Role of Magnetic Resonance Imaging in Temporomandibular Joint Ankylosis - An Evaluative Study

Temporomandibular joint (TMJ) ankylosis is a pathologic condition where the mandible is fused to the fossa by bony or fibrotic tissues. Haemorrhage is one of the major complications during TMJ surgery especially in ankyloses due to altered anatomy. The aim of the study was to analyse the proximity of the vasculature to the TMJ region in TMJ ankylosis patients using magnetic resonance imaging (MRI).

Noncontrast-enhanced MRI images of seven patients were assessed. The distance between maxillary artery and neck of condyle/ankylotic mass was measured using coronal sections and distance between the internal carotid artery (ICA), internal jugular vein (IJV) and medial edge of condyle/bony mass were measured using axial sections.

The mean distance of internal maxillary artery (IMA) to medial edge of ankylotic mass was 1 ± 0.57 mm and 2 ± 1.2 mm-left and right condylar regions respectively (range: 0-4 mm).The mean distance from lateral aspect of ankylotic mass to IMA was 8.2 ± 1.4 mm and 8.7 ± 2.8 mm-right and left condylar regions respectively (range: 3-11 mm).The mean distance from medial edge of condyle to ICA was 18.8 ± 1.3 mm and 18.2 ± 1.1 mm-right and left condylar regions respectively (range: 17 mm-20 mm).The mean distance from the medial edge of condyle to IJV was 16.4 ± 1.1 mm and 14.5 ± 2.9 mm-right and left condylar regions (range: 11 mm-19 mm).

These measurements were used as a guide to plan the steps during surgery in order to minimise the intraoperative haemorrhagic complications. Hence, MRI may be considered as a valuable tool in assessing the juxtaposition of vascular bed to TMJ region, though contrast MRI and a larger sample is needed to standardise.