Temporomandibular Joint Referred Pain
Temporomandibular Joint Dysfunction (TMD) is a disorder of the muscles of mastication, the TM joints, and related ligaments and tendons. TMD may be characterized by any of the following: pain in the jaw moving muscles or in the TM joints, joint noises, mandibular restrictions, and/or deviations with jaw movement. Symptoms include headaches, facial and jaw pain in addition to ear and neck complaints.
A number of studies have found referred pain to distal sites to be associated with internal TM joint disorders.1-6 Additionally, Danzig et al found that an anesthetic injection into the temporomandibular joint space of patients with TMD decreased the pain located in the head, facial and neck regions on the ipsilateral and contralateral sides.7 Montgomery and co-researchers reviewed fifty-one subjects that had temporomandibular joint disc repositioning surgery and found they experienced a significant decrease in headaches, TMJ pain, ear pain, and neck/shoulder pain.8 Steigerwald et al assessed forty-three patients who underwent arthroscopic surgery for arthrogenous TMJ to determine what effects the surgery had on their symptoms of headache, neck pain, shoulder pain, dizziness and tinnitus. They found a significant symptom reduction for all symptoms reviewed on these patients. They suggested that a substantial number of these symptoms were created by temporomandibular joint pathology acting on central neural processes.9
The sipila and co-workers study concluded that facial pain can be associated with TMD as well as pain and muscle tenderness in the neck area.10 Cimino et al revealed that neck and shoulder symptoms are frequently seen in subjects that they evaluate with mandibular dysfunction.11 de Wijer et al concluded that the function of the masticatory system should be evaluated in patients with neck complaints in order to rule out a possible involvement of the masticatory system.12 Mahan and Alling suggested that pathological changes in the TM joint can refer pain to the orbit that has a lancinating or piercing quality.13 Subjects with TM dysfunction can have pain that radiates to the ear, temporal, ramus, neck and other areas.6
TM joint pain can arise from a number of primary and referred sources. The examiner should be aware that the area of pain may — or may not — be source of the subject's presenting pain complaint.14,15 Usually a thorough history and clinical evaluation will determine if the TM joint pain is from arthrogenous or myogenous causes, or both. Arthralgia is a term used to describe pain that originates from a joint. There are several types of pain can originate from the TM joint structures (see Table 1).
Acute TM joint pain can induce a defensive muscle response called protective muscle splinting which is a myalgia-type pain. Pain from muscle trigger points can be referred to the TM joint in addition to other areas.
The sternocleidomastoid, masseter, medial pterygoid, and lateral pterygoid muscles may also refer pain to the TM joint, especially when myofascial trigger points are involved. Trigger points can develop from painful temporomandibular joint conditions such as inflammation, displaced disc disorders and osteoarthritis. Other syndromes such as temporal tendonitis and Ernest syndrome have the TM joints in their zone of referral.16 The main objective of the examination is to identify the source of pain and reach a diagnosis.17
Non disc-reducing disorders
The charts of 445 consecutive patients who reported with TM Dysfunction had their charts reviewed retrospectively to investigate if referred TMJ pain was present. Those charts with positive findings of referred pain had the sites of referral noted. The following sites were found to have referred pain: head, face, ear, mandible, neck, eyes, and teeth.
The examination for referred pain was done using Okeson's method of applying firm continuous pressure over the TM joint lateral poles (see Figure 1), and the retrodiscal areas (see Figure 2), for a few seconds.2 This allows the examiner to elicit a pain referral pattern, if one existed, and provided an opportunity to reproduce the subject's chief complaint.14
Of the 445 TMD pain subjects examined, 388 (87.1%) were found to have referred TM joint pain. The sites of referral and prevalence are noted in (Table 2). The results showed that 160 (41.2%) had referred temporal pain, 124 (31.9%) had referred facial pain, 78 subjects had (20%) had referred ear pain, 35 (9%) had referred mandible pain, 22 (5.6%) had referred neck pain, 14 (3.6%) had referred eye pain, and two (
Patients with internal TM joint pain and pathology may experience referred pain symptoms. These pains can emanate from the joint itself or from myogenic trigger points. A number of studies have shown a correlation between the TM joint and the identified sites of referred pain found in this study. Head pain was the most common finding in this study and this correlates with findings of others.1-6 There are multiple areas in the TM joints from which referred pain can originate. These are the discal ligaments, retrodiscal tissues (posterior attachments), and articular capsules. Osteoarthrosis of the TM joint comprises a fourth source of dysfunction.