CR--Time Tested Ignorance!
Clayton A. Chan, DDS
July 7, 2000
The traditional mind set of occlusal teaching has pervaded our profession since 1864 when W.G.A. Bonwill first recognized that the condyles often moved away from the position they occupied during hinge closure. The long historical record of dental pioneers have consistently used the bio-mechanical approach to articulation, occlusion and mandibular movements, with a limited understanding to muscle physiology and neuro-physiologic science. These musculoskeletal, anatomical as well as bio-physiologic aspects of condyle to glenoid fossa position, mandibular movements and occlusion has been the focus of interest among forwarding thinking practitioners, dental scientists and academians who have been striving to understand how best to develop a stable and physiologic occlusion in these past thirty years. The neuromuscular concepts to occlusion have stirred traditional thinking to the present day. Those that are not open to learn will continue to believe, without intellectual for-thought, that their sacred centric relation, "CR" position is the answer to all.
If you pin point what the believers mean by CR, they will define CR based on what their present occlusion leader told them. Many of the leaders themselves cannot agree on this man-made manipulated acquired position since there are 26 definitions of CR. Seven of them are in the Prosthetic Glossary of Terms with varying interpretations from differing dental organizations. It is easy to say that the problems a patient is having is because "they are not in CR". Those words come so easily out of their mouths as a mantra, without realizing what they are saying. "They are not in CR .... It is time tested". Where is CR? Is it anatomic, physiologic or even scientific? Where is the evidence, the scientific proof, to support such a "time tested" premise.
Musculoskeletal Occlusal Signs and Symptoms
Since the present day occlusal philosophy has focused mainly on the mechanical aspects of treatment, tradition has neglected to see the fine nuances and inter-relationships of many musculoskeletal occlusal signs and symptoms that effect the complete anatomic and biological system. The biological interactions of the musculoskeletal system with the various functioning components are often not considered in a scientific bio-physiologic model. The CR mentality has a limited understanding to the following list of occlusal signs and symptoms, thus the traditional thinkers assume their patients are comfortable and OK.
It is obvious that the CR philosophy and the neuromuscular philosophy of occlusion may use the same language and terms, but may interpret their observations at a very different level of understanding. Think about the following list and their relationships to occlusion, patient comfort, and how it impacts the dentistry that is diagnosed and treated. Often these symptoms are not considered in the overall treatment plan and may be overlooked without realizing the long-term impact it may have on our patient's dental and medical health. They may be often ignored since many of these symptoms present themselves as medical oriented symptoms, yet with dental implications. We often think that these medical symptoms do not deal with our traditional paradigm of occlusion and mechanical approach to dentistry (tooth care).
In the neuromuscular dentist training we advocate firstly, that the doctor should start by developing better diagnostic skills and enhanced understanding, thus becoming better aware how the physiologic phenomenon impacts the cranium to jaw relationships, mandibular position, the temporomandibular joint position and dental occlusion. The neuromuscular dentist soon realizes how these occlusal signs and symptoms impact treatment and at what level of treatment they should begin.
Neuromuscular Dentistry is all about making doctors become aware of physiologic responses and confirming our patient's perceptions.
Musculo-skeltal Occlusal Signs and Symptoms
Symptoms:
- Headaches
- TMJ pain
- TMJ noise
- Ear congestion
- Limited opening
- Vertigo (dizziness)
- Tinnitus (ringing in the ears)
- Dysphagia (difficulty swallowing)
- Loose teeth
- Clenching/ bruxing
- Facial pain (non-specific)
- Difficulty chewing
- Tender, sensitive teeth
- Cervical pain
- Postural problems
- Paresthesia of fingertips (tingling)
- Thermal sensitivity (hot and cold)
- Trigeminal neuralgia
- Bell's Palsy
- Nervousness/ insomnia
Intra Oral Signs:
- Crowding lower anteriors
- Wear of lower anterior teeth
- Lingual inclination of lower anterior
- Lingual inclination of upper anterior
- Bicuspid drop-off
- Depressed cure of Spee
- Lingually tipped lower posteriors
- Narrow mandibular arch
- High vaulted palate
- Midline discrepancy
- Malrelated dental arches
- Tooth mobility
- Flared upper anterior teeth
- Facets
- Cervical erosion
- Locked upper buccal cusps
- Fractured cusps
- Chipped anterior teeth
- Loss of molars
- Open interproximal contacts
- Unexplained gingival inflammation and hypertrophy
- Crossbite
- Anterior open bite
- Anterior tongue thrust
- Lateral tongue thrust
- Scalloping of lateral border of tongue
When thoughtful consideration is applied to each symptom and occlusal sign in relationship to the functioning occlusion, the surrounding hard structures, tissues and ligaments of the stomatognathic system, it becomes apparent that the CR relation concept takes on a diminished level of importance. One soon realizes, for example, when taking the neuromuscular occlusal perspective, that the implications of a high vaulted palate impacting a patients breathing capacity will naturally infringe on the upper turbinates, thus restricting proper breathing habits, increasing potential for sinus problems, allergies, perpetuate abnormal tongue posture, abnormal mandibular posture, as well as resulting malocclusions (deep overbites).
