How a Missed Centric Causes Problems
Posted by: Dr. Peter Dawson
By Dr. Peter E. Dawson
Centric relation is the single most important concept that must be understood by every dentist who works on teeth. Unfortunately, there is too much misinformation mixed with a total lack of information regarding why centric relation is so important. Even when centric relation is understood, there is still the essential step of learning how to find it and verify that you got it perfectly. I say perfectly, because even the slightest error in locating this specific condylar relationship can negate the value of a perfected occlusion.
Let's start with an understanding that learning to take a perfect centric relation recording is a very achievable goal. Through the Dawson Academy, thousands of dentists have learned to record centric relation to needlepoint accuracy. And they can prove this accuracy through the use of needlepoint recordings on an instrument called a centri- check. (The instrument used in all our hands-on classes for verification)
The reason centric relation is so important is because it is the highest possible position of the condyle- disc assemblies that is achieved by coordinated muscle activity when the jaw is closed. At this uppermost position, the jaw joints are seated firmly against a bony stop so they cannot go higher. The goal is to coordinate this uppermost condylar position at the most closed jaw relationship with contact of the anterior teeth. This provides a stopping point for both the back end of the mandible and the front end of the mandible. The goal then, is to make sure that the posterior teeth do not interfere with either the condyles in the back or the anterior teeth contact in the front. This is the goal of a perfected occlusion. When it is achieved, it virtually guarantees a comfortable jaw relationship with a peaceful neuromusculature.
When centric relation is missed, it is always missed downwardly because centric relation is at an apex of force, superiorly placed in the fossa. The walls of the fossa do not permit the condyle disc assembly to move in any direction from CR without moving downwardly. So if teeth are harmonized to a missed centric, they will always interfere when the condyles are seated, as they will be during coordinated muscle closure. The net result is overload of the posterior teeth that interfere as each condyle is seated upwardly. This is the major cause of excessive wear, tooth hypermobility, sore teeth, painful muscles, fractured restorations, and discomfort.
Dentists who learn the rules for a harmonious, comfortable occlusion are light years ahead of "usual and customary dentistry". It is the first essential in becoming a "go to" dentist in your town.