Effect of increased posterior displacement of the glenoid fossa on mandibular growth: a methodological study on the rabbit

In order to study the adaptive changes in the masticatory apparatus an increased posterior displacement of the fossa was artificially provoked in young rabbits by a combined effect of the growth of the neurocranium and artificial craniosynostosis. As a reaction to an increased posterior migration of the fossa the mandible had grown longer and the growth of the condylar cartilage increased. The resorptive process at the anterior aspect of the condyle appeared more rapid than the apposition at the posterior aspect. In spite of the increased condylar growth, the condyles were located more anteriorly and inferiorly in relation to fossa from 5 days post-operatively onwards. However, no differences in intermaxillary relationships were observed between control and experimental animals in any phase of the observation period. The results indicate that the tissues, for instance muscles, connecting the mandible to neighbouring structures, are more important than growth of the condyle in determining the sagittal intermaxillary relationship.