The temporal mandibular joint (TMJ) is a synovial hinge joint that connects the jaw to the skull. These two joints are located just in front of each ear. Each joint is composed of the condyle of the mandible, an articulating disk, and the articular tubercle of the temporal bone. The movements allowed are side to side, up and down, as well as protrusion and retrusion. This complicated joint, along with its attached muscles, allows the movements needed for speaking, chewing, and making facial expressions.[1]
Pain and functional disturbances related to the TMJ are common, and are collectively termed TMJ syndrome or temporomandibular disorders (TMD).[2, 3] An international group has identified 12 of the most common pain-related and intra-articular TMJ disorders, which include myalgias, myofascial pain, arthralgia, disk displacement disorders, degenerative joint disease, and subluxation (see DDx/Diagnostic Considerations).
Signs and symptoms
Symptoms of TMJ syndrome consist of the following:
Chronic pain in the muscles of mastication described as a dull ache, typically unilateral; pain may radiate to the ear and jaw and is worsened with chewing
Locking of the jaw when attempting to open the mouth
Ear clicking or popping, usually when displacement of the articular disk is present
Headache and/or neck ache
Characteristic findings on physical examination include the following:
Limitation of jaw opening (normal range is at least 40 mm as measured from lower to upper anterior teeth)
Palpable spasm of facial muscles (masseter and internal pterygoid muscles)
Unilateral facial swelling
Clicking or popping in the TMJ
Tenderness to palpation of the TMJ
See Presentation and DDx/Diagnostic Considerations for more detail.
Workup
Along with clinical examination, imaging studies are valuable for identifying causes of TMJ disorders and determining their severity. Imaging techniques used in this setting include the following[4] :
Plain radiography; this includes intraoral x-rays and panoramic (panorex) x-rays (radiographs that provide a full view of the upper and lower jaws, teeth, TMJs, and sinuses)
Computed tomography; cone-beam CT[5] and multidetector CT
MRI
See Workup for more detail.
Treatment
Signs and symptoms of TMJ disorders tend to improve over time with or without treatment for most patients. Initial management of TMJ disorders is with a conservative multimodal approach. A number of therapies are in use, although data supporting their efficacy is often mixed or weak and at best moderate, and reviews and guidelines offer contradictory recommendations on some therapies.[6, 7, 8] More invasive options can be considered when conservative measures have been exhausted.
The pathophysiology of TMJ syndrome is not entirely understood. The etiology is thought to be likely multifactorial, with contributing factors including the following[7] :
Abnormal dental occlusion
Bruxism[8]
Joint capsule inflammation
Muscle spasm
Abnormalities in the intra-articular disk
Pyschological stress, anxiety
Both local insults and systemic disorders may be involved. Local problems frequently arise from articular disc displacement and hereditary conditions affecting the structures of the joint itself, such as hypoplastic mandibular condyles. A study by Tallents et al found TMJ displacement in 84% of patients with symptomatic TMJ versus 33% of asymptomatic subjects.[9]
The TMJs can also be affected by conditions such as rheumatoid arthritis, juvenile idiopathic arthritis,[10] osteoarthritis, and diseases of the articular disks. In addition, hypermobile TMJs, nocturnal jaw clenching, nocturnal bruxism, jaw clenching due to psychosocial stresses, and local trauma also play a significant role.
A study of 299 females aged 18-60 years suggests that compared with nonsmokers, female smokers younger than 30 years had a higher risk of temporomandibular disorder than older adults.[11]
As described by Hegde, a strong understanding of how the trigeminal nerve innervates the TMJ and surrounding structures explains the pain and referred pain patterns of TMJ disorders.[12] Irritation of the mandibular branch (V3) of the trigeminal nerve results in pain locally at the TMJ and also to other areas of V3 sensory innervation, which include the ipsilateral skin, teeth, side of the head, and scalp.
Currently, an estimated 10 million people have TMJ disorders, and roughly 25% of the population have symptoms at some point in their lives.
Mortality/Morbidity
The morbidity of the disorder is related to significant pain on movement of the jaw. While some patients' symptoms may resolve within weeks, others may have chronic symptoms that persist even with extensive therapy.
One study by Rammelsberg et al followed 235 patients over 5 years.[13] In this study, roughly one third of patients had complete resolution of pain, one third had continuous pain over the 5 years, and one third had recurrent episodes with periods of remission.
Race-, Sex-, and Age-related Demographics
See the list below:
No apparent association with race exists.
Female-to-male ratio is roughly 4:1.
