Occlusal Interference: Dentistry's Great Imposter

Figure 1. Patient presents with teeth showing wear.

Patients in pain are sometimes difficult to diagnose if the pain is not caused by one of the classic etiologies such as deep decay leading to pulpitis, periodontal abscess due to a very deep pocket, or inflammation due to an impacted wisdom tooth. This article presents one of the more puzzling cases in which the patient was skeptical about the cause of her long-term pain.

CASE REPORT

The patient was a woman in her early 50s who presented with severe pain in her lower incisors. She stated that they were broken, painful, and “needed capping.” The teeth were very sensitive to percussion and temperature and had slight mobility but no radiographic evidence of any periapical pathology. The only visible problem was an odd pattern of wear that could only be due to tooth grinding (Figure 1).1

On questioning the patient, she stated that she had experienced severe pain in the lower incisors for several weeks and had been to her regular dentist several times with no success. She was convinced that she needed to get her lower teeth capped to solve the problem. Fortunately for her, her former dentist could not find the problem and did not think that capping her teeth would provide the solution. He referred her for endodontic evaluation, but she was afraid of root canal treatment, so she broke the appointment and scheduled an appointment at my office for another evaluation.

Since she had such severe wear on her teeth, a deep bite, and spaces between her maxillary anterior teeth, I wondered if her bite could be a factor in the pain and positioning of her teeth.2 I asked her if she ever experienced any headaches or jaw pain. She replied that she had over a 20-year history of migraines, and additionally she experienced severe jaw pain, but she was certain that this had nothing to do with her recent tooth pain. She stated that her headaches were diagnosed by her medical doctor as migraines and had been reoccurring for more than 20 years. The tooth pain was recent. When I asked her if she was aware of clenching or grinding her teeth, she strongly denied that she ever did this (even though the “broken” maxillary and mandibular teeth fit together perfectly, indicating that the missing tooth structure was indeed due to wear).

With the accumulating evidence that her bite might be a factor, I switched tactics and began a detailed occlusal examination, noting other patterns of tooth wear that could only be due to tooth clenching and grinding. Then I began to examine her jaw muscles to see if there was a pattern of pain.3 Her masseter and temporalis muscles on both sides were very sore to even gentle palpation. Additionally, she reported pain down her neck. Finally, I palpated her lateral pterygoid muscles, which were acutely painful to palpation.

Figure 2. Worn teeth fitting together.

In examining her bite, I found that if I relaxed her jaw muscles and manipulated her jaws into a centered jaw position by gently pushing down on her chin and simultaneously lifting up from under the angle of the jaws, as taught by Dawson,4 I could get her to gently tap together, noting that she only contacted the premolars on the left side. When she continued to maximum closure, it was necessary for her teeth to slide forward and to the left. In addition, when she tried to slide onto her left molars to chew, she hit on the right molars. When she attempted to grind onto the right molars, her left molars interfered. And when I asked her to move into protrusive position, the worn teeth in the front fit together perfectly, proving that she was grinding her teeth (Figure 2).

As a result of my examination and findings, I determined that the problem was in fact a combination of occlusal muscle pain (sometimes referred to as TMJ pain) and biomechanical dental disease due to tooth clenching and grinding.5 Unfortunately, the patient completely disagreed with me. She was certain that she had a combination of migraine headaches, unrelated jaw aches, and lower teeth that needed capping. She completely denied that she was grinding her teeth and wanted those painful lower teeth fixed “now.”

CONVINCING THE PATIENT

Even though I had all of the evidence that I needed for a diagnosis, I did not have 100% proof positive that the patient’s bite was in fact the cause of her headaches or jaw pain, and she certainly was not convinced that her bite was the problem. The remaining task was to “connect the dots” between the headaches, jaw aches, painful teeth, and bite issues in a way that proved to both of us that the bite was the cause of both her dental damage and pain.

