Temporomandibular joint (TMJ) disorders occur in many people and osteoarthritis (OA) is a severe form of this disease. Glucosamine has been used to treat OA of the large joints for many years and has been proved effective. A double-blinded randomized controlled trial was designed to investigate the effectiveness and safety of oral glucosamine hydrochloride pills combined with hyaluronate sodium intra-articular injection in TMJ OA.
One hundred forty-four participants with TMJ OA were randomized to 4 hyaluronate sodium injections and oral glucosamine hydrochloride (1.44 g/day) for 3 months (group A) or 4 hyaluronate sodium injections and oral placebo for 3 months (group B). All participants were followed for 1 year. Eighteen participants were lost to follow-up.
The intention-to-treat analysis showed that group A had similar maximal interincisal mouth opening and pain intensity during TMJ function at months 1 and 6 (P > .05). However, during long-term follow-up, group A had significantly greater maximal interincisal mouth opening compared with group B at month 12 (41.5 vs 37.9 mm; P < .001). For pain intensity, group A showed obviously lower visual analog scale scores than group B at month 6 (20.6 vs 29.2 mm; P = .007) and month 12 (17.4 vs 28.6 mm; P = .001). Twenty-four participants had gastrointestinal tract side effects, fatigue, and rash. Of these, 23 had slight side effects that were not correlated with glucosamine. There was no significant difference between the 2 groups (P > .05).
The results of this study suggest that, compared with hyaluronate sodium injection alone, glucosamine hydrochloride pills added to hyaluronate sodium injection had no meaningful effect on TMJ OA in the short-term but did relieve the pain caused by TMJ OA and improved TMJ functions in the long-term.