Hyaluronate for temporomandibular joint disorders.

BACKGROUND Temporomandibular joint disorders (TMD) refer to a group of heterogeneous pain and dysfunction conditions involving the masticatory system, reducing life quality of the sufferers. Intra-articular injection of hyaluronate for TMD has been used for nearly two decades but the clinical effectiveness of the agent has not been summarized in the form of a systematic review. OBJECTIVES To assess the effectiveness of intra-articular injection of hyaluronate both alone and in combination with other remedies on temporomandibular joint disorders. SEARCH STRATEGY Intensive electronic and handsearches were carried out. The Oral Health Group's Trials Register (September 2001), The Cochrane Library CENTRAL database (Issue 3, 2001), MEDLINE (1966- May 2001), PubMed ( up to March 2002), EMBASE (1974 - August 2001), SIGLE (1980 - December 2001), CBMdisc (1983 - July 2001, in Chinese) and Chinese Medical Library were searched. All the Chinese professional journals in the oral health field were handsearched and conference proceedings consulted. There was no language restriction. SELECTION CRITERIA Randomized or quasi-randomized controlled trials (RCTs), with single or double blind, design testing the effectiveness of hyaluronate for patients with temporomandibular joint disorders. DATA COLLECTION AND ANALYSIS Two reviewers independently extracted data, and three reviewers independently assessed the quality of included studies. The first authors of the selected articles were contacted for additional information. MAIN RESULTS Seven studies were included in the review. Three studies, including 109 patients with temporomandibular disorders, compared hyaluronate with placebo. Long term effects (three months or longer) are in favour of hyaluronate for the improvement of clinical signs/overall improvement of TMD (RR=1.71, 95%CI: 1.05, 2.77) from two of the studies (n=71). However, this conclusion was not stable enough at sensitivity analysis. Three studies provided data from 124 patients for the comparison of hyaluronate with glucocorticoids (one study also included a placebo group). Hyaluronate had the same short term and long term effects on the improvement of symptoms, clinical signs or overall conditions of the disorders as glucocorticoids. When comparing the effect of arthroscopy or arthrocentesis with and without hyaluronate, results were inconsistent. Hyaluronate had a potential in improving arthroscopic evaluation scores. Mild and transient adverse reactions such as discomfort or pain at the injection site were reported in the hyaluronate groups. No quality of life data were reported REVIEWER'S CONCLUSIONS There is insufficient, consistent evidence to either support or refute the use of hyaluronate for treating patients with TMD. Further high quality RCTs of hyaluronate need to be conducted before firm conclusions with regard to its effectiveness can be drawn.