OBJECTIVESThe aim of this study was to compare the effectiveness of using Ping On ointment and using petroleum jelly in the treatment of temporomandibular joint (TMJ) and masticatory muscle pain, in order to establish the true efficacy of Ping On ointment.METHODSIn this randomized, double-blinded, placebo-controlled trial, 55 subjects with TMJ and/or masticatory pain (Group I patients according to the Research Diagnostic Criteria for Temporomandibular Disorder (RDC/TMD) received Ping On ointment for 4 weeks, or placebo for 4 weeks. Subjects were evaluated with standard measures of efficacy: pain intensity measured by visual analogue scale and maximal comfortable mandibular opening, at baseline and again after 4 weeks of treatment.RESULTSPing On ointment significantly reduced the symptoms of painful TMJs and/or masticatory muscles. Maximal comfortable mandibular opening also improved in the Ping On ointment group compared with the placebo, but was not clinically significant.CONCLUSIONSThis preliminary study suggests that topical application of Ping On ointment may be considered for further investigation as a potential first-line treatment modality, before prescribing analgesics, for the management of TMDs. It is topically applied, safe, reversible, and effective in managing TMDs and masticatory muscle pain.