[Linear tomography and the Zonarc TMJ program. Reproducibility of condylar position of TMJ after surgical correction of dysgnathia].

Abstract

In this clinical study the position of the mandibular condyles of 40 patients treated for malocclusion by surgical splitting of the mandibular ramus alone or combined with Le Fort I osteotomies was studied on lateral linear TMJ tomograms. Linear tomograms of the right and left TMJ with the mandible closed were taken from each patient prior to surgery and 6 months postoperatively. The postoperative changes in condylar position wee assessed in terms of direction and amount. Condylar displacements were found in 89% of the examined joints, most of them were less than 2mm. All types and combinations of displacement occurred, however, general trends in direction depending on the type of treatment could not be established with statistical significance. The type of surgical correction, its direction and amount did not seem to have an effect on the direction and amount of condylar displacement resulting. A comparison of the measured values with data in the literature showed that the amount of condylar displacement was markedly less--this seemed to be attributable to our precise evaluation method and a more sophisticated surgical technique.