The Relationship Between Temporo-mandibular Joint Dysfunction and Widespread Pain: A Cross-sectional Study.

This cross-sectional study aims to study the relationship between temporomandibular joint dysfunction and widespread pain syndromes. 

After obtaining ethical approval 54 patients were eligible to participate in the study. Patients were included if experiencing diffuse pain for more than six months, diagnosed with a widespread pain syndrome, experiencing jaw pain or TMJ dysfunction, is older than 18, can provide a written informed consent. Patients were excluded if they have surgical history, systematic disease, specific diagnosis for pain, neurological conditions, a hearing or visual impairment. Fonseca's Questionnaire was used for temporomandibular related signs and symptoms. Symptom Severity Scale was used to assess symptom severity and intensity. Finally, Widespread Pain Index was used to assess pain regions and localization. IBM SPSS version 21 was used to perform statistical analysis chi-square, Linear correlation, and ANOVA were run with p-value set at 0.05. 

Participants were of an average age of 27.87, with a moderate distribution between 40% males and 60% females. Most participants reported co-occurring neck pain and headaches in addition to jaw pain (57%). A statistically significant Pearson association between cranio-mandibular pain and headaches was found (p=0.03). A strong positive statistically significant association exists between cranio-mandibular pain and feeling tense (p=0.01). There is a strong positive linear correlation between symptom severity scale and widespread pain index, which was highly significant. (p= 0.003). The average of symptom severity score differs very highly significantly between the subgroups with TMJ pain according to ANOVA (p= 0.001). The average of WPI final score differs highly significantly between the subgroups with TMJ pain according to ANOVA (p = 0.004). 

There is a positive moderate correlation between TMJ dysfunction and widespread pain disorders in terms of pain localization, distribution, symptom severity, and TMJ manifestations, with most prominent associated manifestations being headache, sleep disturbances, feeling tense, teeth grinding, and digestive issues. Furthermore, pain was most experienced in the shoulders, neck, jaw, in addition to back. Significant correlations were detected between wide-spread pain index and jaw pain in addition to symptom severity and jaw pain explaining the presence of a relation at the anatomical, physiological, and psychological levels. 

 This study may assist in identifying the mechanisms behind the found relationship, proposing assessment and diagnostic methods, and new advances in evidence-based treatments aiming to target the anatomical and physiological causes for successful management.