Purpose <p>The study compares the effect of repeated intra-articular injection of Tenoxicam versus Meloxicam after arthrocentesis on modulating the symptoms of TMJ anterior disc displacement with reduction (ADDWR).</p> Methods <p>Thirty patients were recruited for this randomized controlled trial. They were randomly and equally allocated to two groups. After arthrocentesis, patients received three injections at one-month intervals with either Tenoxicam (Tx group) or Meloxicam (Mx group), while Visual Analogue Scale (VAS), maximal interincisal opening (MIO), and TMJ clicking were measured preoperatively and at one, three, six, and nine months postoperatively.</p> Results <p>While both groups showed significant improvements in pain and increased MIO, the improvement in the Tx group was significantly greater than that in the Mx group. After symptom alleviation during the one- to three-month interval, pain gradually increased from the third month onward in both groups. At the same time, MIO began to decrease from the sixth month in the Mx group and the ninth month in the Tx group. The correlations between pain reduction and both MIO and clicking in the Tx group were statistically significant (<i>p</i> &lt; 0.001*) &amp; (<i>p</i> = 0.004*), respectively, compared to statistically insignificant correlations among the Mx group (<i>p</i> = 0.295) &amp; (<i>p</i> = 0.266). Nevertheless, both groups showed no significant improvement in the clicking bypass.</p> Conclusion <p>The successive injections of both Tenoxicam and Meloxicam after arthrocentesis were effective; while Tenoxicam offered superior statistical pain reduction and enhanced mouth opening, the substantial clinical benefit (SCB) of both drug injections was equivalent.</p> Trial registration <p>The study was registered on <a href="http://www.clinicaltrials.gov">www.clinicaltrials.gov</a> (#: NCT06403046) on May 7, 2024.</p>