* Mandibular condyles
* Articular surface of the temporal bone
* Capsule
* Articular disc
* Ligaments
* Lateral pteygoid
Disc displacement is the most common disorder of the TMJ. Disc displacement occurs when the articular disc (which is attached anteriorly to the superior head of the lateral pteygoid muscle and posteriorly to the retrodiscal tissue), moves out from between the condyle and the fossa, such that the mandible and temporal bone contact is made on something other than the articular disc. This results in acute pain known as TMJ pain.
In most instances of disorder, the artiulcar disc is displaced anteriorly upon translation. On opening the mouth, a sound like "pop" or "click" can sometimes be heard, indicating that the condyle is moving back onto the disk, which is known as disc displacement with reduction. On closing the mouth, the condyle slides off the back of the disc, hence another "click" or "pop" sound can be heard or felt, and at this point the condyle is posterior to the disc. Upon clenching of the mouth or jaw, the condyle compresses the bilaminar area, the nerves, the arteries and the veins against the temporal fossa, resulting in acute TMJ pain and inflammation.
In disc displacement without reduction, on opening of the mouth or jaw, the disc stays anterior to the condylar head. Mouth opening is limited and no "pop" or "click" sound is heard upon opening.
TMJ pain is generally due to one of the four common reasons mentioned below:
* The most common cause of TMJ pain is myofascial pain dysfunction syndrome, which primarily involves the muscles of mastication.
* Internal derangement is another cause, and it is defined as an abnormal relationship of the disc to any of the other components of the TMJ. An example of internal derangement is articular disc displacement.
* Osteoarthritis, also known as degenerative joint disease, is another common cause. This involves the organic degeneration of the articular surfaces within the TMJ.
* Temporal arteritis or cranial (skull) arteritis, an inflammatory disease of blood vessels, remains a common cause for TMJ pain.
Other pathologic conditions may affect the TMJ as well, causing pain and swelling too, but this is rare. Examples of such conditions are giant cell tumor, osteosarcoma, aneurysmal bone cyst and chondrosarcoma.
TMJ pain or dysfunction of the temporomandibular joint is commonly known as "TMJ", when actually TMJ is the name of the joint and not the pain in the joint. Temporomandibular joint disorder (or dysfunction) is abbreviated TMD, not TMJ. The term TMD is used to refer to a group of problems involving the TMJs and the muscles, ligaments, blood vessels, tendons, and other tissues associated with them.
Alex Bowmann is the author of this article. For further detail about TMJ and TMJ pain please visit the website.
Processing ...