Form and Function in Cosmetic Dentistry

Sometimes great opportunities present themselves in our dental office, and unless we are careful to identify them, they can easily slip away. When that happens, there are 3 losers. The dental office loses because it does not get to do a great and productive case; the dental profession loses because the level of education and awareness in the community about dentistry does not get elevated; and of course, the biggest loser is the patient, who does not get the care he or she really needs and wants.

Figure 1. Female patient, age 51, upon presentation to the office.

A female patient, Bonnie, visited the office for a "cleaning and checkup" (Figure 1). She had not been to a dentist for "several years" and had no specific complaints. She thought that everything was fine. Her hygiene evaluation detected some gingivitis and moderate pockets (4 to 5 mm) that would likely respond to scaling and root planing in conjunction with much needed improvement in her home care.

In many dental offices, the patient visit may have ended there, with a new toothbrush and a few spools of floss, but we did a more in-depth interview and examination. Specifically, I asked if she was happy with her smile, highlighting the following:





Figure 2. Space between teeth Nos. 7 and 8.

• color of her teeth

• space between teeth Nos. 7 and 8 (Figure 2)

• older posterior restorations

• gum recession.

The appearance of her teeth was a concern for Bonnie, but her apprehension about dental care outweighed her concern about aesthetics. She did confirm that the space between the teeth was unpleasant, as it frequently trapped food. In addition, she commented that she frequently experienced soreness in tooth No. 7. An examination revealed that there was definite fremitus (movement on biting). Tooth movement from occlusal forces demonstrated that the patient was either grinding or clenching her teeth, or both. Patients who are grinding and/or clenching their teeth are usually responding to occlusal interferences that are prohibiting the condyles from centering during maximum intercuspation.1 In addition to damage such as recession, abfractures, or tooth movement, the patient might also have joint damage and/or head, neck, and facial pain (which could be due to masticatory muscle overload2). Joint damage can manifest as joint sounds (popping, clicking, or crepitus) from a deranged disc, pain in the joint, or degenerative joint disease, with or without pain.

The patient reported a multiyear history of intermittent clicking in her right ear. As a follow-up, I asked about any headaches. She reported a long history of chronic, tension-type headaches and occasional migraines that she self-treated with NSAIDs. Bonnie was willing to be reappointed for a complete exam because during her, I-just-want-a-cleaning-visit, we identified issues together that were relevant to her and for which we might be able to help.

Many different theories and opinions exist about bite issues, so when I communicate with patients and other professionals, I focus on basic biomechanics and tooth and joint stability and stay away from the controversial buzz words. I am looking for teeth that are being adversely affected by force overload or muscles that are being overworked and causing pain.

She returned for her follow-up visit 8 days later. The objective of my evaluation was to determine if excessive and unbalanced biomechanical forces were acting on her occlusion. I also wanted to determine if there was a correlation between those forces and her headaches, muscles, or joints. Finally, I wanted to determine the condition of the jaw joint and supporting structures. Many head, neck, and facial pain issues have nothing to do with the teeth or joints. All too often, the dentist finds a patient who really has a dysfunctional bite and also has head, neck, and facial pain, and makes the assumption that there is a cause-and-effect relationship between the two. Sometimes there is, and sometimes there is't. If the well-meaning dentist provides treatment before proving a connection, and there is no connection, the treatment will fail because bite treatment cannot possibly stop pain that is not due to bite issues. The result is inevitable treatment failure, which damages patient confidence and reflects poorly on the profession in the eyes of the public and medical community.

Since three separate issues are related to bite problems (biomechanical dental disease,3 muscle pain, and joint damage), they must be evaluated separately. Space does not permit more than a brief discussion of these issues.

Bonnie's joint sounds indicated a derangement in the disc assembly. The damage could have resulted from macro trauma, such as whiplash injury or a blow to the face or head. This is similar to skiers falling and damaging their knee joints. Damage can also result from microtrauma such as ongoing clenching and grinding.4 This is analogous to people who have spent many years jogging on hard roads or tracks and develop damage to their knee joints. Orthopedic physicians are trained to examine and evaluate the knee joints, and the public has been educated to understand the concept of macro trauma and microtrauma as they affect their knee joints. On the other hand, most dentists graduate from dental school with no education about the jaw joint, and the public is equally unaware. As a result, knee injuries are well understood, but to many the jaw joint remains a great mystery.

