In previous articles, I covered the topic of doing a functional analysis on mounted models and it's importance. Although it was discussed how to mount the models in centric relation, one question still remains: If we choose to now restore our patients in centric relation, how do we then get the information from our centric relation mounted models back to the patient?

The good news is that we have more than one option when deciding how to restore the patient in centric relation. While no option is considered better than another, some options might allow us to be a bit more efficient with our time.

Option 1: Equilibrate the patient in CR prior to any restorative treatment. This option is essentially the easiest because once CR is equal to intercuspal position (ICP) it allows us to treat the patient like every other patient. Meaning, before we do any kind of treatment at all, we equilibrate the patient into CR. If need be, we can mount our diagnostic models and perform and trial equilibration on the mounted models prior to the actual equilibration in the mouth so we know the expected occlusal outcome once we get to the mouth. The equilibration would then be replicated in the patient's mouth. The key to this option is after equilibration all of the previous methods of treatment in ICP apply to CR, as they are now the same.

Option 2: Mount models in CR, equilibrate and diagnostic wax models. Another way to treat these patients is to mount the models on an articulator in centric relation using a facebow and CR bite records. Lets say you were planning or restoring the upper posteriors and you wanted to restore them in CR. The models could be equilibrated into CR (mainly at the expense of the upper posteriors as compared to the lower posteriors). Once the models have been equilibrated, the upper posterior teeth can be diagnostically waxed. Back in the mouth, we now prepare the upper posterior teeth and equilibrate the anterior teeth.

Once the anterior teeth are equilibrated into CR, go back and check the interocclusal distance on the posterior preps to make sure you still have enough occlusal reduction, take the final impression, and make the provisionals. Since the teeth were waxed on the models in CR, a matrix taken from the wax-up can be used to fabricate the provisionals. The provisionals will then fit into the new CR occlusal scheme.

Option 3: Mount case in CR and perform diagnostic waxing in CR. This option is fairly similar to the previous technique in that we are going to use the diagnostic models mounted with a facebow and centric relation bite records. Rather than equilibrate the models, we will instead diagnostically wax the case. Given that the models are mounted in CR, the wax will end up in CR as well. This technique then is generally used when you are planning on restoring ALL of the teeth. Back in the mouth, you would prepare the teeth and then equilibrate the provisionals in CR.


Commenter's Profile Image GEORGE GKRITZAPIS
June 26th, 2013
thanks a lot.i was a Frank Spear student in Phoenix and i learn a lot there,thanks again!
Commenter's Profile Image Daniel
June 27th, 2013
Though I agree with most of what is said here, there are very important pieces that are missing. I have owned my laboratory for 30 years of which I have worked in the world of centric retaliation for about half that time. I will say however I truly appreciate anyone who is trying to take dentistry to a higher level. So to that end well done Dr. Spear.
Commenter's Profile Image CARLOS MAS BERMEJO
July 1st, 2013
This is the best method to start any rehabilitation. Thank's Frank and Gregg. All things that i learn in this course ,works
Commenter's Profile Image Ralph Nicassio, DDS
July 16th, 2013
The notion that establishing CR and mounting casts with a facebow will permit stable opening of a bite is one of the greatest myths in dentistry and a great disservice to patients and dentists trying to perform to the highest possible care.
Commenter's Profile Image Lawrence Gottesman, DDS
July 16th, 2013
Well said Dr. Nicassio. There are some really important concepts that are clearly missing here and should be cleaned up. Unfortunately, the CR community is highly vested in the concepts as the "go to" approach that is primary to all diagnosis. First, where is the joint loaded and where is it unloaded? If you can answer this question and understand that joints must be able to achieve both positions as essential to normal function and physiologic fulfillment then you cannot accept CR as any position other than a temporary reference position when the occlusion must be changed or in the edentulous state. Secondly, the concept of "task dependence" has not been discussed very much in dentistry. While many teachers of the CR philosophy would have you believe there is a very precise centric relation position, the literature would vigorously support that there are clear differences between a bimanual manipulation, leaf gauge, AMPS, deprogramming appliances and the length of time for which they are utilized, including long-term splint therapy for establishing the optimum condylar displacement values in order to achieve the most stable position. This is not only an unpredictable and unstable position, but is a border path position which is loaded! The transfer of recorded information is filled with occlusal discrepancies as anybody knows who has been frustrated by the extensive posterior prematurities in appliances and restorative cases. Also, there are many cases restored in CR which have delayed or immediate anterior fremitus. There are many more insights to be learned beyond this short discourse. Ralph, you hit the nail right on the head and I am glad to see I'm not alone in this voyage! Thanks, Larry
Commenter's Profile Image Micah Parkhurst, DDS
July 18th, 2013
There are some key concepts missing here because this was not intended to be a soapbox lesson on why you should use CR. Admittedly I come from a CR background, but one of the most refreshing aspects of studying with Frank and Gregg is the lack of a dogmatic approach to dentistry. This short vignette was meant to provide information on how to take the information you gather from mounted models and use it as an aid in treating the patient. The following is a quote from the lead-in to this article: "If we choose to now restore our patients in centric relation, how do we then get the information from our centric relation mounted models back to the patient? The good news is that we have more than one option when deciding how to restore the patient in centric relation." Notice the word "if" in the opening sentence. The info in the above article is of use if and when we decide to use CR as a treatment position.
Commenter's Profile Image Glenn Chiarello
July 18th, 2013
geeze, i had to chime in and agree with Micah.
Commenter's Profile Image Lawrence Gottesman, DDS
July 18th, 2013
Micah: It is not my intention to broadcast from a podium with malcontent. I am so sorry if you and others construe this as offensive. My simple point is that we have much to learn within the construct of CR as a position free of problems. If we do elect to use this as a reference position, the unwitting student/practitioner may find that difficulties can arise and become frustrated. I would rather you see this as a gesture of learning. I think rather than labor on the intent of the wording you could focus on the value I am trying to provide. Please forgive me if you saw something in the tone that was caustic and unbecoming. Larry
Commenter's Profile Image Jack Love
July 19th, 2013
Frank, Have you and Vince done any work with finishing orthodontic cases in C.R.? It would seem to me that doing an orthodontic case is really a "full mouth" restoration, only done with orthodontics??? Jack Love (C.J.)