBCT, the prevalence of BMC is likely to be higher than previously believed, and new cases reported in the literature could be useful for dentists for improving their understanding of this variation.