Dentists have been treating bite problems due to occlusal interference for many years. The gold standard for proving that the bite is the cause of pain has been to interrupt the occlusal interference to see if that would allow the jaw joints to center and stop the muscle pain. If that worked, then there was proof of a cause-and-effect relationship between the bite and the pain. Typically, this is done by constructing a bite splint to allow the jaw joints to center. Then, observing the pain symptoms of the patient wearing the bite splint would verify that the bite is, or is not, the cause of the pain. The problem was that my patient was not going to spend any more time and money on my theory. She wanted a result now or she would leave to find another dentist to cap her lower front teeth.

A fast way to center the jaw joints to see if the bite is the source of the pain is with the Best-Bite Discluder (Best-Bite Inc). It is a system that combines a customizable one-size-fits-all anterior discluder and custom liner material to fit on the patient’s teeth. The discluder quickly centers the jaw joints and releases any muscle fatigue and spasm.6 If the head, neck, or facial pain is in fact due to the patient’s bite, the pain will disappear, typically in less than 2 minutes. If the pain is not occlusal muscle pain, using the discluder will not relieve the pain, eliminating the bite as the cause of the pain.

My patient was losing patience with me at that point, but I convinced her to stick with me for just a few more minutes. I immediately placed the discluder on her front teeth. In no more than 30 seconds, she started to feel different. You could see her surprised look as 20 years of head and jaw pain literally melted away. She started with a pain level of 9 out of 10, and in just a few minutes, she reported that the pain in her head was less than 2 out of 10, and her jaw pain was completely gone. Even the pain in the mandibular anterior teeth was relieved.

When I removed the discluder and asked her to clench down, the tightness and pain in her head and jaws started to return. When I replaced the discluder and asked her to tap her teeth again, the tightness and pain immediately began to go away.7 Much to her amazement, she had to agree that her bite had to be at least part of the problem. Based on this result, the patient allowed me to continue her occlusion workup, and we agreed to delay capping the painful lower front teeth for at least a few visits.

Figure 3. Centric relation (CR) bite record captured with Best-Bite Discluder. Figure 4. Models mounted in CR.

The next step was to obtain diagnostic models and mount them on an articulator for further study. We obtained a facebow record with a Denar Slidematic facebow (Waterpik) and mounted the upper cast. To obtain an accurate centric relation (CR) record, we used the discluder to recenter the jaw joints to a pain-free position, verified as taught by Dr. Peter Dawson of the Dawson Center for Advanced Education. Once she was again in a pain-free position, we used a dab of polyvinyl adhesive on the underside of the discluder  to help retain a small amount of the bite registration material (Blu-Mousse Superfast, Parkell), and again had the patient close into the verified CR position. Once the incisor position was captured, we immediately used the same material between her posterior teeth for a posterior index on both sides (Figure 3). The posterior indexes plus the discluder were used to mount the opposing model on the articulator (Figure 4). The articulator selected was the Denar Combi (Waterpik).

Figure 5. Bite splint on articulator.

Once the models were mounted in CR position, we designed a long-term, full- coverage maxillary bite splint to support and stabilize the bite as well as keep the patient’s teeth and jaw muscles comfortable for a period of 3 months.8 The splint was a hard acrylic processed splint. It was designed to be permissive in that it did not have any posterior contacts other than in CR. In addition, it provided canine guidance and protrusive disclusion of the anterior teeth. The bite splint was inserted, and after several adjustments, the bite remained stable and the teeth continued to be comfortable (Figure 5).

After a period of stability, the models were remounted with new CR bite records. The occlusal relationships were analyzed on the articulator to determine if the patient’s current bite relationship could be equilibrated to achieve a comfortable, stable CR jaw position. After a trial equilibration confirmed that it was possible, the patient agreed to a course of treatment that would involve occlusal equilibration to eliminate the occlusal interferences to a centered jaw joint. Over several visits, we equilibrated the patient’s teeth to this CR position. After just one visit, she noticed a significant reduction in the headaches and jaw aches and improvement of the mandibular anterior teeth, even though she was no longer wearing the bite splint regularly. This immediate improvement gave her the confidence to finish the occlusal equilibration. The result was a complete reduction in her headaches and jaw aches with a marked reduction in the pain in the lower incisors.

Since the patient now trusted my judgment, she shared with me that she hated her smile and that the spaces between her teeth had been worsening over the years. She now realized that her tooth grinding and clenching were contributing to the movement of her front teeth. She assumed that I would finally cap those bottom front teeth.

