Is it time to re-define occlusal trauma?
Mrs. P, a 45 year-old woman with an unremarkable medical history was referred to me for TMJ and occlusal evaluation by her prosthodontist. She had had periodontal surgery involving all the upper teeth the previous year and now was in the process of full mouth reconstruction. Most upper teeth already had final restorations in place, although a few were still in nicely done provisionals.
The main concern of both the patient and her restorative dentist was continued periodontal breakdown, especially involving the first and second molars on the upper right. Periodontal pockets measuring 7 mm or more had been corrected with osseous surgery but now, a few months later, those defects were back and there was talk of possible extraction and implant placement.
Tooth #5 had recurrence of marginal inflammation and 4 mm probing scores although the pockets had been eliminated at the time of surgery. This was also true of #13.
The periodontist was obviously concerned by this apparent lack of healing.
On examination in my office I found that Mrs. P did not appear to have a TMJ problem. Joint x-rays were normal, she had no abnormal joint noises, and she had normal range of motion.
T-scan occlusal analysis showed heavier contact force on #2 and 3 than anywhere else. See figure 1. Notice that #13 also had heavier than normal contact.
However, those centric contacts were not as significant as her working and non-working side interferences.
Below is a T-scan of right lateral excursion. Notice that she does not have canine guidance and that all right side posterior teeth have heavy contact. Could this influence healing of the periodontal surgery sites? We would find out within a couple of months.
Next is a T-scan of left lateral excursion. Again you can see that there is no canine guidance with heavy interferences on teeth #13 and 14.
Published studies on any possible relationship between occlusal trauma and periodontal disease are not only inconclusive but contradictory.
I think it is clear from several studies that occlusal trauma alone will not cause periodontal disease. In a 1986 article (Journal of Periodontics, Nov. ’86), A.M. Polson weighed the relative importance of bacterial plaque and occlusal trauma. In every case observed, the presence of virulent bacteria always trumped trauma as a causative factor.
However, Bruce Pihistrom in the January 1986 Journal of Periodontics states, “Teeth with both functional mobility and a radiographically widened periodontal ligament space had deeper probing depth, more clinical attachment loss and less radiographic osseous support than teeth without those findings.”
Nunn and Herrel writing in the April 2001 Journal of Periodontics state that teeth with no observed occlusal trauma were 60% less likely to worsen in probing depth, bleeding points, etc. than teeth with occlusal trauma based on mobility, fremitis, and occlusal wear.
After my exam of Mrs. P, I spoke with her restorative dentist and forwarded copies of my T-scans. She returned approximately two months later for re-exam.
T-scan of C.O. (or MIP) showed significant improvement with much more even occlusion. Teeth #4 and 13 continued to show hard occlusal force.
T-scan of right lateral excursion shows that most of the working side interferences have been eliminated. Canine guidance is still lacking and there is still working side contact on #3. I have suggested re-restoring both maxillary canines, though first pre-molar guidance may suffice.
Most of the left side working interferences have also been eliminated.
What about the periodontal condition? During the interval between the June exam and the August reappraisal I found that the probe scores around #2 and 3 had improved greatly though still not to normal (<3mm) levels. There has been enough improvement that extraction and implant placement are no longer being considered.
There was still redness and 4 mm probe scores around #5 and 13.
I have not re-examined this patient since her August visit in my office—it has only been a few weeks as of this writing. However, her dentist has informed me that he has done further refinement of occlusion and the observed inflammation around #13 has resolved and that the pocket depth has decreased.
It seems clear in this case at least that relieving hard occlusal contact in C.O. and, probably more importantly, eliminating working and non-working side interferences has had a positive effect on the patient’s periodontal status.
But, did she have occlusal trauma? In my opinion she did.
In an on-line article, New York periodontist Dr. Alessandro Geminiani states, “In a clinical study it is difficult (if not impossible) to know if a tooth is suffering occlusal trauma. Therefore most of the studies used other criteria such as mobility, occlusal wear or parafunction to access the link between periodontal disease and occlusal trauma.”
I believe that given current technology we can do much better than that. I think we’ll find that any posterior tooth that has more than minor occlusal contact when the patient moves into right and left excursion is suffering occlusal trauma whether you observe mobility or occlusal wear or not. I actually think that there should be NO posterior tooth contact on lateral excursion. I think that using the criteria of mobility and occlusal wear ensures that we spot occlusal trauma much too late. Computerized occlusal analysis allows us to clearly see lateral interferences and restorations with pre-mature contacts with much more accuracy than was ever possible with simple articulation paper.
Yes, the marks produced when using articulation paper may give you some indication, but computerized occlusal analysis will provide a much clearer picture of what actually occurs during a patient’s excursive movements.
In Mrs. P’s case, a very skilled prosthodontist, utilizing standard techniques for analyzing occlusion was not able to observe the degree to which occlusion might be affecting periodontal status. T-scan provided him a road map of sorts to aid in correcting the problem.
Mrs. P would still be helped with better canine guidance, and her dentist may need to replace the maxillary canine restorations. And I obviously do not believe that occlusion caused her periodontal problems. Bacterial plaque had to play the primary role. Meticulous home care and frequent follow-up with her dental hygienist will be needed, likely for the rest of her life. Bacterial plaque will need to be held at bay. Meantime, careful attention to occlusion has gone a long way to improving this person’s periodontal status.
Note: I do not have any financial interest in the Tekscan Company, the makers of T-scan.