Highest incidence of TMJ syndrome is in adults aged 20-40 years
TMJ syndrome is found infrequently in the pediatric population
Characteristic findings on physical examination include the following:
Limitation of jaw opening (normal range is at least 35 to 40 mm as measured from lower to upper anterior teeth; usually less than 25 to 30 mm in TMJ syndrome
Palpable spasm of facial muscles (masseter and internal pterygoid muscles)
Unilateral facial swelling
Clicking or popping in the TMJ (press into TMJ and have patient open and close the jaw)
Tenderness to palpation of the TMJ via the external auditory meatus (the tips of the fingers placed behind the tragi at each external acoustic meatus and pulled forward while the patient opens the jaw)
When temporomandibular joint (TMJ) syndrome is suspected, the following histories should be obtained:
Aggravating and relieving factors, with a focus on eating or chewing
Historical otologic and audiologic abnormalities
Historical sinus disease
History of inflammatory arthritis
Repetitive habits such as nail biting, gum chewing, or other potentially pathologic behaviors
Bruxism, grinding, or clenching of teeth
Other chronic pain syndromes
Oftentimes if one of the above aggravating factors is identified, treating the underlying cause or modifying the underlying behavior may improve symptoms sufficiently that additional workup may not be needed.
No laboratory studies are specifically indicated to rule in temporomandibular joint (TMJ) syndrome; however, appropriate laboratory samples may be drawn to help rule out other disorders if an underlying cause is not readily apparent:
Complete blood count (CBC), if infection is suspected
Calcium, phosphate, or alkaline phosphatase, for possible bone disease
Uric acid if gout is suspected
Serum creatine and creatine phosphokinase, indicators of muscle disease
Erythrocyte sedimentation rate if temporal arteritis is suspected
Rheumatoid factor if rheumatoid arthritis is suspected.
Along with clinical examination, imaging studies are valuable for identifying causes of TMJ disorders and determining their severity (see DDx/Diagnostic Considerations). Imaging techniques used in this setting include the following:
Plain radiography; this includes intraoral x-rays and panoramic (panorex) x-rays (radiographs that provide a full view of the upper and lower jaws, teeth, TMJs, and sinuses)[15]
Computed tomography (CT); this includes cone-beam CT (CBCT), which dental professionals use to create three-dimensional images,[5] and multidetector CT (MDCT)
Magnetic resonance imaging (MRI)
The American Academy of Oral and Maxillofacial Radiology (AAOMR) and the American Academy of Orofacial Pain (AAOP) have published a position statement on TMJ imaging.[4] Recommendations are as follows:
In patients with suspected TMJ arthritis, CT imaging, preferably CBCT, should be used to evaluate osseous changes.
In patients with suspected odontogenic pain, intraoral or panoramic radiographs should be used.
In patients with complex odontogenic disorders, a limited field of view CBCT scan may be required.
In patients with a suspected developmental disorder of the TMJ (eg, aplasia, hypoplasia, hyperplasia), panoramic radiography should be used for the initial radiologic assessment, and CBCT imaging should be acquired for the pre- and postoperative analysis of the TMJ complex.
In patients with suspected disk displacement, proton density or T1-weighted MRI of the TMJ, in the closed- and open-mouth positions, should be used. When joint space effusion is suspected, T2-weighted MRI should be used.
In patients with trauma limited to the mandible, panoramic radiography can be used as the initial imaging study. In patients with known or suspected fractures of the mandibular condyle, CBCT imaging with three-dimensional reconstruction should be used
In patients with known or suspected cysts and benign tumors in TMJ regions, CT imaging should be used.
In patients with known or suspected malignant tumors in TMJ regions, CT imaging/MRI should be used.
MRI for evaluation of TMJ disk displacement or pathology often involves central sagittal scans alone. However, Litko-Rola et al found that multisection evaluation with both sagittal and coronal scans had significantly higher sensitivity for evaluation of TMJ internal derangement. In their study of 382 TMJs in 191 patients with disk displacement, normal disk position was identified in 148 TMJs (38.7%) on central oblique sagittal scans, compared with 89 TMJs (23.3%) on all oblique sagittal and coronal scans (P< 0.001).[16]
The auriculotemporal branch of the trigeminal nerve provides the sensory innervation of the TMJ. A diagnostic nerve block of the auriculotemporal nerve can be helpful in differentiating whether unilateral orofacial pain originates in the TMJ capsule.[17]
To perform a diagnostic anesthesia block, use a 25- to 30-gauge needle and inject 0.5 mL of short-acting anesthetic about 0.5 inches below the skin just inferior and lateral to the mandibular condyle. If the patient does not experience pain relief with the nerve block, consider other causes of the orofacial pain.
In most patients, the signs and symptoms of temporomandibular joint (TMJ) disorders improve over time with or without treatment. As many as 50% of patients have symptomatic improvement in 1 year and 85% in 3 years.[7]
Initial management of TMJ disorders is with a conservative multimodal approach.[6] A number of therapies are in use, although data supporting their efficacy is often mixed or weak and at best moderate, and reviews and guidelines offer contradictory recommendations on some therapies.[6, 7, 8] More-invasive options can be considered when conservative measures have been exhausted.
