Temporomandibular disorders (TMD) are a common musculoskeletal dysfunction of the masticatory muscles, joints and associated structures of the temporomandibular joint (TMJ). They can be subdivided into two broad syndromes: (1) muscle-related, or myogenous TMD, and (2) joint-related, or arthrogenous TMD, secondary to true articular disease. These syndromes can occur separately or simultaneously, often making diagnosis and treatment challenging.
TMD can be caused by:
- Myofascial pain dysfunction (temporalis, masseter, lateral and medial pterygoid)
- Internal derangement of the joint space (trauma, muscle hyperactivity, condylar restriction, anterior crowding of teeth, disc perforation or displacement)
- Degenerative joint disorders (rheumatoid arthritis, psoriasis, pseudogout, ankylosing spondylitis and lupus erythematosus)
- Psycho-physiologic factors (stress, tension, depression, habitual clenching, grinding of the teeth or fingernail biting)
- Mal-alignment of the jaws or internal components of the joint space.
Epidemiology including risk factors and primary prevention
Symptoms of TMD are common in all age groups.1 Incidence of TMD increases with age, with a peak incidence of 4.5% within the 35-44 year old age range.1 TMDs are significantly more common in females than in males, with population-based studies indicating that females are at approximately twice the risk of experiencing a TMD as males.2 Age has also been shown to be a factor in the incidence of TMDs, with peak prevalence occurring in women in the 35–44 age group.3 The association of race/ethnicity with TMDs is currently not well understood.4
The temporal mandibular joint (TMJ) is a synovial articulation between the condyle of the mandible and the squamous portion of the temporal bone. Innervation is supplied by the branches of the mandibular nerve (auriculotemporal and posterior temporal nerves). Vascular supply to the TMJ is primarily supplied by the superficial temporal and maxillary branches of the external carotid, with other smaller contributing branches.
The cause and underlying pathophysiology of TMD has evolved over the years and is thought to be a complex disorder related to multiple factors that are similar to other forms of chronic pain syndromes which are complicated further by the biopsychosocial aspects of an illness.1 Although the exact pathophysiology remains unclear, causes can include genetic factors and the presence of pro- and anti-inflammatory cytokines.5
Disease progression including natural history, disease phases or stages, disease trajectory (clinical features and presentation over time)
The stages of disease are commonly classified according to Wilkes, using clinical and radiological data:6
- Clinical: No significant mechanical symptoms other than opening reciprocal clicking; no pain or limitation of motion.
- Radiologic: Slight forward displacement, good anatomic contour of the disc, negative tomograms, no bone structure changes.
- Pathoanatomy: Excellent anatomic form, slight anterior displacement, passive in-coordination demonstrable.
Early intermediate stage
- Clinical: One or more episodes of pain; beginning of mechanical problems consisting of mid-to-late opening loud clicking; transient catching and locking
- Radiologic: Slight forward displacement; beginning disc deformity, slight thickening of posterior edge; negative tomograms, no bone structure changes.
- Pathoanatomy: Anterior disc displacement; early disc deformity; good central articulating area.
- Clinical: Multiple episodes of pain; major mechanical symptoms consisting of locking (intermittent or fully closed); restriction of motion, function difficulties.
- Radiologic: Anterior disc displacement with significant deformity or prolapse of disc (increased thickening of posterior edge), negative tomograms, no bone structure changes.
- Pathoanatomy: Marked anatomic disc deformity with anterior displacement; no hard tissue changes.
Late intermediate stage
- Clinical: Slight increase in severity over intermediate stage.
- Radiologic: Increase in severity over intermediate stage; positive tomograms showing early-to-moderate degenerative changes – flattening of eminence, deformation of condylar head, erosions, sclerosis.
- Pathoanatomy: Increase in severity over intermediate stage; hard tissue degenerative remodeling of both bearing surfaces (osteophytes), multiple adhesions in anterior and posterior recesses; no perforation of disk or attachments.
- Clinical: Characterized by crepitus; variable and episodic pain; chronic restriction of motion and difficulty with function.
- Radiologic: Disc or attachment perforation, filling defects, gross anatomic deformity of disc and hard tissues, positive tomograms with essentially degenerative arthritic changes.
- Pathoanatomy: Degenerative changes of disc and hard tissues; perforation of posterior attachment; multiple adhesions, osteophytes, flattening of condyle and eminence, subcortical cyst formation.
Specific secondary or associated conditions and complications
The natural history of TMD is variable, but the majority of patients have chronic pain or intermittent flare-ups of symptoms.
