The hyperdivergent facial morphology may play a role in the development of TMJOA. The stability of the TMJ disc depends on the integrity of the joint ligaments and the forces applied over the TMJ. Hyperdivergent facial morphology is prone to disc displacement because of the poor reciprocal fitting of the articular surfaces, that is, less contact area is observed between condylar head and glenoid fossa compared with hypodivergent facial morphology [27 ].
Source: wiktionary