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.