Conservative treatment of TMJ syndrome may include the following[7, 18, 19] :
Education and self-care; for example, patients should eat a soft diet, and avoid counterproductive habits such as excessive gum chewing or nail biting. Warm and cold compresses should be used at night along with gentle massage of the TMJ area. Patients should avoid jaw clenching and teeth grinding if possible.
Pharmacologic therapy (see below)
Physical therapy.[20]
Dental splints or mouthguards may reduce pain by keeping the jaw more properly aligned and limiting nocturnal bruxism and teeth grinding.[19] However, some reviews suggest they may not provide benefit.[6, 18, 21, 22]
Some patients find benefit from ultrasonic therapy. This provides deep heat to the area of tenderness and also has non-thermal effects. Transcutaneous electrical nerve stimulation (TENS) has also been used to reduce pain.[7, 23]
Low-intensity laser therapy has been shown to reduce pain in TMJ syndrome.[24, 25, 26]
Dry needling of trigger points.[27]
Acupuncture.[28]
In view of the role that psychological factors play in TMJ syndrome, measures such as cognitive-behavioral therapy and bio-behavioral approach may be beneficial.
Pharmacologic therapy
Pharmacologic therapy for acute and chronic TMJ-related pain includes acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs).[29] Topical NSAIDs such as diclofenac can be used to minimize risk of adverse effects seen more commonly with oral formulations. For muscular spasms and teeth-clenching, agents such as muscle relaxers or even benzodiazepines may be used. Tricyclic antidepressants (TCAs) are second-line options for pain and teeth grinding. Note that selective serotonin uptake inhibitors (SSRIs) may induce bruxism.[7]
Injections
If conservative therapies fail, or for severe acute exacerbations, intra-articular injection of local anesthetics or steroids may be used for TMJ syndrome. However, repeated intra-articular injections are not recommended.
Intramuscular injection of onabotulinumtoxinA (BTX-A) has been advocated for management of myofascial pain. A systematic review of BTX-A injections for myofascial pain related to TMJ disorders found that it was significantly effective in reducing the intensity of pain, although a few studies have reported that BTX-A and saline placebo injections had statistically equivalent ability to decrease pain and improve jaw function.[30, 31]
TMJ syndrome in juvenile idiopathic arthritis
A guideline from the American College of Rheumatology includes recommendations for the treatment of active TMJ arthritis in patients with juvenile idiopathic arthritis.[32] All but one of the recommendations are conditional, and all involve very low certainty of evidence. The recommendations are as follows:
Consider a trial of scheduled NSAIDs as part of initial therapy
Consider intra-articular glucocorticoids as part of initial therapy
Do not use oral glucocorticoids as part of initial therapy
Conventional synthetic disease-modifying antirheumatic drugs (DMARDs) are recommended for patients with an inadequate response to or intolerance of NSAIDs and/or intra-articular glucocorticoids (this is the only strong recommendation)
Consider biologic DMARDs for patients with an inadequate response to or intolerance of NSAIDs and/or intra-articular glucocorticoids and at least one conventional synthetic DMARD
Inflammatory arthritis due to conditions such as rheumatoid arthritis may rarely affect the TMJ, often in a bilateral manner, given the predilection for diseases such as rheumatoid arthritis to affect joints in a fairly symmetric pattern. Timely disease control is of vital importance when TMJ pain is thought to be due to inflammatory arthritis, as the feared result of undertreating is permanent damage to the joint, often leading to a secondary osteoarthritis of the joint, which portends a much more chronic refractory disease process.
If conservative treatments fail, operative repair may be considered.[33] Operative repair can range from arthroscopic procedures, which can wash out the joint and allow for small repairs,[34] to open procedures. Open procedures can utilize jaw implants, synthetic articular disks, or total TMJ replacement with custom-made alloplastic prostheses.[35] With TMJ ankylosis associated with juvenile idiopathic arthritis, reconstruction with a costochondral graft is the gold standard.[36]
However, in a long-term study by Fricton et al, synthetic implants did not lead to an improved outcome compared with nonimplant surgical repair or nonsurgical rehabilitation.[37] This was determined by looking at subjective and objective measures of symptom severity and functional deficits.
Handa et al reported on a complication of TMJ surgery termed first bite syndrome, in which pain (most often in the parotid region) is triggered by a taste stimulus and subsides with subsequent bites of food. In 19 patients who had undergone TMJ surgery, the median duration of onset was 2.75 months postoperatively. The syndrome resolved spontaneously in two patients and resolved completely with onabotulinum toxin A injections in one patient.[38]
Offer routine follow-up care with an ear, nose, and throat (ENT) specialist, dentist, or an oral maxillofacial surgeon (OMFS). If intractable pain and/or dislocation are present, more urgent consultation may be necessary.
