Patients with restored occlusions. Part I: TMJ dysfunction determined by a pantographic reproducibility index

In a population of 50 subjects restored with fixed prostheses, the prevalence of TMJ dysfunction was 38% slight, 20% moderate, and 10% severe for a total of 68% showing some degree of dysfunction as recorded by pantographic tracings quantitated by the PRI. SD varied between categories. Higher PRI scores produced larger SD. The SD was 2.96 for the reproducible category, increasing progressively in each category, to 12.91 for the severe dysfunction category. The one session (four sets of tracings) used in the study to determine the degree of TMJ dysfunction appeared to be an accurate sample of a subject's PRI score for a given time. Control subject's scores appeared to stay relatively stable (p = .3649) over a period of time (1 to 3 months). While the scores did fluctuate, the category remained essentially the same. Those subjects with higher PRI scores showed the most fluctuation. The results indicated that pantographic tracings quantitated by the PRI can be used as a suitable instrument in epidemiologic studies to determine the prevalence of TMJ dysfunction.