A technical understanding of TMD / TMJ

TMD X-Ray and Tomography

Temporomandibular joint tomographic x-rays play a valuable role in diagnosis and treatment. Recent studies have concluded that a fairly high rate of unexpected new osseous and positional findings support the need for tomograms in patients with a clinical diagnosis of derangement or joint pathology. Approximately forty to fifty percent of tomographic radiographic examinations produced a change in diagnosis.

Tomography is medically necessary to evaluate bony changes in the condyle and temporal bone such as flattening, erosion, and sclerosis. Condylar position and asymmetries of mandibular anatomy can be most clearly evaluated with the exacting multiple slice technology of tomography. Additionally, the ability to screen for additional abnormalities such as tumors or cysts is provided by tomographic radiography.


Efficacy of TMJ radiographs in terms of expected versus actual findings, UCLA, Oral Surgery, Oral Medicine, Oral Pathology 1995;79:367-81

Care for Temporomandibular Disorder Cervical and Facial Myositis and Cephalgia

Treatment consisted of maxillary and mandibular orthopedic repositioning appliances to recapture the displaced discs. The maxillary appliance serves as a stabilizer for sleeping and reclining to offset gravitational forces. This appliance is very bulky in the anterior area and would greatly impede mastication and speaking. The mandibular appliance was fabricated and is intended for daytime use and can be used for mastication and usual daily activities.

TMD Trauma

A study in the Journal of Oral Rehabilitation in 1996 titled “Trauma in Patients with Temporomandibular Disorders: frequency and treatment outcome” was to assess the incidence of jaw injury in TMD patients and to compare the severity of the symptoms, the clinical characteristics and the treatment outcome in TMD patients with or without a history of trauma to the head and neck region directly linked to the onset of symptoms. The study sample included 400 consecutive TMD clinical patients. In 24.5% of patients the onset of the pain and dysfunction could be linked directly to the trauma, mainly whiplash accidents.

No significant differences could be found between the two groups in daily recurrent headache, dizziness, neck pain, joint crepitation and pain in the joints. Maximal mouth opening was less than 2-0 mm in 14.3% of patient with a history of trauma and in 4.1% of those without such a history. According to the Helkimo dysfunction index (DI), more trauma than non-trauma TMD patients belonged to the severe dysfunction groups (DI 4 and 5) at first examination.

The outcome of a conservative treatment procedure (counseling, occlusal splint, physiotherapy, occasionally occlusal therapy and non-steroidal antiinflammation drugs was not different between the two groups at the 1 year evaluation. The degree of maximal opening was similar: less than 20 mm in 3.7% and 2.2% in trauma and non-trauma patients respectively.

Forty percent and 41% respectively were symptom free or had DU = 1. The results suggest that external trauma to the joint or to the jaw in general is an important initiating factor in the etiology of TMD and also that the prognosis is favorable.

Treating for a Temporomandibular Disorder and Cephalgia

The necessity for range of motion movements is as follows:

Taking range of motion movements is an accepted test for diagnosis and treatment of temporomandibular disorders. The measurements are a tool to evaluate progress and assist in treatment decisions. Normal range of motion for mandibular opening is approximately 50 mm with 12 mm being the norm for right and left lateral excursions. A reduced opening with difficult excursion may indicate a severe trismus or a closed lock of the temporomandibular joint. An opening much above the norm may indicate hypermobility and stretched ligaments in the jaw joint.

A Clinical Outline of Temporomandibular Joint Diagnosis and Treatment, by Dr. William B. Farrar and Dr. William L. McCarty examines in detail the necessity for various range of motion measurements and is suggested reading.

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