This study evaluated and compared the clinical outcomes of intra-articular medical ozone therapies at 15 μg/L and 30 μg/L concentrates and non-ozone treatment for treating temporomandibular joint osteoarthritis (TMJ-OA). The sample was composed of 48 patients, and they were randomly divided into three groups with equal numbers: the control group received only four sessions of intra-articular anesthesia (group 1), and the study groups received four sessions of 15 μg/L (group 2) or 30 μg/L (group 3) concentrated intra-articularly deposited medical ozone following the intra-articular anesthesia. The primary outcome variables were recorded preoperatively and 3 and 12 months postoperatively. The final sample comprised 11 patients in group 1, 16 in group 2, and 11 in group 3. The mean follow-up period was 13.56 ± 2.08 months. Significant improvements were observed in masticatory efficiency and MIO only in the study groups, as well as pain complaints, joint sounds, and pain at lateral palpation of TMJ in all groups. Study groups showed superior outcomes compared to the control group. Only masticatory efficiency increased significantly more in Group 3 than in Group 2. Despite the limited sample size, the present study's findings suggested that intra-articular medical ozone therapy produced superior outcomes compared to control groups for treating TMJ-OA. Both ozone doses produced significant and similar improvements in clinical outcomes, with the exception of masticatory efficiency.