Dynamic somatosensory alterations in chronic painful temporomandibular myalgia disorders : a systematic review and meta analysis

Introduction : Patients with chronic myofascial Temporomandibular disorders (TMD) might exhibit widespread clinical pain, chronic pain and greater sensitivity to experimental pain than pain-free controls, suggesting an implication of somatosensory alterations. The purpose of this study is to to find evidence for deficient dynamic quantitative sensory testing (QST) involved in the physiopathology of TMD pain patients. Methods : The search strategy was conducted in MEDLINE/PubMed, EMBASE (including “Medline search”), SCOPUS, CINAHL and PsychINFO. Literature was screened and obtained by two independent reviewers. The methodological quality of the articles was examined using a SIGN checklist. Results : Twenty-four articles were retrieved for data extraction. Eleven studies demonstrated that TMDs enhanced pain responses to TS and 3 to CPM. We found evidence for mechanical TS in extra-trigeminal regions, for greater after sensations, hypoalgesia induced by stress and mixed evidence for CPM. Results of studies examining dynamical mechanisms are reflecting a pain physiopathology that is not fully understood.. Conclusion : This systematic review support the existence of spinal and central hyperexcitability found in TMD patients as shown by an increase in mechanical TS. Due to the inconsistent results concerning CPM, OA, EIH, PA, futur studies should be done.