OBJECTIVE: The most common cause of orofacial pain of non-dental origin is temporomandibular disorders (TMD); a heterogeneous group of myoarthropathies manifested by dysfunction of the temporomandibular joint (TMZ), masticatory muscles, and associated surrounding structures. Multifactorial etiology includes a number of genetic / biological, behavioral, environmental, socioeconomic, and cognitive factors. The main symptoms are pain and dysfunction, and the change of disorders from acute to chronic phase results in reduced daily working ability and impaired emotional and social characteristics of the individual, thus impairing quality of life, creating fertile ground for disorders such as anxiety and depression. The main goal in the treatment of TMP is pain relief and the establishment of normal mandibular function with a consequent improvement in quality of life. That 50-90% of patients are relieved of pain by such an approach. The aim of this study was to compare the effectiveness of educational intervention, which includes educating patients about pain and reduction of muscle activity, while performing physical therapy, with stabilization splint and placebo splint therapy in patients with chronic TMP and examine the impact of oral parafunctions on therapeutic success as it is known that patients with more frequent parafunctions and patients diagnosed with temporomandibular pain (according to the DC / TMD protocol) are more sensitive to occlusal changes compared to healthy patients. METHODS: Out of a total of 84 participants who met the criteria, 45 agreed to participate in the survey, while 30 completed the survey. All participants were female with a mean age of 36 years (± 10.51). The study was designed as a controlled randomized single-blind study, and participants were randomized into 3 groups: educational intervention with exercise (EwE), stabilization splint (SS), and placebo splint (PS) with a predicted distribution ratio of 1:1:1. Participants were clinically treated according to the Diagnostic Criterion for Temporomandibular Disorders (DC / TMD). Primary (spontaneous pain according to visual analogue scale (VAS) and characteristic pain intensity score (CPI) from the Graded Chronic pain scale) and secondary outcome measures (pain-free opening, maximum unassisted opening, oral health related quality of life (OHIP-14), perceived stress (PSS), generalized anxiety (GAD-7) and functional limitation (JFLS) were evaluated during six-month treatment period. In addition, patients of all three groups were divided into 2 groups: a “high- frequency parafunction” (HFP) group with an OBC score >25 and a “low-frequency parafunction” (LFP) group with an OBC score of 0-25. RESULTS: In patients treated with EwE, there was a significant reduction in the intensity of chronic pain (F=27.25; p=0.0005,), while CPI values in the SS and PS group did not change significantly compared to the initial measurement. The amount of pain-free opening increased significantly in the EwE and SS groups compared to the PS group (after 3 months: F=3.737, p=0.040, after 6 months: F=6.665, p=0.005). Within- group analyses showed a significant reduction in perceived stress (Wilks Lambda=0.42, p=0.03), degree of anxiety (F=3.55, p=0.049) and functional limitation (F=19.84, p=0.001) and improvement in oral health-dependent quality of life (Wilks Lambda=0.29, p=0.007) only in the EwE-treated group. Patients in HFP group had a significantly higher degree of anxiety (3rd month: p=0.002; 6th month: p=0.014) than patients in LFP group. Withingroup analysis showed a significant reduction in anxiety (Wilks Lambda=0.65, p=0.042) and stress (Wilks Lambda=0.63, p=0.033) and an improvement in functional limitation (F=16.60, p<0.0001) only in patients HFP group. Oral health-dependent quality of life after 6 months of treatment improved significantly only in patients with HFP (Wilks Lambda=0,34, p=0.0003). CONCLUSION: Educating patients about the disorder in combination with exercise has been shown to be a more effective therapeutic modality than stabilization and placebo splints in relieving pain and improving mouth opening during the six-month treatment period. When assessing the effectiveness of therapy, it is important to consider thepresence of parafunctional habits. Therapeutic efficacy, which is reflected as a significant reduction in anxiety, stress, and functional limitations in the highintensity parafunction group, was observed regardless of the therapy administered.