What is TMJ?
TMJ stands for temporomandibular joint. This is the joint connecting the upper and lower teeth that allows the jaw to open, close, move backward and forward, and from side to side and chew food.
The term “TMJ Syndrome” refers to a series of symptoms that result from incorrect positioning and dysfunction of the jaw joints and associated structures and muscles. It has a number of causes, notably if your bite becomes misaligned, or you grind your teeth, or you have an accident.
This condition can result in muscle over-contraction, spasms and trigger points, which are a factor in approximately 80% of all tension-related headaches.
In addition, internal disc problems and arthritis in the TMJs can cause clicking and locking of the joints, inability to open the mouth fully and acute localized pain in the jaw joint area.
The jaw joint sits just in front of the ear, so if there is backwards compression of the joint you may get ear symptoms as well, such as tinnitus, earache or a feeling of fullness and blockage in the ear.
Let’s take a closer look at our physiology to understand what is actually happening.
Only the lower jaw (mandible) is able to move; the upper jaw (maxilla) is part of the skull.
The teeth determine the end positioning of the mandible, and position of the jaw joints in relation to the skull. However, the teeth close only in respect to where they fit together the best, which may or may not be where the muscles and ligaments that suspend and move the jaw, want to be.
The joints and muscles will therefore assume whatever position is dictated by the teeth.
Muscles are composed of bundles of muscle fibers, and these fibers have a certain resting length at which they operate the best – their “physiological rest position”. At this position, the muscle is in its most relaxed and strongest position.
If the muscle is elongated or foreshortened, instead of at its relaxed resting length, the muscle fibers will be tensed. This tense contraction impedes blood circulation, resulting in spasm and cramping of the muscle tissue and many of the symptoms of TMJ dysfunction.