Essentials of Assessment
Eliciting history should be focused on the pain, such as location, onset, description, etc. as with any other pain complaint including:
- Diffuse jaw pain
- Unilateral pain in muscles of mastication, radiating to temples, side of face or ear
- Clicking at joint
- Limited mouth opening with/without lateral deviation of jaw
- Tinnitus or other ear symptoms
- Nocturnal clenching or bruxism
- Spasticity of muscles of mastication with prolonged chewing
- Recent change in bite
- Psychological stress (resulting in nocturnal teeth grinding)
- Facial trauma
- Long-term/heavy computer use
- Dental work
A past medical and dental history should also be obtained.
Physical exam may reveal asymmetry with smallness of facies on the ipsilateral side. The joint should be palpated with the mouth open and closed to elicit tenderness. Restricted active opening of the jaw can be apparent with joint clicking heard. Passive motion may also be restricted when pulling the jaw forward (fingertips are placed behind the tragi). The masseter, temporalis, lateral pterygoid, digastric, sternomastoid and neck may be painful to palpation when compared to the uninvolved side. Percussion tenderness may be noted for several teeth and tooth wear may be present with clenching and bruxism.
The TMJ is important for functional activities such as chewing, speaking, yawning, kissing, and facial expressions. Careful history should include an assessment on how TMD is impacting quality of life.
Laboratory testing is generally not required for myofascial pain dysfunction and is limited to testing for the presence of systemic arthritic diseases (e.g., rheumatoid arthritis, lupus, etc.), including sedimentation rate, rheumatoid factor, and antinuclear antibody.
The initial imaging recommended to assist in diagnosing TMD is a plain or panoramic radiograph as it can assist with demonstrating an acute fracture, arthritis or disarticulation. Computed tomography (CT) and/or magnetic resonance imaging (MRI) can provide more detailed diagnostic information such as erosion, sclerosis, osteophytes or soft tissue abnormalities.
Supplemental assessment tools
Ultrasonography is a noninvasive and inexpensive diagnostic procedure that can also be used. It can detect, with reasonable accuracy, disc displacement and joint effusions. Nerve blocks or botulinum toxin injections can also be considered as diagnostic and/or treatment.
Early predictions of outcomes
Most patients are considered to improve with comprehensive treatment. However, presence of a jaw function interference, such as clicking or locking, is associated with a poor prognosis.
Behavioral and psychological factors have been shown to play a larger role in TMD than previously thought as it relates to myofascial pain dysfunction and internal derangement. Depression, anxiety and decreased ability to cope with work and family responsibilities must be addressed.
TMD is commonly seen by both medical and dental professionals who need to work collaboratively in the diagnosis and management to contribute to improved outcomes.
Rehabilitation Management and Treatments
Available or current treatment guidelines
Considering there are variable etiological factors, TMD goals of treatment include reducing/eliminating pain and restoring normal jaw function, which for most patients can be accomplished with simple, noninvasive treatment regimes.
At different disease stages
- Heat – A heating pad, hot towel or water bottle to side of face may alleviate muscle spasms.
- Oral Rest – Downgrade diet to mechanically soft for 2 weeks, avoid yawning and laughing with mouth open. Restrict repetitive jaw motions (chewing gum, biting fingernails).
- Medications –
- NSAIDS (Ibuprofen, Naproxen, Indomethacin) for 2 weeks are commonly prescribed.
- Antidepressants are often indicated given the strong association between TMD and psychological factors. Tricyclic antidepressants are most widely used and bedtime dosing can often relieve symptoms in 1 to 2 weeks.7 The effect of other antidepressants has not been well studied.7
- Benzodiazepines are also used and can assist with sleep.7 Use should be limited to 2 weeks due to risk of dependency.
- Narcotic use should be avoided.
- Oral Splinting – An array of interocclusal appliances exist to provide full-arch occlusal stabilization and have been proven to be most effective, up to 70-90% of patients.7 The splints improve the function of the TMJ and the masticatory motor system to reduce abnormal muscle function and protect teeth from attrition and abnormal occlusal loading. As a result, masticatory muscle pain is reduced.
- Behavioral modification – Because of the psychological component in this disorder, decreasing stress is important. Relaxation techniques, conditioning and biofeedback all have been advantageous.7
- Rehabilitation Therapy – Exercise programs are designed to improve muscular coordination, relax tense muscles, and increase range of motion and strength. The most useful techniques for re-education and rehabilitation of the masticatory muscles were found to be manual therapy, muscle stretching and strengthening exercises.8 Electrophysical modalities, such as shortwave diathermy, ultrasound, laser and TENS are used to reduce inflammation, promote muscular relaxation and increase blood flow by altering capillary permeability.
- Acupuncture/Dry needling – Can be an alternate and conservative treatment to management of pain.