When evaluating the jaw joints for damage, I looked for the following:

Figure 3. Doppler is used to listen to joint sounds.

(1) Audible sounds either reported by the patient or detected by Doppler auscultation with a product such as the Mini Doppler from HNE Health Care (Figure 3). Impairment/reduction of range of motion in all directions.

(2) Pain during joint loading (pushing from under the angle of the mandible directly up toward the ears), which indicates either damage in the joint or muscle bracing. This can be differentiated by deprogramming the muscles to allow the condyles to achieve a centered position, which is unbraced by muscles, to see if the pain stops.5

Deprogramming the muscles to diagnose occlusal muscle-related head, neck, and facial pain has been a standard of care for many occlusally aware dentists since the 1920s. It is the best and fastest way to differentiate occlusal muscle pain from pain in the joint or other unrelated head, neck, and facial pain such as primary migraines. Early references include Long's published articles describing the use of a leaf gauge.6 In 1975, Dr. Peter A. Neff published TMJ, Occlusion and Function, in which he described his concepts of anterior deprogramming. Dr. Peter E. Dawson has been teaching dentists to make custom deprogrammers for more than 35 years.

Figure 4. Best-Bite Discluder centers jaw joints and relaxes muscles.

When Bonnie arrived at the office for her complete examination, she had a moderate tension headache with pain on the VAS (visual analog scale) of 6 out of 10. She also reported some pain in the right joint upon loading. I used a fourth-generation deprogrammer, Best-Bite Discluder (Best-Bite), as part of the diagnostic process for bite-related headaches. The preformed Best-Bite Discluder was customized by lining it with bite registration material and setting it on the patient's upper central incisors (Figure 4). It is completely flat from side to side and front to back, allowing unrestricted and smooth movement for the lower incisors. The 8º incline of the occluding side encourages the lower incisors to track back and upward gently so as to guide the condyles into a centered position and simultaneously help relax the muscles.7

Once Bonnies condyles were centered and her muscles relaxed, her tension headache was reduced to a zero (out of 10) in approximately 3 minutes. I then "loaded" her joints without any discomfort, indicating that the muscles were no longer splinting and that the pain was entirely due to muscles. There was a reciprocal click on opening and closing, so the disc was sliding off the condyle during opening and then recapturing during closing, but the deprogramming proved that there was no related joint pain. Based on the ability to load the joints without pain, surgical intervention in the joints was not indicated even though there was definitely internal derangement that was causing the clicking.5

The pain relief was quite a surprise to Bonnie, as she had seen many dentists in her years as a dental patient and never had her headaches connected to her bite. By relieving Bonnies pain as the very first step in just a matter of minutes, a tremendous amount of patient confidence and energy was created to move the case forward. Not all patients who have head, neck, and facial pain can attribute any or all of the pain to muscles caused by their bite. Some patients might have headaches due to their bite and perhaps neck or shoulder pain that is due to a cervical or neck injury. It is important to note that if a patient does indeed have a biomechanical bite issue and pain, but the pain is not caused by the bite, then the dental treatment will restore the teeth and improve function and cosmetics, but it will not affect the pain. This is important for dentists and patients because it ensures that proper treatment expectations have been set before the case is treated.

Figure 5. Bite registration material captures posterior bite record.
Figure 6. Whip Mix facebow captures approximate condylar axis of rotation. Figure 7. Case mounted using Best-Bite Discluder and posterior bite records on Whip Mix articulator.


A great quote I think about in any restorative case is the title of a chapter in The Seven Habits of Highly Successful People, a book by Stephen Covey: Begin With The End In Mind." For this reason, I captured bite records with her condyles centered and muscle relaxed for study model mounting and treatment planning. This was accomplished by injecting bite registration material between the posterior teeth at the comfortable position established by the Best-Bite8 Discluder (Figure 5). The articulator system I chose for this case was the Whip Mix Model 2240 articulator and Whip Mix Model 8645 Quick Mount facebow (Figures 6 and 7). Any articulator system faces the same reality that is faced with computers: garbage in/garbage out." In other words, regardless of the precision of the articulator system, the information it provides is only as good as the bite record. That is why deprogramming the muscles is so important, since this allows an accurate bite record.

