If you are interested in understanding the process the lab uses to cross-mount a case or are cross-mounting your own cases and want to avoid potentially introducing error into the procedure, I suggest you complete the steps in the following order. Doing so increases the predictability that the esthetics and function of the case will meet with you and your patient's expectations.
- Using the facebow, mount the patient approved provisional case.
- Mount the opposing mandibular cast (natural dentition or a cast of the provisionals).
- Once the mandibular cast is mounted, then the cast of the maxillary preparations is mounted with a bite registration to the mandibular teeth or provisionals, again at the vertical dimension of occlusion.
- The cast of the mandibular prepared teeth is now mounted to the cast of the maxillary provisionals.
- When taking the bite registration in an extensive case, the maxillary and mandibular anterior provisionals are left cemented to establish the vertical dimension of occlusion and establish the anterior stop. This bite is now used to mount the cast of the maxillary prepared teeth.
This completes the steps involved in the cross-mounting of casts. Remember, this process helps the lab verify the information sent from the doctor's office and increases the likelihood that the cementation process is smooth and uneventful.