- Although limited in studies and consensus, other options to consider are dry needling and injections. Possible injection medications include steroids, autologous blood, botulinum toxin and sodium hyaluronate injections
- Similar treatment options as the new onset/acute stage are utilized.
- Surgical Intervention – If there is internal derangement, ankylosis and/or failed conservative treatment of the TMD, arthroscopy and/or arthrocentesis may decrease pain and clicking and increase ROM. Joint replacement is also an option, but rarely performed secondary to high risk and poor outcomes.
- Total temporomandibular joint (TMJ) reconstruction or implants can also be considered.
Pre-terminal or end of life care
Coordination of care
Given the biophysiological and psychosocial nature of TMD a multidisciplinary approach among dentists, pain/pharmacological management, cognitive behavioral therapy and physical therapy is more likely to achieve an individualized treatment plan for improved success in patient recovery.
Patient & family education
Since stress can cause and/or and worsen TMD, educating patients on stress-reducing techniques could decrease jaw clenching or teeth grinding. Such techniques include deep breathing, progressive muscle relaxation, guided imagery, meditation and/or yoga. Patients should be encouraged to practice daily to relieve symptoms as part of the overall treatment plan. If necessary cognitive behavioral therapy and biofeedback can be recommended. With myogenous etiology of TMJ disorder, symptoms are generally self-limiting, and patients should be reassured that no disease exists. Patients may also require education on the benign nature of muscle spasms.7
Translation into practice: practice “pearls”/performance improvement in practice (PIPs)/changes in clinical practice behaviors and skills
While subjective improvements of the symptoms can be useful, the TMJ’s range of motion is considered the most objective indicator of treatment outcomes. In addition, it is important to understand that proper diagnosis involves exclusion of other potential disease processes such as headaches, migraines, dental infections, otitis media, sinusitis, temporal arteritis, trigeminal neuralgia or a mass.
Cutting Edge/Emerging and Unique Concepts and Practice
Cutting edge concepts and practice
Biologics such as the use of platelet rich plasma (PRP) has been considered as a treatment alternative for TMD. In a comparative study involving 52 patients with refractory TMD, intraarticular PRP injection improved pain intensity, maximal mouth opening and clicking when compared to arthrocentesis.9
Gaps in the Evidence-Based Knowledge
Given TMD consists of multiple contributing disorders, the fragmentation across health professionals and researchers needs to be more coordinated. Focusing on patient-centered care while create more consistent protocols of assessment, management and treatment is in development across several committees and consortiums.
- Slade GD, Bair E, Greenspan JD, et al. Signs and symptoms of first-onset TMD and sociodemographic predictors of its development: the OPPERA prospective cohort study. J Pain. 2013;14(12 Suppl):T20-32 e21-23.
- Bueno CH, Pereira DD, Pattussi MP, Grossi PK, Grossi ML. Gender differences in temporomandibular disorders in adult populational studies: A systematic review and meta-analysis. J Oral Rehabil. 2018;45(9):720-729.
- Slade GD, Bair E, By K, et al. Study methods, recruitment, sociodemographic findings, and demographic representativeness in the OPPERA study. J Pain. 2011;12(11 Suppl):T12-26.
- National Academies of Sciences E, Medicine. Temporomandibular Disorders: Priorities for Research and Care. Washington, DC: The National Academies Press; 2020.
- Palmer J, Durham J. Temporomandibular disorders. BJA Educ. 2021;21(2):44-50.
- Tatli U, Machon V. Internal Derangements of the Temporomandibular Joint: Diagnosis and Management. In: Emes Y, Aybar B, Dergin G, eds. Temporomandibular Joint Pathology – Current Approaches and Understanding.2017.
- Warfield C, Bajwa Z, Wootton R. Principles and Practice of Pain Medicine. 3rd ed. China: McGraw-Hill; 2017.
- Madani AS, Mirmortazavi A. Comparison of three treatment options for painful temporomandibular joint clicking. J Oral Sci. 2011;53(3):349-354.
- Chandra L, Goyal M, Srivastava D. Minimally invasive intraarticular platelet rich plasma injection for refractory temporomandibular joint dysfunction syndrome in comparison to arthrocentesis. J Family Med Prim Care. 2021;10(1):254-258.
Original Version of the Topic
Rosanna Sabini, DO, Dayna McCarthy, DO, Navdeep Jassal, MD. Temporal mandibular joint syndrome. 7/17/2013
Previous Revision(s) of the Topic
Rosanna Sabini, DO, Dayna McCarthy, DO, Navdeep Jassal, MD. Temporal mandibular joint syndrome. 3/27/2017
Rosanna Sabini, DO
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