The Whip Mix system was ideal for this case. The facebow requires minimal adjustment and is very fast and easy for a staff person to utilize. The facebow mounting allows the dental technician to have a standard reference for the anterior occlusal plane, which is important for correcting or preventing canting of the anterior teeth. The customization of the incisal table and the ability of the instrument to accept quick and easy lateral bite records for protrusive setting are of great help if the dentist wishes to utilize these techniques. In addition, the precision of the Whip Mix system and magnetic mounting rings allows the dentist to transfer the casts on the rings to the dental laboratory, where the technicians can mount the case on their own articulators. This allows the dentist to keep his or her instrument in the office for use with additional cases and prevents damage during shipping. Two or 3 articulators will suffice for most dental offices.

TREATMENT

 

Phase 1

Figure 8. Space closed naturally following equilibration.

Step one was a full equilibration to create a coincidence of centered condyles with full intercuspation of the teeth as well as anterior and canine guidance.9 (Since true centric relation requires the discs to be normal, and this patient does not and never will have normal discs, this patient was actually in adapted centric posture.10 This is defined by Dawson to indicate that the condyles are in a centered position unbraced by muscles with full intercuspation of the teeth as well as anterior and canine guidance.) The result was that the headaches stopped and the anterior space closed all by itself (Figure 8). Equilibration is one of the most important services that can be provided in the dental office because it does 3 important things:

(1) It optimizes the forces on the teeth and supporting structures so that the potential for dental damage is minimized. It directs the vertical closing forces generated by the jaw muscles down the long axis of the posterior teeth as much as possible. This is critical, since they are closest to the jaw joints (fulcrum) and therefore subject to the heaviest loads. At the same time, when the person bites, it also directs the nonaxial forces side to side as far as possible from the fulcrum, where the forces are weakest (anterior and canine guidance).

(2) It reduces muscle activity and thereby the forces on the jaw joints to reduce pressures on the joints and on the disc to minimize damage going forward.11

(3) By reducing muscle activity, it reduces pain that is due to or stimulated by muscles.7

This was accomplished over 4 visits by deprogramming the muscles and centering the jaw joints with Best-Bite Discluder. First, the patient's muscles are deprogrammed to allow the jaw joints to center in the fossa. Then the patient bites on Madam Butterfly (Almore) marking ribbon to create contact marks with the joints in the critical centered position. Any marks that identify premature and nonaxial loading on the posterior teeth are removed, and then the remaining marks that are on cusp tips and fossa or marginal ridges are fine-tuned so as to create equal and simultaneous pressure on as many of the posterior teeth as possible.

After 2 or 3 recordings with the marking ribbon, the jaw sliding is likely to re-engage the muscles, so Best-Bite Discluder is used again for 30 seconds to recenter the jaws, relax the muscles, and ensure that adjustments are being made in the centered jaw position. For this case, Midwest 1157 rounded end carbide burs were used for the equilibration process (DENTSPLY). Several visits are allocated for this process, because the teeth will rebound after adjustments to equalize pressures, the muscles will adapt to the new occlusal relationships, and the process of adjusting the bite is fatiguing for the patient.

After 4 weeks with her new occlusion and the longest period she had gone without a headache in 24 years, Bonnie had overcome her distrust of the dentist and returned to discuss other treatment recommendations.

Phase 2

My complete treatment plan was as follows:

(1) Replace the old and worn posterior bridges and porcelain crowns on the upper central and lateral incisors.

(2) Perform aesthetic periodontal surgery.

(3) Provide new lower incisor crowns.

(4) Bleach the remaining lower teeth.

Based on the positive experience with the occlusal adjustment, Bonnie, who had avoided dentists for several years, was ready to confidently proceed with a comprehensive treatment plan.

The first step was to remove the old PFM bridges on teeth Nos. 3, 4, 6, 11, 13, and 14 by cutting through the porcelain with MLX diamond burs by Diatech. After penetrating through the porcelain, I switched to new Midwest 1158 carbide burs to cut through the metal framework. A DiagnoDent caries detec-tor (KaVo) was used to ensure that all remaining caries was fully excavated.

Composite cores were fabricated for the abutments using 38% phosphoric acid etch (Pulp-dent) and bonded with Bond 1 (Pentron) and Herculite (Kerr). After the carious areas were sealed, the teeth were reprepared and temporized with Luxatemp (Zenith/DMG). Then the pa-tient was referred to the periodontist for pocket elimination in the posterior segments and aesthetic crown lengthening surgery in the anterior segment.

