By James E. Carlson, DDS
Emotionally, physically, and spiritually, all humans live in varying states of ease or "dis-ease." The physical condition of humans is due partly to the head, neck, and face, which include the stomatognathic system. Traditionally, dentists have thought of this condition as ease or dis-ease of the teeth and gums. Still, many dentists overlook important segments of the stomatognathic system: neuromusculature of the head, neck, and face, temporomandibular, or TM, joints, and bones of the head and neck — all of which are part of the occlusion. Most general dentists don't provide customary examinations and diagnoses of patients' occlusal ease or disease, resulting in vast numbers of patients seeking and receiving dental care while they live with undiagnosed occlusal disease. Symptoms of occlusal disease include head, neck, and face pain emanating from muscles, pain and dysfunction in the TM joints, and many times by broken-down teeth. While dentists can see patients' broken-down teeth, often they do not "see" the muscles of the head, neck, and face, the disc-condyle complex of the TM joints, and the bones of the head and neck.
Why don't general dentists routinely examine the muscles, bones, and TM joints?
Historically, dentists focused on teeth. Avoiding and preventing tooth loss as a result of dental decay or periodontal disease is the major objective of dentistry. The muscles, bones, and TM joints often are ignored because most patients only seek care for tooth- and gum-related problems. They are not aware of occlusal disease. Also, most dentists are not trained to recognize occlusal disease. They don't pay much attention to it. Now dentists face fitting temporomandibular dysfunction, or TMD, pain patients into their practices and how to get paid for it. The insurance "morass" around TMD reimbursement affects dentists and patients. Reimbursement policies and procedures from insurance companies for TMD therapy are unlike those of standard dental insurance companies. In many cases, dealing with TMD insurance claims is a hassle. Dentists may work for insurance programs that do not pay for examinations, diagnoses, or treatment of occlusal disease.
It must make economic sense for dentists to invest their time and resources into learning about occlusal disease, and then to implement a new syntax of care into their "tooth-oriented practices." Patients whose occlusal disease is treated properly and whose pain goes away will be loyal patients for life and excellent referrals. Ignorance, embarrassment, not wanting the responsibility, reimbursement problems, or some other reason should not keep general dentists from learning about, diagnosing, and treating occlusal disease.
Much of what we learned about occlusion is inadequate. Occlusion may be more than you think. Interdigitation of teeth is not occlusion; it's only part of it. Occlusion is a dynamic, functional system designed for mastication, speaking, swallowing, and so on. It includes bones (skull, maxilla, mandible, and cervical vertebrae), muscles, nerves, and TM joints, as well as the interdigitation and spatial alignment of the teeth. The teeth are only a part. We cannot always see the whole because most of the parts are hidden under skin. Nonetheless, they are there, and they affect patients and treatment outcomes.
Stability of our finished dental cases depends on four elements: The Four Pillars of Occlusion.
They are the condition and alignment of the:
2); TM joints;
3) muscles and nerves of the stomatognathic system;
4) bones of the head and neck, starting with the maxillary complex and mandible, and including the rest of the skull and cervical vertebrae.
We must decide whether we will restore these Four Pillars of Occlusion to their previous condition or to a new, more stable ideal condition. We must expand our paradigm and look beyond the teeth and see the interrelationships of all the elements to create a better treatment outcome for our patients than what we have done in the past.
Before we can discuss occlusal disease we must first look at occlusal ease. "Ease" can be defined as a normal condition of physiological function of an organism or part. "Dis-ease" is defined as an abnormal condition of an organism or part, especially as a consequence of infection, inherent weakness, or environmental stress that impairs normal physiological function. To identify a disease, the clinician must first recognize what ease looks like. Ideally, the clinician should recognize disease by knowing the characteristics of normal physiology and anatomy. To define occlusion, dentists need physiological and anatomical benchmarks for the muscles, teeth, bones, and TM joints. These occlusal benchmarks are necessary for dentists and patients. Patients want to know the state of their occlusal health compared to what is considered optimal. Also, how can dentists diagnose and determine optimum treatment plans if they do not know what normal or optimal occlusion looks like? If dentists choose to treat occlusal disease, the goal should be to help patients return muscles, teeth, bones, and TM joints to states of ease.
