To compare the clinical efficacy of arthrocentesis, intra-articular platelet-rich plasma (PRP) injection, and combined arthrocentesis with PRP in treating arthralgia of the temporomandibular joint (TMJ).

A retrospective study included 75 patients with TMJ disorders who underwent arthrocentesis (n=25), PRP injection (n=25), or arthrocentesis combined with PRP (n=25). Clinical outcomes were assessed preoperatively and at 1 and 6 months postoperatively, including TMJ pain, masticatory pain, masticatory efficiency, joint sounds, maximum mouth opening (MMO), mandibular protrusion and lateral movements, and temporalis and masseter tenderness. Intra-group changes were analyzed with the Friedman test, and intergroup comparisons with the Kruskal–Wallis test and Bonferroni-corrected post hoc analyses.

All three methods significantly improved pain, masticatory efficiency, and MMO over the 6-month follow-up (p<0.001). No significant intergroup differences were found in joint sounds, MMO, or protrusion movement (p>0.05). However, lateral mandibular movement and temporal muscle tenderness showed significant differences between the groups at all time points (p < 0.001); these differences can be attributed primarily to baseline heterogeneity in the PRP group. At the 6-month mark, TMJ pain scores showed a statistically significant difference between the groups overall (p=0.017); In post-hoc comparisons, the combination group showed numerically lower pain than the arthrocentesis group, but this difference did not reach the pre-specified Bonferroni-corrected significance threshold (adjusted p = 0.027 vs. α = 0.017). Throughout the follow-up period, the PRP group had significantly higher masticatory pain and lower masticatory efficiency compared to the combination group. Preoperative differences in temporalis tenderness and lateral movements limited the interpretation of these findings.

All three treatments provided clinical benefit for TMJ arthralgia. The use of PRP in combination with arthrocentesis has shown superior efficacy compared to PRP alone, particularly in terms of masticatory pain and masticatory efficiency; however, this does not hold true for temporomandibular joint pain (the primary outcome), and the difference between the groups did not reach statistical significance. Given the significant baseline heterogeneity in the PRP group, these findings regarding pain should be interpreted with caution. Prospective randomized controlled trials with larger sample sizes and longer follow-up periods are needed.