 

Figure 9. Impression for final restorations. Figure 10. Bite record for final restorations.

After 3 weeks, the patient returned to the office to reprepare the posterior teeth and remake the posterior temporary bridges. We waited for the tissues to mature prior to removing the old anterior porcelain crowns on the front teeth and taking final impressions. Healing continued uneventfully for another 6 weeks. The final preparations were accomplished for the posterior teeth and the 4 incisors, impressions were obtained with Aquasil heavy and ultralight (DENTSPLY, Figure 9), and a segmental bite record was captured with the posterior temporary restorations removed before the anterior teeth were prepared (Figure 10).

Digital photographs and study models were obtained of the temporary crowns and bridges as a guideline for the laboratory technicians. The desired shade and preparation shades were also recorded so that the feldspathic porcelain crowns on the incisors could be matched to the porcelain of the PFM fixed bridges. The patient was particularly concerned that the teeth not appear "unnaturally white, so we selected the shade A1 with incisal halo and moderate surface texture.

Figure 11. Final PFM bridge.

The crowns and bridges were fabricated by daVinci Dental Stu-dios to the specifications of the dentist and patient (Figure 11). The posterior bridges were cemented to the teeth with Rely X (3M ESPE), and the anterior porcelain crowns were bonded to the teeth with the Insure system using light-cured clear shade (Cosmedent) with the same steps as were used to bond the composite cores. The Rely X cement was given a 2-second cure with the Argon Laser (ILT Systems), and the excess was removed immediately with an explorer and dental floss before final hardening. The porcelain crowns were spot-cured to tack them into position, and the excess Insure material was removed with dental floss and a rubber tip. Final cure was accomplished with the Argon Laser. The slight remaining excess was removed with hand instruments and then 16 Midwest bladed needle-tip burs. Final finish was accomplished with diamond polishing strips (Premier) and Midwest super small polishing burs. This was followed by fine, extrafine, and superfine enamel and porcelain polishing points from the Shofu porcelain polishing kit (fine with no ring, extrafine with yellow ring, and superfine with white ring).

Figure 12. Occlusal contacts in mandibular arch after equilibration. Figure 13. Occlusal contacts in maxillary arch after equilibration.
Figure 14. Final case establishes ideal aesthetics and function.


Figures 12 and 13 show the final occlusion after equilibration and placement of the restorations. Due to the careful pre-planning and programming and the success of the temporary restorations (aesthetically and by finalizing the occlusion in phase 1), there were no surprises during the delivery visit, and the patient was very pleased with the final result (Figure 14).

SUMMARY

The results of the case presented meet the aesthetic requirement of the patient as well as the biomechanical and functional requirements for long-term comfort, function, and stability. If not for the extra time spent with the patient uncovering the relationship between her occlusion and headaches and gaining her confidence by solving that problem first, we never would have had the opportunity to build a relationship that would allow her to proceed confidently with the cosmetic treatment that she described as the "best darn holiday present ever!"


References

1. Okano N, Baba K, Akishige S, et al. The influence of altered occlusal guidance on condylar displacement. J Oral Rehabil. 2002;29:1091-1098.

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

3. Simon J. Biomechanically-induced dental disease. Gen Dent. 2000;598-605.

4. Piper M. Piper Classification System. Unpublished lecture material. October 20-21, 2004. St Petersburg, Fla.

5. Dawson PE. Evaluation, Diagnosis, and Treatment of Occlusal Problems. 2nd ed. St Louis, Mo: Mosby-Year Book; 1989:39-44.

6. Long JH. Locating centric relation with a leaf gauge. J Prosthet Dent. 1973;29:608-610.

7. Goldstein L, Gilbert LM. Use of the BEST-BITE anterior discluder for the treatment of migraine headache: a case study. Funct Orthod. 2004;21:34-37.

8. Karl PJ, Foley TF. The use of a deprogramming appliance to obtain centric relation records. Angle Orthod. 1999;69:117-124.

9. Parker MW. The significance of occlusion in restorative dentistry. Dent Clin North Am. 1993;37:341-351.

10. Dawson PE. New definition for relating occlusion to varying conditions of the temporomandibular joint. J Prosthet Dent. 1995;74:619-627.

11. Neff, PA. TMJ, Occlusion and Function. Washington, DC: Georgetown University Dental School; 1975:60.


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.

Banner