Functional occlusal relationships in a group of post-orthodontic patients: preliminary findings

This study investigated features of the functional occlusion in a group of 37 patients immediately following two-arch fixed appliance treatment. Study casts were mounted in the retruded axis position on a semi-adjustable articulator and occlusal contacts were recorded with articulating paper in retruded and lateral mandibular positions. The magnitude of the slide between the retruded axis position and the intercuspal position was measured to the nearest 0.5 mm in the antero-posterior, vertical and lateral directions. The results revealed that the majority of subjects had a unilateral contact on initial closure in the retruded axis position, and a slide between this position and the intercuspal position. Most subjects demonstrated canine guidance on the working side in lateral positions. In addition, however, most subjects had contact between the second molars on the non-working side. Based on current concepts of functional occlusion, this group of post-orthodontic patients did not exhibit ideal occlusal relationships. The long-term implications of this finding are unclear, but may be associated with post-orthodontic instability, tooth wear and temporomandibular disorders. A long-term follow-up is planned to attempt to clarify some of these issues.