Developing a measurement of treatment outcomes in Temporomandibular disorders (TMD)

Clinical research in TMD suffers from the lack of an outcome measure that is able to measure the impact of treatment on patients' quality of life. Objectives: This study takes the first steps to identify the potential composition of such an indicator using the Oral Health Impact Profile (OHIP) as a starting point. Methods: OHIP, which contains 49 items in 7 domains, each scoring on a five point scale (5 units: 0-4) related to frequency of impact, was administered to 110 TMD patients, diagnosed using Research Diagnostic Criteria prior to any intervention, and 110 age and sex matched controls with no history of TMD. The 49 individual item scores and the combined scores for the domains were compared using Mann-Whitney U test. Scores for each item were calculated in 4 ways (median, mean, % occurring fairly or very often-FOVO, item impact) and groups were compared. The concept of a clinically significant difference in scores for each item was explored by using different thresholds for clinical significance. Results: All item scores were higher for patients than controls, with 41 items showing differences between groups at p<0.01. The remaining 8 items were not obviously related to TMD (denture problems, aesthetics). All seven OHIP domains also showed highly significant differences in scores between patients and controls (p<0.001). The range of difference between groups for individual items was 0-3 (Median), 0.03-2.7 (Mean), 1-67% (FOVO), 0.17-205 (item impact). Clinically meaningful thresholds were defined as >2 units difference (median) and >1 unit (mean). Items which reached the thresholds were cross-checked against top scoring items in FOVO and item impact. Sixteen items were identified and were consistently top scoring. Conclusions: There are profound differences between TMD patients and healthy controls in OHIP scores. Items with the greatest differences may form the basis of a clinical outcome measure.