Benchmarks of occlusion
The following is a partial list of benchmarks used to help dentists examine, diagnosis, and treat occlusal disease.
‡ Healthy muscles are pain-free and should not exhibit pain or trigger-point referral patterns when palpated with moderate pressure.
‡ Healthy TM joints are quiet during the mandibular open/close cycle and should not make popping, clicking, or grating noises or emanate vibrations.
‡ The mandible should open and close straight, without deviation or deflection.
‡ The mandible should have an interincisal distance of 45 millimeters to 55 millimeters at maximum opening.
‡ The plane of occlusion should be level and parallel to the horizontal reference plane of the skull.
‡ The plane of occlusion should be at right angles to the sum of the forces of occlusion, created by paired muscles of mastication on each side of the face.
‡ The plane of occlusion should have an ideal curve of Wilson and curve of Spee unique to that patient.
‡ Posterior teeth should interdigitate with cusp-tip-to-fossa occlusion.
‡ Anterior teeth should have an optimum overbite/overjet relationship unique to that patient.
‡ All posterior teeth should exhibit centric stops.
The interdigitation of the teeth at an optimal mandibular position should support a physiologic neuromuscular position and physiologic position of the disc-condyle complex in the TM joints for which the nervous energy supplied to the muscles is at a minimum.
Occlusal examination and diagnosis
To treat occlusal disease, clinicians must first examine and diagnose patients. That may not be as easy as it sounds. Patients of all ages have occlusal disease, but most often it goes undetected. This is especially true in adolescents. They may be victims of occlusal disease exhibited as headaches, migraines, neck aches, earaches, and sinus and facial pain, but they do not understand that the pain is related to their occlusion and it may be diagnosed and treated by their dentists. Neither children nor their parents see a connection between the pain and a dentist. Some symptoms of occlusal disease are passed off as normal "growing pains," and children needlessly suffer because of their parents' and dentists' ignorance. This, in part, is a fault of dentistry because dentists rarely learn to look for occlusal disease in children except those arising from teeth and gums. Blame should not be put on parents. It is dentists' responsibility to educate parents of the possibility that some of their children's pain may be from muscles of the head, neck, face, and TM joints.
Adults also dismiss head, neck, and face pain from dental origins as part of normal living. Many cope by taking over-the-counter pain medication. No matter what the age, it is not normal to have pain in the head, neck, face, and TM joints. Early detection of TM joint dysfunction and myofascial pain from the head, neck, and face should be part of general dentists' services. This requires a new paradigm of occlusal examinations and diagnoses. Times have changed, and progress has been made in occlusal examinations, diagnoses, and treatment techniques. New and better methods and instrumentation are available to help examine, diagnose, and treat patients with occlusal disease than have been available in the past. With this awareness comes responsibility. No other health care provider is responsible or trained to examine, diagnose, or treat occlusal disease. Patients have the pain. General dentists should be trained to find the causes and treat them, not mask the causes and treat the symptoms.
It does not take much time to screen patients for occlusal disease. Palpating a few key muscles, examining the teeth for attrition, wear facets, and abfractions, palpating the TM joints for pain and swelling, listening for noises, and feeling for joint vibrations are just a few procedures in screening patients for occlusal disease. If screenings show positive signs of occlusal disease, patients should be appointed for occlusal examinations of the teeth, muscles, TM joints, and bony structures of the head, neck, and face.
To begin learning to examine, diagnose, and subsequently treat these pains and dysfunctions, dentists must have basic understandings of anatomy and physiology of the muscles, TM joints, bones of the skull and cervical spine, and alignment of the teeth. That means taking postgraduate courses to learn what is physiologic occlusion, recognize what is not ideal, make the diagnosis, and inform the patient of what the dentist sees. If patients choose to be treated, either learn how to take care of them or refer them to someone who can.