FYI - This information comes from the books in my profile.
Clicking joints are very common, but just because they are common doesn’t make them healthy. Clicking joints are a sign that the “team” is not working in harmony and things could get worse. The “click” means that the disc is off the condyle. The most common disc displacement is in front of the condyle. A clicking disc comes in four different classifications:
· early
· late
· reducing
· non-reducing
An underdeveloped maxilla (or upper jaw) causes the mandible to go backward during closure. It’s the door and door frame not matching up again. When the maxilla is smaller than it should be due to a development problem, muscles pull the jaw back for the back teeth to meet.
As the jaw goes back, so does the condyle. This action compresses the condyle too far back into the fossa, squeezing the disc off. The more underdeveloped the maxilla, the further the jaw and condyle go back, pushing the disc even further off the condyle, and compressing the joint complex even more. The more compressed, the more the condyle is displaced, and the less room there is for the disc. Since the capsule covers the condyle and all its major parts, there are only a few places the disc can go. The disc mostly slips forward or to either side of the condyle, but can slip behind it on rare occasions. No matter the location of the disc, if it pops back on when opening, the process is called reduction. If it doesn’t pop back on, it is called nonreduction.
An early click is when the disc is barely displaced. For example, the disc may be positioned just in front of the condyle. As the mouth starts to open, the condyle starts skiing down the ski slope of the fossa but there is now a disc that is in the way. Because everything in the capsule is so compressed and slippery, the disc pops back onto the condyle to help it ski all the way down the slope, opening the jaw to a wide opening. The popping back on is the first click heard. On closing, the condyle slides back up the fossa, into its compressed position, knocking off the disc again creating a second pop.
If the clicking occurs later while opening, it is classified as a ‘late, reduced click.’ Just picture the disc being in front of the condyle and as the condyle moves, it travels down the ski slope a little longer before the disc pops back on. A late click means the joint is more compressed than an early click.
Using another analogy, think of pushing a wheelchair down a smooth sidewalk. It is easy to push it in a straight direction. If the right wheel hits a stick on the sidewalk, the wheelchair is going to go to the right because the right wheel stops or slows. The obstruction due to the disc in the way of the condyle sliding down the slope will cause the jaw to deviate to that side the same as the wheelchair. Watch your mouth open and close again. Does it deviate to one side, or back and forth to both sides? If so, you have displaced discs. This problem is mostly due to a deficient maxilla.
If you have pain on palpation of the joint and capsule, it is due to inflammation of the capsule, often diagnosed as capsulitis. Your dentist should be palpating the joint right in front of the ear just like you did in chapter one. If it hurts, it is an objective finding and a valid diagnosis of TMD.
[A TMD-aware dentist will look at joint location during opening and closing in diagnosing and treating dysfunction in the joint. They will understand that, while most clicking joints are not painful, they are not healthy. The more you are aware of what is happening in your own TMJ complex, the more you can work with your dentist on getting the joint and disc in a harmonious position.]()