The Jaw

The jaw, otherwise known as the temporomandibular joint, is a unique structure in the body. No other joint in the body sits like the jaw does. It essentially hangs in place and is secured by several muscles and tendons. It also has a disc, like our spine does, to shock absorb and support the joint as it rolls around when we open our mouth, chew, and talk. The jaw is also highly proprioceptive, which means it has many fibres in and around the joint that send messages to the brain, telling it where the joint is and what it is doing.

There are several common stressors to the joint, including:

• Clenching and grinding of the teeth

• Shallow, open-mouth breathing

• Biting and chewing objects

• Emotional stress

• Forward head posture
  

Forward head posture of the neck is the number one factor that distorts and causes problems in the jaw. It is very common that unless you’ve had direct trauma to the jaw, such as falling and landing on it, the jaw is not the primary problem. The underlying cause of jaw pain is often coming from elsewhere.

A typical posture of looking down at your phone carries the head too far forward out of the midline, and the added effect of gravity places a lot of pressure on the jaw and neck. Your head weighs about 10–12 pounds (4.5–5.5 kg) in a neutral position. But as you tilt it forward, the force on your cervical spine increases by up to 60lbs. That is the weight of a small child! This tightens the sternocleidomastoid muscle at the front of the neck. Typically, we also mouth-breathe in this position. The neck is in extension and the jaw retracts. This causes muscle and tendon tension in the jaw and can lead to pain, poor movement, and sometimes jaw locking.

Our approach in chiropractic care is to look for the primary cause rather than just soothing the symptoms. The upper cervical spine, neck posture, range of motion, and joint restrictions are the first areas to examine and investigate when considering a jaw problem.

(Picture thanks to Alexander Krivitskiy)