Ceiling effects, mechanistic mismatch, and the need for standardized reporting in autologous concentrates for temporomandibular joint disorders.

This letter addresses methodological considerations in a recent randomized controlled trial comparing platelet-rich plasma (PRP) and hyaluronic acid (HA) after temporomandibular joint (TMJ) arthrocentesis. We highlight a ceiling effect in which the control group achieved near-complete symptom resolution, leaving no room for adjunctive treatments to demonstrate superiority. We discuss the mechanistic mismatch between regenerative (PRP) and biomechanical (HA) approaches and emphasize the critical need for standardized PRP reporting. A systematic review found that only 10% of PRP clinical trials provided comprehensive protocol reporting. We recommend that future studies adopt minimum reporting standards, including relative centrifugal force, platelet concentration, leukocyte content, and activation method, to enable cross-study comparisons and advance the field toward precision medicine approaches in TMJ disorders.