Manual of Temporomandibular Disorders

Introduction

The cardinal signs and symptoms for temporomandibular disorder (TMD) are pain in the masseter muscle, temporomandibular joint (TMJ), and/or temporalis muscle regions; mouth-opening limitation; and TMJ sounds. TMD pain is by far the most common reason patients seek treatment.1,2

TMD is the second most common musculoskeletal pain, with low back pain being the first. It is most often reported in individuals between the ages of 20 and 40. Approximately 33% of the population has at least one TMD symptom, and 3.6–7% of the population has TMD with sufficient severity to cause patients to seek treatment.2–5

TMD symptoms generally fluctuate over time and correlate significantly with masticatory muscle tension, tooth clenching, grinding, and other oral parafunctional habits. TMD symptoms are also significantly correlated with an increase in psychosocial factors, for example, worry, stress, irritation, frustration, and depression.6–8 Furthermore, TMD patients with poor psychosocial adaptation have significantly greater symptom improvement when the dentist's TMD therapy is combined with cognitive-behavioral intervention.2,9

TMD symptoms generally fluctuate over time and correlate significantly with masticatory muscle tension, tooth clenching, grinding, and other oral parafunctional habits. TMD symptoms are also significantly correlated with an increase in psychosocial factors, for example, worry, stress, irritation, frustration, and depression.

TMD can cause other symptoms that are beyond the masticatory musculoskeletal system, for example, tooth pain, nonotologic otalgia (ear pain that is not caused by the ear), dizziness, tinnitus, and neck pain. TMD can contribute to migraine and tension headaches, muscle pain in the region, and many other pain complaints.10

Women request treatment more often than do men, providing a female–male patient ratio between 3:1 and 9:1.2 Additionally, TMD symptoms are less likely to resolve for women than for men.6,7 Many hypotheses attempt to account for the gender difference, but the underlying reason remains unclear.11

TMD symptoms are less likely to resolve for women than for men.

Knowledge about TMD has grown throughout the ages. In general, treatment philosophies have moved from a mechanistic dental approach to a biopsychosocial medical model with the integration of neuroscience literature. This is comparable to the treatment philosophies of other joint and muscle conditions in the body.3,12,13

Beneficial occlusal appliance therapy and TMJ disc-recapturing surgery were reported as early as the 1800s.12,14 The understanding of the importance to harmonize the occlusion for the health of the masticatory muscles and TMJs developed as the skills to reconstruct natural teeth advanced. As enthusiasm grew for obtaining optimum health, comfort, and function, the popularity of equilibrating the natural dentition also developed.12,15

In the 1930s, Dr. James Costen, an otolaryngologist, brought TMD into the awareness of physicians and dentists, and readers may still find TMD occasionally referred to as Costen's syndrome. Dr. Costen reported that TMD pain and secondary otologic symptoms could be reduced with alterations of the occlusion.16

Since TMD is a multifactorial disorder (having many etiologic factors), many therapies have a positive impact on any one patient's symptoms. Throughout much of the 1900s, many beneficial therapies were independently identified. Physicians, physical therapists, chiropractors, massage therapists, and others treating the muscles and/or cervical region reported positive responses in treating TMD symptoms. Psychologists working with relaxation, stress management, cognitive-behavioral therapy, and other psychological aspects reported beneficial effects with their therapies. Orthodontists, prosthodontists, and general dentists working with the occlusion also observed the positive impact that occlusal changes provided for TMD symptoms.

Surgeons reported positive benefits from many different TMJ surgical approaches. Many forms of occlusal appliance were tried and advocated, from which studies reveal there is similar efficacy for different appliance forms. Medications as well as self-management strategies used for other muscles and joints in the body were also shown to improve TMD symptoms. During this observational period, TMD therapies were primarily based on testimonials and clinical opinions, according to a practitioner's favorite causation hypothesis rather than scientific studies.12

Different philosophies appeared, with enthusiastic nonsurgeons “recapturing” discs through occlusal appliances, whereas surgeons repositioned the discs or replaced discs with autoplastic materials. The eventual breakdown of the autoplastic materials led to heartbreaking sequelae that caused many to step back from their narrowly focused treatment regimens and recognize the multifactorial nature of TMD and the importance of conservative noninvasive evidence-based therapies.12

Over the last 50 years, much was learned about basic pain mechanisms and the shared neuron pool of the trigeminal spinal nucleus, other cranial nerves, and cervical nerves. This provided a better understanding of the influence that regional and widespread pain may have on TMD, the similarities between chronic TMD pain and other chronic pain disorders, and the need for chronic pain management from a psychosocial and behavioral standpoint.8,17

Today, a large number of potentially reversible conservative therapies are available for our TMD patients. By using the information obtained from the recommended patient interview and clinical exam, practitioners can select cost-effective, evidence-based therapies that have the greatest potential to provide long-term symptom relief. The treatment selected often reduces a patient's contributing factors and facilitates the patient's natural healing capacity. This management is consistent with treatment of other orthopedic and rheumatologic disorders.2,3,10,13

Today, a large number of potentially reversible conservative therapies are available for our TMD patients.

We do not fully understand TMD and the mechanisms causing or sustaining it. Practitioners should bear in mind that not all TMD therapies are equally effective, and no one treatment has been shown to be best for all TMD patients. Most TMD patients can be managed successfully with reversible, conservative, noninvasive therapies by general practitioners, without using expensive, high-tech treatments.4,18–20

Most TMD patients who receive therapy obtain significant symptom relief, whereas patients who do not receive treatment have minimal symptom change.21

TMD therapy is generally recommended for patients who have significant temporal headaches, preauricular pain, jaw pain, TMJ catching or locking, loud TMJ noises, restricted opening, difficulty eating due to TMD, or nonotologic otalgia due to TMD.

To help your hygienists better identify patients in your practice who need your help, a recommended “Referral Criteria for Hygienists” is provided in Appendix 1.

References

1. Manfredini D, Guarda Nardini L. TMD classification and epidemiology. In: Manfredini D (ed.). Current Concepts on Temporomandibular Disorders. Chicago: Quintessence, 2010:25–39.

2. American Academy of Orofacial Pain. Temporomandibular disorders. In: de Leeuw R (ed.). Orofacial Pain: Guidelines for Assessment, Diagnosis and Management. 4th ed. Chicago: Quintessence, 2008:131–133, 161.

3. American Academy of Orofacial Pain. Introduction to orofacial pain. In: de Leeuw R, Klasser GD (eds.). Orofacial Pain: Guidelines for Assessment, Diagnosis and Management. 5th ed. Chicago: Quintessence Publishing Co, 2013:8, 130, 151.

4. Velly AM, Schiffman EL, Rindal DB, Cunha-Cruz J, Gilbert GH, Lehmann M, Horowitz A, Fricton J. The feasibility of a clinical trial of pain related to temporomandibular muscle and joint disorders: The results of a survey from the Collaboration on Networked Dental and Oral Research dental practice-based research networks. J Am Dent Assoc 2013;144(1):e1–e10.

5. Okeson JP....