Temporomandibular Joint (TMJ) Syndrome Workup

Updated: Jun 02, 2020
  • Author: Vivian Tsai, MD, MPH, FACEP; Chief Editor: Herbert S Diamond, MD  more...
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Laboratory Studies

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, as follows:

  • 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

Imaging Studies

Imaging studies generally are not indicated in the emergency department, unless a fracture is suspected. Considerations are as follows:

  • Panorex may show a fracture, evidence of osteoarthritis, or displacement of the articular disk; Ahn et al demonstrated that Panorex films can also be effective in evaluating patients with internal derangement of the TMJ [9]

  • Plain radiographs may demonstrate resting and hinge movement of the TMJ

  • CT scan may reveal greater detail of bones than radiographs alone

  • MRI is the test of choice when looking for disk displacement or pathology

For more information, see Imaging of Meniscus Abnormalities in the Temporomandibular Joint.


Diagnostic Nerve Block

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 the unilateral orofacial pain originates in the TMJ capsule. [10]

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.