Tumors, Osteonecrosis and Systemic Arthritis

TMJ Synovitis

Pain in the TMJ is usually described as a sharp shooting, burning or aching pain in front of the ear. The pain comes when the nerve structures become compressed or irritated and/or the jaw structures become damaged causing the release of pain chemicals into the surrounding joint fluid (synovium). 

This usually happens when either the joint has too much pressure put on it (i.e. trauma or clenching), or when the disks dislocate from their proper position causing the pain sensitive tissues to be compressed and irritated. Additionally, the adverse loading can lead to the formation of free radicals causing further reduction in the joint fluid and destruction of the cartilage.

Diagram 1 – TMJ Adhesions

Anchored Disc Phenomenon

This occurs when there is a severe loading of the TMJ which pushes the synovial fluid out of the superior joint space causing the disk to stick to the superior surface of the joint fossa. On MRI the disk will appear in normal position however there will be significant limitation in mouth opening. This is typically treated effectively with a minimally invasive arthroscopy.

TMJ Adhesions

Adhesions can also form between the disk and the cartilage and bone above and below the disk. These are like small areas of scar tissue that keep the disk from moving freely. These are often associated with long standing disk displacements or trauma. This is typically treated effectively with a lysis and lavage procedure or progressive manual manipulations.

TMJ Osteonecrosis

When the blood flow to the joint is compromised, as can happen with trauma, part of the jawbone can die. This can lead to severe degenerative changes within the TMJ and bite shifting. The use of Bisphosphonates for osteoporosis may increase the incidence of this.

Systemic Inflammatory TMJ Arthritis

About 20% of patients with Rheumatoid arthritis will develop changes within the TMJ although the TMJ is typically not one of the first joints affected. This can lead to pain, swelling, bite shifting and limited mouth opening. Other inflammatory conditions such as in Lyme’s or psoriatic arthritis can also affect the TMJ.

TMJ Tumor

Tumors are not common within the TMJ but Dr. Pehling has seen several cases of osteochondroma. Additionally we have found tumors within the auditory nerve (acoustic neuroma) and within the neck which have referred pain into the jaw. Breast cancer has been observed to metastasize into the TMJ as well.

Jaw Muscle Disorders

The jaw muscles run along the temples of your head, the sides of your face and down the front of your neck. That is why it is common to have headaches along the side of your head, neck pain, and facial pain with TMJ disorders. Jaw muscle pain usually occurs because either there is joint dysfunction leading to protective splinting of the jaw muscles or through excessive contraction (clenching or grinding). 

Sudden onset jaw muscle pain usually occurs because of joint dysfunction. If you slip a disk in your back, the muscles in the area will tighten up to brace you from using that area, the jaw works the same way. The most common jaw muscle disorders are Myofascial pain and Muscle spasm. The jaw muscles are some of the strongest muscles within the body capable of exerting around 300lbs of pressure on the first molars.