The objective of this observational study was to establish the possible presence of confounders on the association between temporomandibular disorders (TMD) and headaches in a patient population from a TMD and Orofacial Pain Clinic.
Several subtypes of headaches have been diagnosed: self-reported headache, (probable) migraine, (probable) tension-type headache, and secondary headache attributed to TMD. The presence of TMD was subdivided into 2 subtypes: painful TMD and function-related TMD. The associations between the subtypes of TMD and headaches were evaluated by single regression models. To study the influence of possible confounding factors on this association, the regression models were extended with age, sex, bruxism, stress, depression, and somatic symptoms.
Of the included patients (n=203), 67.5% experienced headaches. In the subsample of patients with a painful TMD (n=58), the prevalence of self-reported headaches increased to 82.8%. The associations found between self-reported headache and (1) painful TMD and (2) function-related TMD were confounded by the presence of somatic symptoms. For probable migraine, both somatic symptoms and bruxism confounded the initial association found with painful TMD.
The findings of this study imply that there is a central working mechanism overlapping TMD and headache. Health care providers should not regard these disorders separately, but rather look at the bigger picture to appreciate the complex nature of the diagnostic and therapeutic process.
*Education of Physiotherapy, ACHIEVE—Centre of Applied Research, Faculty of Health, Amsterdam University of Applied Sciences
‡Department of Rehabilitation, Academic Medical Center, University of Amsterdam
§Department of Oral Health Sciences, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, Research Institute MOVE Amsterdam, Amsterdam
†Radboud University Medical Center, Research Institute for Health Sciences, IQ Healthcare, Nijmegen
∥Department of Oral-Maxillofacial Surgery, Prosthodontics and Special Dental Care
¶Physical Therapy Science, Clinical Health Sciences, University Medical Center Utrecht, Utrecht, The Netherlands
Supported by the Dutch Organization for Scientific Research (Nederlandse Organisatie voor Wetenschappelijk Onderzoek—NWO) (grant number 023.006.004) the Hague, Netherlands. The authors declare no conflict of interest.
Reprints: Hedwig A. van der Meer, PT, MSc, Amsterdam University of Applied Sciences, Tafelbergweg 51, Amsterdam 1105 BD, The Netherlands (e-mail: firstname.lastname@example.org).
Received May 3, 2016
Received in revised form January 16, 2017
Accepted December 8, 2016