1739 Occlusal alterations influence multiple ipsilateral condylar points' movements during laterotrusion
B.-Y. HUANG1, C.W.L. JOHNSON1, C.J. DURRANT2, and G.M. MURRAY1, 1University of Sydney, Westmead,NSW, Australia, 2University of Sydney, NSW, Australia

Dental restorations often change tooth shape; however, there is little information about their effect on temporomandibular joint function. Previous studies of the effect of an occlusal alteration (OA) on condylar movements used only one point to represent the condyle, a 3-D object. Objectives: This study investigated the effect of a reversible OA on the tracings of multiple condylar points during laterotrusion. Methods: From 3 healthy subjects, CT scans were used to determine 5 ipsilateral anatomical condylar points (accuracy: ~0.5 mm): most superior, most anterior, and most posterior points, and lateral and medial poles. Jaw movements were controlled by visual feedback and recorded, in 6 d-of-f, using JAWS3D. 10 trials of right jaw movement were repeated under 3 conditions: Control 1 (before OA), OA (on right side), and Control 2 (after OA removal). Each trial had 5 phases: intercuspal position (IP) (2.6 s), outgoing (1.9 mm/s), holding (2.6 s), return (1.9 mm/s), and IP (2.6 s). Results: In all 3 subjects, OA caused a significant (p<0.05) change in condylar tracings at 6th mm of mid-incisal point displacement (MIPD) from IP for outgoing and return phases. At 3rd mm of MIPD, OA significantly altered condylar tracings at outgoing (n=2) and return (n=1) phases. At outgoing phase (n=1), OA changed the direction of movement supero-inferiorly in all points except the medial pole. Conclusions: The results suggest that an OA changes ipsilateral condylar movement. Supported by Australian Prosthodontic Society, Inc. and Australian Dental Research Foundation, Inc. bhuang@mail.usyd.edu.au

Seq #166 - TMJ - Structure and Function I
9:00 AM-11:00 AM, Friday, 8 March 2002 San Diego Convention Center Room 16A (Mezzanine Level)

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