You may have noticed that when eating or opening your mouth wide that your jaw clicks. The clicking may be intermittent, constant on one side or sometimes both. Clicking noises in the jaw can be disconcerting and often leave people wondering if there is a problem which they need to address. The good news is that clicking of the jaw is quite common and often not a big deal. There are times however, where the clicking can be problematic and needs to be addressed.
So, how do you know if your clicky jaw is a problem? As a rule, the louder the click and the more commonly it occurs, the more likely that it is an issue that may need to be addressed. Certainly, clicking with associated pain or discomfort should be assessed by a physiotherapist trained in treatment of jaw injuries.
So exactly what is the clicking and why does it happen? To understand this, we first need a quick lesson in the anatomy of the jaw or temporomandibular joint TMJ. The TMJ is made up of two bones, the lower jaw bone or mandible, and the upper temporal bone, which forms part of the skull. Between these two bones lies a cartilage disc. The cartilage dis is attached to the lateral pterygoid muscle at the front and a band of elastic tissue at the back.
In a normally functioning jaw, the disc sits neatly between the two bones of the TMJ. When you open the mouth, the lower bone (mandible) rotates in the joint and glides forward as shown below. As the lower bone glides forward, muscles attaching to the front of the disc, pull it forward to keep it between the two bones to cushion the movement of one bone on the other. As we close the mouth, the muscles which have pulled the disc forward relax and the posterior elastic tissue pulls the disc back into its resting position.
For several reasons, the muscles which pull the disc forward can become shortened, pulling the disc forward of its normal position. The most common of these is through clenching and grinding of the teeth. The muscles which operate the jaw are designed to work only for very short periods of time and when we clench and grind, we are often making them work for hours at a time. In this case they get very fatigued and tight. Now when we open the jaw, as the lower bone, the mandible moves forward, the disc slips back on top of the mandible resulting in an audible click. This click can be painful or symptom free. As we close the mouth, the disc slips back into its forward position in relation to the joint.
When the disc has been forward positioned for a long period of time, the elastic tissue in the back of the joint may become stretched and loose some of its elastic recoil and thus decrease its ability to passively pull the disc back into the correct position.
Depending on the degree of change to the joint mechanics and the amount of overload of the muscles and tissues around the joint, it may become uncomfortable or even painful to open the mouth wide and to chew. In these cases, there are several techniques that can be used to relax the muscles of the jaw, attempt to restore normal joint mechanics and to decrease symptoms. These can include massage, stretch, acupuncture and joint mobilisations. Importantly, as the problem is often driven by stress related clenching and grinding of the teeth, advice on stress management techniques and some ongoing self-treatment techniques to manage the build up of tension in the tissues is an important part of management.
So if you are worried about your clicky jaw or are having pain associated with a clicky jaw, come in and see one of our experienced physios for an assessment and advice on the best course of management.
Article by Jim Burke