She was still not correct. After obtaining a periodontal consultation, we determined that there were pockets around the maxillary anterior teeth that needed to be treated, and that in the process, we could raise the gumline and simultaneously shorten the incisal length of the maxillary anterior teeth, allowing me to place porcelain veneers to close the diastema, keep the teeth in proper proportion, and maintain the new bite we had created for our not-so-skeptical patient.

During the several weeks required for completing the equilibration, the dental laboratory created a diagnostic wax-up of the maxillary teeth, with the incisal edges positioned where I determined they would give us the correct functional and aesthetic result. Based on this fixed position, we worked backward to create a length that would allow us to achieve an ideal golden proportion length-to-width relationship of the central incisors. We then set up the length of the other anterior teeth to match. We fabricated a stent so that the periodontist had an intraoral reference point for the surgical procedure. The periodontist performed an apical repositioned full-thickness flap that simultaneously eliminated the periodontal pockets while maintaining the incisal papilla in the correct position, resulting in the proper length of the anterior teeth.

When the healing was complete, the teeth were prepared for modified porcelain veneers that covered the entire incisal edge and wrapped completely interproximally to close the diastemas. Transitional restorations were inserted that would mimic the eventual porcelain restorations, and the patient was given the opportunity to preview the restorations and verify that the functional aspects, including the phonetics, were acceptable. She was also given the opportunity to verify that the appearance was acceptable. The occlusal relationship was maintained throughout the restorative process. After it was determined that the transitional restorations met all of the objectives of the case, alginate impressions were taken, and the models of the transitional restorations, bite records, and the final impressions were sent to the laboratory for fabrication of the final porcelain restorations. Feldspathic porcelain was selected because of its ability to create internal colors and ideal contours with no metal that could compromise the aesthetic results.

Figure 6. Retracted view of finished case in the mouth. Figure 7. Unretracted view of finished case in mouth.

The final results show a pretty smile and a patient who is free of pain. By the way, we never had to cap those lower incisors because the pain that was due to excessive occlusal forces disappeared (Figures 6 and 7).

CONCLUSION

Pain that is due to occlusal interference can manifest itself as headaches, jaw aches, toothaches, or as a combination of all of them. The solution is to first diagnose the problem. If the pain is due to occlusal interference, relieving the bite problem will be the solution to the patient’s pain.


References

1. McNeill C, Mohl ND, Rugh JD, et al. Temporomandibular disorders: diagnosis, management, education, and research. J Am Dent Assoc. 1990;120:253-257.

2. Winocur E, Emodi-Perlman A, Finkelstein T, et al. Do temporomandibular disorders really exist? [in Hebrew] Refuat Hapeh Vehashinayim. 2003;20:62-68, 82.

3. Sipila K, Zitting P, Siira P, et al. Temporomandibular disorders, occlusion, and neck pain in subjects with facial pain: a case-control study. Cranio. 2002;20:158-164.

4. Dawson PE. Evaluation, Diagnosis, and Treatment of Occlusal Problems. 2nd ed. St Louis, Mo: Mosby; 1989.

5. Selna LG, Shillingburg HT Jr, Kerr PA. Finite element analysis of dental structures: axisymmetric and plane stress idealizations. J Biomed Mater Res. 1975;9:237-252.

6. Gilboe DB. Centric relation as the treatment position. J Prosthet Dent. 1983;50:685-689.

7. Becker I, Tarantola G, Zambrano J. Effect of a prefabricated anterior bite stop on electromyographic activity of masticatory muscles. J Prosthet Dent. 1999;82:22-26.

8. Skinner CE, Neff PA. The effect of non-surgical management of TM disorders. NDA J. 1994;45:14-18.



Dr. Simon has been an active dental practitioner in Stamford, Conn, for more than 30 years, with a focus on bite dysfunctions. The author of the book Stop Headaches Now: Take the Bite Out of Headaches, he can be reached at best-bite.com or (888) 865-7335.

Disclosure: Dr. Simon is the inventor of the Best-Bite Discluder.

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