[Posterior vertical dimension and condylo-discal non-coordination of the temporomandibular joint. Hypothesis on correlation].

Background: On the basis of clinical evidence, an analytic study has been carried out to verify the hypothetic correlation between reduction of the posterior vertical overlap and internal derangements.

Methods: 58 patients with temporomandibular disorders have been observed; they presented clinically a reduction of the posterior vertical dimension (RPVD) due either to the loss of molar teeth or to the molar occlusal surface abrasion or to a wrong prosthetic rehabilitation. A cephalometric exam showed a significative correspondence between the RPVD and the retruded condylar position in the glenoidae fossa with a reduction of posterior joint space in comparison with the standard values purposed by Farrar.

Results: The results obtained showed a possible relation between occlusal alterations and the TMJ pathology.

Conclusions: The conclusion is drawn that the clinical evaluation brings to consider occlusal factors, and in particular the reduction of posterior vertical dimension may be considered as possible etiologic factors of TMJ disorders.