# Bifid mandibular condyle: investigating the association with temporomandibular joint disorders on three-dimensional T2-weighted SPACE sequences performed for brain magnetic resonance radiological scanning techniques

## TL;DR

This study investigates if a rare jaw bone variation called bifid mandibular condyle is linked to temporomandibular joint disorders using brain MRI scans.

## Contribution

The study is the first to use 3D T2-weighted SPACE MRI sequences for brain scans to evaluate TMJ abnormalities in patients with BMC.

## Key findings

- 82.8% of patients with BMC showed at least one TMJ-related abnormality on MRI.
- Disc degeneration was the most common TMJ abnormality observed in BMC patients.
- BMC was found bilaterally in 41.4% of patients, and more common in females than males.

## Abstract

Background: Bifid mandibular condyle (BMC) is a rare anatomical
variation whose cause has not been fully understood. It has been hypothesized
that BMC may be associated with an increased frequency of temporomandibular joint
(TMJ) abnormalities. The aim of the study was to comparatively review the
magnetic resonance imaging (MRI) archives of the hospital focusing on patients
with BMC who underwent brain MRI using the T2-weighted 3D sampling perfection
with application-optimised contrast using different flip angle evolutions (SPACE)
radiological scanning techniques. Methods: The TMJ was
thoroughly evaluated in patients diagnosed with BMC. Pathological findings were
categorized into six classes: disc degeneration, disc displacement, disc
deformation, degenerative osteoarthritis, effusion, and subluxation.
Results: A total of 29 patients with BMC were identified,
including 9 males (31%) and 20 females (69%). BMC was located on the right side
in 10 patients (34.5%), on the left side in 7 patients (24.1%), and bilaterally
in 12 patients (41.4%). Only 5 patients (17.2%) showed no pathological findings
on MRI, while 24 patients (82.8%) exhibited at least one TMJ-related
abnormality. Among these, 22 patients (75.9%) had disc degeneration, 8 (27.6%)
had disc displacement, 10 (34.5%) had disc deformation, 2 (6.9%) had
degenerative osteoarthritis, 12 (41.4%) had effusion, and 5 (17.2%) had
subluxation. Conclusions: TMJ disc pathology is the most frequently
observed abnormality in BMC, although it remains uncertain whether this
relationship is causal or coincidental. BMC may contribute to the development of
TMJ disorders; however, further research with larger sample sizes is needed to
clarify its role.