Lessons Learned from a Headache TMD Study
Headaches are among the most common complaints in primary medical practice with a subset of headache complaints from individuals who are experiencing a temporomandibular dysfunction (TMD). Such headaches have been found to be associated with both internal joint pathology and muscle disorders.
TMD is a disorder encompassing a group of signs and symptoms that are usually localized to areas of the head and neck. This disorder can include a number of distinct clinical conditions such as myalgia, myositis, internal derangements of the temporomandibular joint, arthritic disorders, and craniofacial pain and dysfunction of multiple origins. Signs and symptoms can include headache, ear, face, neck, and jaw pain. These individuals often present with a reduced range of jaw motion often accompanied with deviations of jaw motion and unusual temporomandibular joint (TMJ) sounds.
The pathology of this disorder usually involves dysfunction in the TMJ proper. The etiology may originate from problems associated with the TMJ components such as the capsule, the ligaments, or the supporting osseous structures. These TMJ components have demonstrated referral of pain to the head and cervical areas.1-5 Pain can arise from disorders in these structures and can also be directly associated with subsequent protective muscle splinting or bracing. Sustained muscle activity associated with this bracing reaction leads to discomfort in these muscle groups. Rasmussen, et al., showed that a rise in intra-muscular pressure with sustained muscle contraction leads to mechanical compression of blood vessels with a resulting local ischemia.6 Metabolic alterations due to microcirculatory disturbances can result in localized pain.7
Palpation of these jaw and joint parts has demonstrated referral of pain to other areas of the head and neck. As problems in the health of these muscle groups grow, connected neuro-networks manifest pain to remote sites. In his recently published teaching text, Wright suggests “TMD patients tend to hold more tension in their masticatory muscles.” He demonstrates this referral phenomenon of pain in the head and neck area with many other clinical cases cited for study.8 Travell and Simon mapped the surprising extent of muscle referral patterns in their often-cited text of 1983.9 In fact, the symptoms of headache in this study were found in five different sites, namely, the frontal, temporal, occipital, vertex, and retro-orbital areas of the head and the cervical area.
The literature is replete with reports of an association of headaches and TMD. Various researchers have recognized headaches as a common symptom in individuals with TMD10-14 and a number of studies have noted a link between complaints of headache and TMD.14 Dawson noted that many patients with TMD reported incidence of headache. He found that headaches of the temporal muscle region were often related to TMD.2 It was also suggested that occipital headaches might be related to occlusal disharmony—a disruption of the stability of the craniomandibular complex. Farrar found that headache is the most common reported symptom of TMD, especially with patients showing internal derangements or degenerative arthritis. These headaches manifest as pain in the frontal, temporal, retro-orbital, and occipital areas—sometimes even with ear pain.15
Patients were selected using specific criteria in order to be included in this study. First, after presenting for care, a diagnosis had to have been made of having a temporomandibular disorder. Secondly, the patient must have made a concurrent complaint of headache. The charts of 546 consecutive patients originally diagnosed with TMD were examined to determine if headache was listed as a complaint. Sixty-five of the original patients (11.9%) did not have any headache symptoms reported and were removed from this study. The remaining group of 481 (88.1%) patients had their records examined.
These were divided into two groups, those reporting a history of trauma involving the head or neck (TG) and those reporting no such history of a trauma to the head or neck (NTG). The TG consisted of 254 patients and the NTG contained the remaining 227 patients. The records of both groups were inspected retrospectively to establish the locations and frequency of occurrence of headache complaints.
|# Referred Sites||1||2||3||4||5|
|Trauma Group (TG)||33||55||73||38||57|
|Non-Trauma Group (NTG)||89||70||41||24||3|
For our discussion, the pain of the cervical area was included and was designated as a cervical headache. A patient could have a headache in one area (ex. temporal) or in all five areas reviewed for this study. Headaches sites evaluated were the cervical, frontal, retro-orbital, temporal and vertex areas. Headache occurrence was charted as having one, two, three, four, or five specific sites per patient. Each patient’s combination of headache sites were noted. Thus, a patient having a headache at two sites (temporal and cervical) was different from another patient exhibiting pain in the retro-orbital and vertex sites. The total number of headache complaints per group, along with gender data, was tabulated and reviewed for trend assessment.
The TG was composed of 254 persons of which 195 were female (76.8%) and 59 were male (23.2%). This group reported a total of 589 headache complaints or 2.32 headaches per patient. In this TG, the temporal area accounted for 213 headache sites (83.9%) followed by 146 headaches of the cervical area (57.5%), then 141 in the frontal area (55.5%), then 104 in the retro-orbital areas (40.9%) and finally, 85 in the vertex area (33.5%).
The NTG consisted of 227 patients of which 182 were female (80.2%) and 45 were male (19.8%). This group had a total of 451 headache complaint sites or 1.99 complaints per patient. In this NTG, the temporal area again had the most frequent site noted at 168 or about (37.3%), followed by 99 in the retro-orbital areas (22.0%), then 82 in the cervical site (18.2%), then 70 in the frontal area (15.5%), and lastly, 34 in the vertex area (7.5%).
A comparison of number of referred sites per patient, as well as a frequency chart of the areas of referred pain for the trauma and non-trauma groups, are presented in Table 1 and Figure 1, respectively.