Nonsteroidal anti-inflammatory drugs (NSAIDs) and tricyclic antidepressants (TCAs) are the mainstays of pharmacologic treatment for temporomandibular joint (TMJ) syndrome. Patients with protracted pain syndromes eventually may require muscle relaxants or intra-articular corticosteroid injections. In refractory cases, benzodiazepines or opiates may be considered but should be avoided if possible.
NSAIDs are most commonly used for relief of mild to moderate pain, with use most often limited by pre-existing cardiovascular, renal, or gastrointenstinal morbidity, or concern for such morbidity. To reduce risk of adverse effects, generally the optimal approach is to use the lowest effective dose for the shortest duration possible. If more long-term use is required, the prescriber should monitor cardiovascular, renal, and gastrointestinal systems for signs of adverse effects.
Clinical Context:
Use with extreme caution, given the risk of central nervous system (CNS) depression, especially in elderly patients and those already on other CNS-depressing medications.
What is temporomandibular joint (TMJ) syndrome?What causes pain in TMJ syndrome?What is the pathophysiology of TMJ syndrome?How prevalent is TMJ syndrome?What is the morbidity of TMJ syndrome?What are the demographics of TMJ syndrome?What are the symptoms of TMJ syndrome?What are the characteristic findings on physical exam in TMJ syndrome?What are the differential diagnoses for Temporomandibular Joint (TMJ) Syndrome?Which lab studies are indicated in the workup of TMJ syndrome?Which imaging studies are indicated in the workup of TMJ syndrome?What is the role of a diagnostic nerve block in the workup of TMJ syndrome?What is the initial treatment of TMJ syndrome?Which specialist consultations are indicated in the treatment of TMJ syndrome?Which medications are used in the treatment of TMJ syndrome?Which medications in the drug class Skeletal Muscle Relaxants are used in the treatment of Temporomandibular Joint (TMJ) Syndrome?Which medications in the drug class Nonsteroidal anti-inflammatory drugs (NSAIDs) are used in the treatment of Temporomandibular Joint (TMJ) Syndrome?
Evan Dombrosky, MD, Rheumatologist, Central Virginia VA Health System
Disclosure: Nothing to disclose.
Specialty Editors
Francisco Talavera, PharmD, PhD, Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference
Disclosure: Received salary from Medscape for employment. for: Medscape.
Gino A Farina, MD, FACEP, FAAEM, Professor of Emergency Medicine, Hofstra North Shore-LIJ School of Medicine at Hofstra University; Program Director, Department of Emergency Medicine, Long Island Jewish Medical Center
Disclosure: Nothing to disclose.
Chief Editor
Herbert S Diamond, MD, Visiting Professor of Medicine, Division of Rheumatology, State University of New York Downstate Medical Center; Chairman Emeritus, Department of Internal Medicine, Western Pennsylvania Hospital
Disclosure: Nothing to disclose.
Additional Contributors
Richard H Sinert, DO, Professor of Emergency Medicine, Clinical Assistant Professor of Medicine, Research Director, State University of New York College of Medicine; Consulting Staff, Vice-Chair in Charge of Research, Department of Emergency Medicine, Kings County Hospital Center
Disclosure: Nothing to disclose.
Steven M Heffer, MD, Consulting Staff, Department of Emergency Medicine, Greenwich Hospital
Disclosure: Nothing to disclose.
Vivian Tsai, MD, MPH, FACEP, Assistant Professor of Emergency Medicine, Mount Sinai School of Medicine, Queens Hospital Center
Disclosure: Nothing to disclose.
Acknowledgements
Jerome FX Naradzay, MD, FACEP Medical Director, Consulting Staff, Department of Emergency Medicine, Maria Parham Hospital; Medical Examiner, Vance County, North Carolina
Jerome FX Naradzay, MD, FACEP is a member of the following medical societies: American Academy of Emergency Medicine, American College of Emergency Physicians, and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.
Joshua Parnes, MD Resident Physician, Department of Emergency Medicine, Kings County Hospital Center
Dental Cone-beam Computed Tomography. U.S. Food & Drug Administration. Available at https://www.fda.gov/radiation-emitting-products/medical-x-ray-imaging/dental-cone-beam-computed-tomography. September 28, 2020; Accessed: March 18, 2024.
Surgical Management of TMJ Disorders. American Society of Temporomandibular Joint Surgeons. Available at https://astmjs.org/surgical-management-of-tmj-disorders-2/. Accessed: March 19, 2024.