With mouth breathing one may develop a sluggish waking pattern in the morning, less oxygen to the brain with diminished alertness. Puffy gums periodontally can result even though the patient has meticulous home care due to compromised mouth breathing patterns also resulting in hypo-calcification (white spots) of tooth structure. A forward head posture may result, with compromised shoulder posture and neck aches symptoms. Malocclusion problems and seemingly un-curable teeth sensitivities can continue to haunt the patient and the professional for years. More dentistry is advocated, addressing often the symptoms to cure the problem to only continue the perpetual cycle of further dental procedures and treatment, rather than addressing the source of the problem and identifying the cause. Dentistry is further done in the present malocclusion (narrow arches, mouth breathing problems, class II molar relationships) even with bicuspid drop-off (depressed curve of Spee), deep over lap and over jet of the anterior teeth with the further evolution of unstable occlusion and abnormal posturing of the mandible to cranium relationships.
Facial form is changed with retruded mandibles and a deep mentalis fold often ignored and never realized of the subtle impact in has on the life and health of the patients dentition. Abnormalities thus become the norm. Muscles are strained, smiles and arch shapes are compromised. The patient are unconsciously led to believe that these factors are due to the aging process of getting older and more "stressed". Many may believe that this is how the patient is genetically designed. We come to believe in a mechanical frame of thinking as normal. Our model for normal is actually sick, compromised function and unhealthy. What becomes common then becomes the norm. We then have difficulty distinguishing between what is normal from abnormal, what is healthy versus unhealthy, dysfunctional versus functional.
Not Accepting the Norm
The neuromuscular dentist does not accept the norm. He goes beyond the mechanical paradigms and uses objective means to measure and record physiological and anatomical phenomenon to support his/ her basis for a particular mode of treatment. He or she brings a wide range of disciplines to enhance their treatment effectiveness and outcomes to their patients from the many facets of dentistry and bio-physiologic and anatomical sciences using objective means to bring a rational understanding to what has been observed or reported. It is often due to our traditional training and dental environment that our medical and dental awareness is hindered to seeing the bigger picture of complete dental care. Many of these occlusal signs and symptoms can be identified, prevented and treated. More prescription drugs and medications is not the answer to chronic allergies, sinus problems, headaches and muscular dysfunctions.
Do those of the traditional CR thinking concept understand and realize these bio-physiological factors that impact the dental and medical health of our patients? They have no problem in performing the dentistry from the mechanical perspective since the standard of care allows it to be so. I would challenge any doctor who is treating TMD/ facial pain problem cases in a mechanical CR mode to see the difference in outcomes when taking a functional bio-physiologic perspective. It is obvious that most experts in the field of TMD/ myofascial pain and orthopedics do not treat this way. Especially if the patient has severe TM Joint pathology. Placing ones condyles in CR with osteodegenerative changes of the condyles is sure doomed for failure and frustration. In what position should the condyles be positioned when helping these type of dysfunctional jaw joint paining patients. In CR? Many TMD / occlusally compromised type patients have problems they are not even aware of, let alone the unsuspecting dentist. Sure they have had their mouths rehabilitated in CR, with induced occlusion. But the traditional CR teachings fail to recognize that these symptoms can be related. They often assume it was a psychogenic cause, especially when the mechanical model does not present with an answer. Thus the continuance of a referral and seeking for answers on the part of the chronic paining patient.
Diagnosis and Treatment is Rendered Best by Measuring
Many of the practitioners are used to focus on looking at the teeth, gums and joints from their colored perspective independent of one another. Let us think outside the box and realize that these functioning components are interrelated and function together. The teeth, the muscles and joints are connected to the same bone, the mandible. Adjustments can be made by equilibration techniques to adjust and make the teeth fit seemingly perfectly together, yet ignore the pathologic joints that are strained and torqued in the glenoid fossa resulting in future disharmony and accommodated compensations to other bodily structures when overlooking muscle physiology.
One can only diagnose and treat what one sees and is aware of. It is like looking at gum tissue without pocket probing. One can best access periodontal health by measuring pocket depths if one wants to know the health of the periodontium. Sure the gums look firm and pink, but you will not know for certain unless one measures! It is the same with the jaw joints, mandibular position, and occlusion. We can measure muscle function and status during function and at physiologic rest via EMG. One can measure mandibular moment and distinguish abnormal mandibular opening patterns from abnormal patterns via mandibular jaw tracking. Velocity tracings can be objectively be recorded to observed bradykinesia and dyskinesia in mandibular movements. The neuromuscular dentist can verify with technology the physiological responses that are often unseen through common radiographs and visual analysis of the TMJ via sonography. That is if one wants to. Treatment recommendations and long-term outcomes will be different for those patient lives when measurements and objective data are taken and analysed.
CR is time tested ignorance!
It is obvious that there are some who choose to only see what they want to see. If one wants to see mounted study casts plastered to an assumed accurate position on an articulator that actually hinges, then that is OK. What about capturing a more physiologic maxillary to mandibular arch relationship by means of neuromuscular technology and consider muscle physiology at an optimal rest? What about decompressing the joints and arriving at an occlusal relationship that harmonizes with the physiologic functioning of the complete posturing system. Let us not forget to be physicians of the stomatognathic system as well as scientist, rather then only being tooth doctors. There is a place for that kind of dentistry too, since those that enjoy it do perform a service along the hierarchy of the dental/ medical health care chain. Those that don't get the help will eventually seek the care and service from those that understand these musculoskeletal signs and symptoms. It is just more dentistry for those that go beyond the traditional paradigm. We will never go hungry! We don't have to worry about trying to find dentistry, it is there if we are aware of it.
Taking this approach and perspective is very comprehensive. Maybe more comprehensive than some doctors really want to accept or are willing to learn. Consider the Neuromuscular Approach to Comprehensive Care and step into a world that is vast and exciting.
Clayton
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