By Martha Cortes, DDS
Cosmetic dentistry has seen many changes in the last 30 years, and only recently with neuromuscular dentistry has occlusion regained its proper place in the field. It is assumed to this day by many cosmetic dentists that function is inherent in the habitual bite and that there is no need to improve function as the bite intelligently evolves through proper occlusal biomechanics. The assumption is that the adaptive reserve of the oral cavity and of the body in general is sufficient to compensate for any gradual occlusal changes regardless of the source of change. The role of the general dentist is to eliminate any obvious pathology from the oral cavity, and if possible, to recapture the occlusion of a single tooth or a few teeth, and optimally maintain the teeth as is without further pathological breakdown. However, it is tacitly understood that the scope of the general dentist is limited and does not include enhancing the overall occlusion/function, nor does it directly enhance the esthetics of the oral cavity. On the other hand, the specialty of cosmetic dentistry is superficially seen by patients and doctors alike as an esthetic enhancement of the smile and nothing else.
However, cosmetic dentistry is aptly one of the best ways to enhance the oral cavity on all levels. Besides enhancing the smile, cosmetic dentistry ought to improve the functional biomechanics of the oral cavity. Ideally, this should be the role of any and all dentistry. Dentistry should enhance the structural integrity of the oral cavity and not deteriorate it. A flawed bite, however, cannot be enhanced by covering it up with a prosthetic façade, as this will only lead to further pathology and the eventual debonding and/or breakage of veneers and crowns, distressing both the patient and dentist. If the smile and/or face are dramatically asymmetrical, there is an immediate indication of structural imbalance that should be corrected before any strictly cosmetic work is undertaken. This will save cosmetic dentists time and money and lower their frustration levels as they will not have to constantly recement or redo their work. If we use the habitual bite as the foundation for a makeover, the structural integrity of the esthetics will depend vastly on the underlying neuromuscular imbalance. Misalignment in a restored smile will eventually lead to breakage, debonding, and exaggerated wear and tear in teeth and restorations, and is ultimately a disservice to the patient.
I began learning cosmetic dentistry during dental school with Dr. Norman Mohl, and prior to dental school while working for Heraeus Kulzer teaching dentists how to use new bonding materials. I studied with Dr. Peter Dawson immediately after dental school in 1986, and have continued studying with Dr. Frank Spears and Dr. John Kois, as well as studying occlusal systems, such as bioesthetics and neuromuscular dentistry in the late 1990s.
After practicing cosmetic dentistry for many years, I came to realize how important function is for the overall success of a case on all levels — both for the patient and doctor. I have taken my experience in cosmetic dentistry and have merged it with holistic, laser, and bioesthetic/neuromuscular dentistry. As a result, the patient benefits on all sides of the equation with a healthy, functional bite that is enhanced with materials that are beautiful and natural-looking. As doctors, we have to understand that once the teeth have been cut, altered, or reduced, there is no going back. Any dental work we do will greatly impact the entire chewing system in either a negative, neutral, or positive manner. True cosmetic dentists are both great diagnosticians and prognosticians. They see clearly the functional condition of the oral cavity and can see in advance how their work will benefit the patient. If a cosmetic dentist does not test the habitual bite prior to working up a case, how does she know that the bite is a healthy one? It is only by verifying the condition of the present bite that one can know what state it is in.
Cosmetic dentistry like anything else evolves. If it doesn't, it will be supplanted by something better. Functional cosmetic dentistry is the next step of which bioesthetics and neuromuscular dentistry form different camps. Sooner or later the consumer will require the cosmetic practitioner to become an expert in functional and occlusal esthetics. Nonfunctional cosmetic dentistry, as it stands, can only work successfully on those with a perfect bite, which is not the majority of the population. Besides, there are many people with very treatable TMD, headaches, and other mandibular-cranial problems who would love their pathology corrected while at the same time having beautiful esthetics. This population, which is quite large, is not being serviced by the cosmetic dental community, but instead is being bounced about between general dentists and surgical specialists. Furthermore, the field of cosmetic dentistry is swamped. It is not as it was 23 years ago when I started, where there were relatively few true cosmetic dentists. Today, many general practitioners call themselves cosmetic dentists with little or no training as such.
Functional cosmetic dentistry allows the practitioner to practice on multiple levels. It is a holistic and high-tech approach to cosmetic dentistry. By integrating the best from cosmetic, holistic, laser and bioesthetic/neuromuscular dentistry, you can have a very successful system of practice and approach. Many patients today want the very best from dentistry beyond just having a very pretty smile. They want to have that pretty smile with a very functional and healthy oral cavity, and without noxious materials adding any potential toxic load to the body. This will be the wave of the future as there is a growing number of patients who will not visit a dentist who is not a laser or holistic practitioner.
If a practitioner begins to learn on the bioesthetic or neuromuscular level, she will learn cosmetics while learning functional dentistry. However, if she is a current cosmetic dentist, the practitioner will enhance her understanding of the cosmetic/functional interrelationship of cosmetics. It does not matter where someone begins as long as she starts the process. What matters is that the patient is treated so that his or her overall dental health is benefited.
Quick functional/esthetic guidelines that should be met before cosmetic enhancement:
1. Looking at the face, use the index fingers as articulators to see how level the facial features are to the ears and thus to the ground. (Ideally, they should be parallel to the ground.)
• Are the eyes parallel to the ground?
• Is the maxilla parallel to the ground?
• Is the nose perpendicular to the eyes and to the maxilla?
2. Test the function.
• Can the patient open her jaw (teeth edge to edge) to a least three finger lengths (the patient's own fingers)?
• When opening and closing the mouth — is it smooth and is it a straight trajectory, or does the mandible deviate to one side?
• Is the shimbashi measurement greater than 17 mm? If it is less than 15 mm, the case cannot be done esthetically alone as the vertical dimension must be increased throughout.
3. Assess the body — is the overall posture good?
• Does the head sit squarely on the shoulders without slanting to the right or left and/or slanting forward, and does it sit on top of the spine?
• Are the shoulders parallel to the ground?
• Are the hips parallel to the ground?
If these conditions are easily met, then the practitioner can easily restore the patient strictly from an esthetic point of view (veneers), as the function is sufficiently intact to do so. If these criteria are far from being met, then the patient has to be restored bioesthetically and/or neuromuscularly — i.e., increasing the vertical dimension of the teeth and neutralizing any pathologic relationship between the teeth, arches, and jaws. If, for instance, the shimbashi is less than 17 mm (the ideal measurement is a zone of neuromuscular relaxation that is between 18 mm and 20 mm from CEJ to CEJ between the maxillary and mandibular teeth, depending on the width of the centrals), then the practitioner must obtain a transcranial X-ray and a sonogram to determine the health of the TM joints and a comprehensive bite analysis before proceeding with any dental work. This will ensure that the planned cosmetic work will be in agreement with the functional health of the patient.
In conclusion, we must remember that the success and longevity of the cosmetic case is ultimately determined by occlusal/muscular forces on the teeth and restorations. Cosmetic dentistry is ultimately about enhancing the quality of life for the patient, both physically and psychologically. By realizing that form follows the state of the functional system, we can see that cosmetic dentistry is really a kind of functional dentistry, and by combining the two, we really have a great working system on all levels for patient and dentist alike.