The misconceptions about verifying and and using centric relation (CR) are unfortunately all too common for new and even experienced dentists. The myths that are often associated with CR, ultimately prevent patients from receiving optimal care.
Allow me to ask you these four questions
- When you graduated from dental school, did you have a complete understanding of the importance of centric relation?
- Had you been taught how to find and verify centric relation?
- Were you taught to mount casts in centric relation with a face-bow when doing crown and bridge or other prosthodontics procedures?
- Did you have a working knowledge of occlusion and the required skills to perform occlusal equilibration?
These are questions which we ask dentists who attend the curriculum at The Dawson Academy. Our routine experience is that almost no one in the audience can answer “yes” to any of the above questions… much less all four of them.
There's only one explanation for not routinely using centric relation as a key requirement for proper diagnosis and treatment of sore teeth, cracked cusps, excessive wear problems, many aspects of orofacial pain, and as a standard essential for practicing dentistry with predictability. The explanation for not paying attention to CR has to be that the concept and the importance of centric relation is simply not understood… or worse, is misunderstood. So let's look at just a couple of the reasons for confusion about this critical essential for predictive dentistry.
Myth number one... Patients don't use centric relation.
You have very likely been told, “Do all your dentistry at MIP” (maximal intercuspal position). This is the most common fallacy and the reason for so many problems of discomfort and unsatisfactory treatment. Centric relation is the physiologic end-point for the jaw joints during closure if there are no occlusal interferences to complete seating of the joints. If there are deflective occlusal interferences that require displacement of the joints to achieve MIP, the result is hyperactivity and incoordination of the masticatory musculature. This often results in what we call occluso-muscle pain. Also, It is these interferences to CR that result in excessive wear, hypermobility of teeth and many fractured cusps and restorations. It is the number one cause of sore teeth.
The confusion often comes from the fact that some patients have occlusal interferences to centric relation but do not seem to have any observable problems. Dentists must observe the dentition for signs of instability before assuming that major changes are necessary. What I have observed in hundreds of patients in practice is that such signs of instability have been ignored by my patients’ previous dentists. The most telling sign is excessive wear that is always an indication of occlusal disharmony between the teeth and the TMJs.
For dentists who have learned the finer points of finding and verifying centric relation, they can observe signs of instability in the dentition. This becomes a commonplace observation and very frequently allows the dentist to prevent further destruction of the dentition.
Myth number two… A little displacement from CR is OK.
A little-known but very important fact that every dentist should be aware of is that teeth are actually exquisitely sensitive sensors that program the masticatory system neuromuscular activity. Even the most minute interference to complete seating of the TMJs can activate occluso-muscle symptoms that can include sore and sensitive teeth as well as mild to severe muscle pain. This fact brings us to the next source of confusion. That is a failure to completely and firmly seat both condyle-disc assemblies at the uppermost position in their respective fossa when analyzing an occlusion or taking a bite record.
Myth number three… Just allow the jaw to close when taking a bite with no help from the dentist.
This sounds logical but it will rarely get you the kind of predictability you can achieve with a precise recording of centric relation. The reason we use load testing is to verify that the condyles are fully seated and not being held down the eminence by the lateral pterygoid muscles. It also is a clinical procedure to help rule out structural intracapsular disorders. For the kind of predictability that makes dentistry a joy, you want to be certain that when you alter an occlusion you are bringing it into perfect harmony with completely seated , stable, healthy TMJs. If you don't have that kind of assurance, it won't matter whether you are doing a simple filling or a complete mouth reconstruction. You will be rolling the dice on your patient’s complete satisfaction with whatever treatment you are rendering. There's no need to leave the results of your dentistry up to that kind of chance.
If you are not 100% confident in your ability to solve your patients’ occlusal wear problems or discomfort within the masticatory system, learning how to diagnose and treat with predictability will be life-changing. I urge you to give it top priority. Learn the foundation of predictably creating a stable occlusion in Functional Occlusion - From TMJ to Smile Design. Learn more here