THE EFFECT OF POSTERIOR TOOTH GUIDANCE ON NONWORKING SIDE ARBITRARY CONDYLAR POINT MOVEMENT

Occlusal form is frequently modified in clinical practice and yet we d o not have detailed knowledge of the possible effects of these changes on condylar movement. The aim of this study was to quantify the effec ts of an alteration in the occlusion on condylar movement during a lat eral excursive jaw movement. Posterior tooth guidances (i.e. metal ove rlays) were attached to both maxillary first molars. The movement of a rbitrary condylar points on the non-working side was recorded in seven subjects during lateral excursion under natural tooth guidance (contr ol) and was compared with that after placement of the overlays (guidan ce). The guidance resulted in statistically significant changes to the displacement of the arbitrary condylar points on the non-working side . For example, at a standardized (3 mm) displacement along the mid-inc isor point trajectory during the lateral excursion for both control an d guidance in all subjects, the corresponding displacements of the con dylar points were statistically significantly decreased under the guid ance situation in comparison with the control situation. These data su ggest that, for the same magnitude of mandibular displacement during l ateral excursion, the introduction of a posterior tooth guidance limit s condylar displacement on the non-working side.