In dentistry, Canine Rise is a well known concept. But it’s highly misunderstood.
Canines, or some people call them “eye teeth”, are very important in occlusion (the way teeth come together). Canine rise is the phrase used to describe the lateral slide where the canines guide the side to side movement of the mandible.
The canines on the side we are sliding to are sliding against each other as we chew our food or slide our jaw to one side or the other. This is a protective mechanism and acts to protect the other teeth from wear and fractures, as well as the muscles of mastication. I will explain that one in a minute.
If you consider what that looks like from the side, if we imagine the jaw sliding to the right, the right side canines are guiding this slide. As the jaw slides back to the side and back, the back teeth disclude, and slide out of contact with each other.
Why is this important?
One reason is to simply protect the posterior teeth from wear or fractures. Canines are designed for this so they are meant to guide and allow the posterior teeth to separate on lateral mandible movements.
The second reason is that posterior disclusion results in a reduction in muscle activity of the muscles of mastication. As the mandible slides to the side, and the canines provide posterior separation, and that shuts off the activity in the masseter and the temporalis. That results in muscle relaxation.
But not in all people. But we will get to that in a bit.
If canine guidance is lost or not present, and the posterior teeth hit on lateral slides, this typically causes muscle tension or pain. But it can lead to Temporo-Mandibular Joint Disorder (TMD) as well, and result in jaw pain and other TMD related symptoms.
So what about those where the muscle activity is not reduced even with canine rise? Bruxers.
To learn more about bruxism, check out our other (blogs/videos) on this topic.