Diagnosis and Pre-Treatment of Worn Dentition Cases
Severe wear type cases present special challenges as well as opportunities for the doctor/technician team. A critical first step is to properly diagnose the cause of the wear. From occlusal interferences, to parafunctional habits, to chemical erosion, the causes can be varied but should be an important part of the diagnostic process. On severe wear cases, a CR/MI discrepancy can actually be your best friend. The back and up seating of the condyles will often result in a down and back repositioning of the lower anterior teeth, creating much needed restorative space. Knowledge of the proper CR treatment position can often result in an “easier case" with fewer teeth involved. Properly mounted casts in centric relation are a key first step in the process, along with a complete series of clinical photographs.
Once a diagnosis has been made concerning a cause, the diagnostic work-up process can continue. We often recommend computer imaging
at this point to help patients focus on the future possibilities. The cost is minimal, and the impact is powerful. With the patient understanding the nature of the problem, the implications of non-treatment, and the possibilities of phased treatment to solve the problem, your percentage of case acceptance should be extremely high.
Determinants of Treatment for Worn Dentition Cases
Treatment wise, worn dentition cases present special and unique challenges in terms of determining exactly what to do. Creating centric stops and anterior guidance is relatively easy on most cases, but that alone is not enough to proceed. To really analyze the problem and achieve optimum results, the photographs
must be carefully studied and a number of critical determinations made:
Wear due to bulimia. Typically, as the lingual surfaces of the upper teeth erode, the lower teeth erupt.
Severely worn dentition case due to multiple causes: CR/MI discrepancy; over-contoured upper restorations; severe exostosis.
Increasing vertical is contraindicated in the presence of moderate or severe exostosis.
- Which arch has worn - upper, lower, or both? Anteriors, posteriors, or both?
- Has eruption kept up with the wear?
- Do the teeth need to be lengthened? Incisally, gingivally, or both? Uppers, lowers, or both?
- Do we need to increase occlusal vertical dimension (OVD), or does correcting a CR/MI discrepancy provide enough occlusal space to restore the anterior teeth to proper form and function?
- Is exostosis present to further complicate changing vertical? Has the neutral zone lingualized the upper anterior teeth?
- Is the envelope of function restricted?
These are the types questions we would evaluate with your mounted casts and photographs. We usually start with simply looking at the length of the lower anteriors at rest and in speech. If they have erupted and appear too long, they may even need to be shortened. If too short, they may need to be lengthened incisally. If so, do the upper lingual’s need to be reshaped first to make room?
All this thought process and evaluation is part of the comprehensive case work-up the doctor and lab should do together. Many times, the periodontist and orthodontist also need to be brought in to the discussion on a more interdisciplinary level. This is comprehensive dentistry.
It is what we love to do, and we welcome the opportunity to help you with your next case.