The patient presents with a fractured distal lingual cusp of his porcelain crown on #19. There was also a 6mm pocket on the mesial lingual of #19. All other tissues were healthy and probed within normal limits. We now need to ask, “why did the crown fracture and is the perio issue related.” This patient has beautiful posterior dentistry that unfortunately is not working together with the condyles, bones and muscles. This is an occlusion case first and a new crown later.
The digital force scan shows that the envelope of function directs all the occlusal force into the location of the fracture. The next cusp to fracture is the distal lingual of #18. Why would all four lower molars require crowns, and #19 have an endo, bone loss, and fractured porcelain? The force on the posterior teeth, especially the posterior left has always dominated this occlusion because the canines never did function to protect them. This force pattern was visible at age 15, as it is today. Force patterns are diagnostic years ahead of the pathology. Force scans are proactive in that they predict the future. If #19 was replaced and built out of occlusion, then #18 would fracture next.
The patient has a dysfunctional envelope of function caused by the lack of canine guidance and dominating destructive force in the posterior. Our suggestion to the patient was to balance the posterior forces, establish canine guidance, and treat the local periodontal issue, in that order. This will all need to be done so that the new crown could be placed in harmony with his occlusion. A comprehensive muscle and TMJ exam from the neck forward and deprogramming splint were made first. The next appointment will be another diagnostic appointment that includes facebow, models, and centric records. The equilibration and perio treatment were all completed and now that the destructive forces are treated, the tissue has a chance to heal. Digital Occlusion is made for cases like this. Patients can see the dysfuctional patterns on the computer and have no problems understanding why establishing good function needs to be the priority.
Future dentistry is easy, predictable, and painless now that the occlusion is functional. As with all of our patients, his occlusion will be monitored during hygiene and recall exams. Usually these patients are grateful because they know that you know their mouth better than any dentist ever did. They feel the difference when the occlusion is corrected and the dentistry is balanced.