E2 ModerateModerate confidencePEM not requiredCross-SectionalPeer-reviewedReviewed
Specific and number of comorbidities are associated with increased levels of temporomandibular pain intensity and duration.
Dahan, Haissam, Shir, Yoram, Velly, Ana et al. · The journal of headache and pain · 2015 · DOI
Quick Summary
This study examined how jaw pain (temporomandibular disorder) relates to other chronic pain conditions, particularly in people with ME/CFS. Researchers found that people with jaw pain who also had migraine or ME/CFS experienced more severe and longer-lasting jaw pain. Having multiple pain conditions at the same time was linked to worse jaw pain symptoms.
Why It Matters
ME/CFS frequently co-occurs with multiple pain conditions, and this study provides evidence that accumulating comorbidities may worsen symptom burden and disease presentation. Understanding these relationships helps clinicians recognize and address interconnected pain syndromes in ME/CFS populations, potentially informing more comprehensive treatment approaches.
Observed Findings
- - Increasing number of comorbidities was positively associated with TMD pain intensity (p < 0.01) and duration (p < 0.01)
- - Migraine presence was associated with increased TMD pain intensity (p < 0.01)
- - ME/CFS presence was associated with increased TMD pain intensity (p < 0.05) and duration (p < 0.01)
- - In myofascial pain subgroup, associations remained significant; in non-myofascial group, only comorbidity number-duration relationship persisted
Inferred Conclusions
- - Comorbidity burden is a significant factor in TMD pain presentation
- - Migraine and ME/CFS specifically contribute to worse TMD pain outcomes
- - The relationship between comorbidities and TMD pain may differ between myofascial and non-myofascial TMD subtypes
Remaining Questions
- - What mechanisms underlie the associations between ME/CFS and TMD pain severity?
- - Does treating one condition (e.g., migraine) improve TMD pain outcomes in comorbid patients?
- - Are the associations bidirectional, or does TMD worsen comorbid conditions?
- - How do demographic and psychosocial factors mediate these relationships?
What This Study Does Not Prove
This cross-sectional design shows associations but cannot establish whether comorbidities cause worse TMD pain, whether TMD causes worse comorbid symptoms, or whether shared underlying mechanisms drive all conditions simultaneously. The study does not prove causality and cannot determine temporal relationships between condition onset.
Tags
Symptom:PainFatigue
Method Flag:No ControlsSmall Sample
Metadata
- DOI
- 10.1186/s10194-015-0528-2
- PMID
- 26002637
- Review status
- Editor reviewed
- Evidence level
- Single-study or moderate support from human research
- Last updated
- 12 April 2026
About the PEM badge: “PEM required” means post-exertional malaise was an explicit required diagnostic criterion for participant inclusion in this study — not that PEM was studied, observed, or discussed. Studies using criteria that do not require PEM (e.g. Fukuda, Oxford) are tagged “PEM not required”. How the atlas works →
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