Table 1.

The qualitative and quantitative measurements for primary and secondary outcomes utilised in the selected studies of this review, with consideration for TMJ synovial fluid analysis to evaluate the levels of oxidative stress, IL-1,6,8, TNF-α and β, MM-1,2,9, VEGF, TGF-β1 and IGF-I, for future extensive research. All the abbreviations in this table are listed in Supplementary File S2.

Assessment of Outcome Measures	Primary Outcomes	Secondary Outcomes
	Pain Reduction	Functional Improvement	Anxiety/Depression and QoL
Qualitative (patient-reported outcomes; subjective)	Visual analogue scale (VAS) Numerical scale of pain OHIP/TMD questionnaire McGill pain questionnaire Symptom severity index Orofacial myofunctional evaluation protocol with scores (OMES)	Patient-specific functional scale	Euro Qol-5D 5L Beck anxiety inventory (BAI) Pain distress scale
Quantitative (objective)	Kaplan–Meier method Pressure pain threshold (PPT) (dial algometer) Power algometer	Kaplan–Meier method Jaw kinesiology Craniomandibular index (CMI) Colorimetric capsules Electromyography (EMG) Digital pachymeter (Digimess) to measure the vertical and horizontal movements Stethoscope (crepitation) Helkimo index Anamnestic questionnaire Computerized photogrammetry Masticatory test Active range of motion (AROM) index Digital calliper Flexible millimetre ruler Millimetre ruler RDC/TDM
TMJ Synovial fluid analysis (immunological profile)	To evaluate the levels of the following data: oxidative stress, IL-1,6,8 (Interleukin-1,6,8), TNF-α (Tumor necrosis factor- alpha) and β, MM-1,2,9 (Mandibular movement-1,2,9), VEGF (Vascular endothelial growth factor), TGF-β1 (Transforming growth factor-β1), IGF-I (Insulin-like growth factor-I)