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The power of occlusal observation

dental occlusionHygienists can help pinpoint problems with occlusion

By Cathleen Terhune Alty, RDH, BA

"Observation: the action or process of observing something or someone carefully or in order to gain information."

In a rushed, fast-paced working day, how often do we take a moment to really observe our patients? Yes, we may perform all the perfunctory measurements and observe the condition of the gingival tissue, but patient care is more than looking for pockets, calculus, and bleeding points. Dental hygienists are in the perfect position to be functional observers, and can choose to include an occlusal evaluation as part of the hygiene examination.

This starts by using our powers of observation. Dr. Shereen Azer, associate professor at the College of Dentistry at Ohio State University, offers some guidelines for hygienists when evaluating overall oral function. He says that dental hygienists should consider hard and soft tissue health, esthetics, speech, chewing and swallowing, as well as a special emphasis on occlusion.

"In general," says Dr. Azer, "the dental hygienist should check the basic pattern of ‘normal' occlusal scheme, and that is simply to have the patient close down all the way to maximal intercuspal position (MIP). The aim is to locate contacts on all opposing teeth. Then from this position, the patient should move the mandible right and left to show ‘canine guidance,' which means ‘disclusion' of anterior and posterior teeth as the mandibular canine ‘rises' or ‘glides' onto the lingual surface of the maxillary canine. Similarly, as the patient moves the mandible forward in protrusion, the incisor teeth should provide disclusion of all posterior teeth. This is called ‘anterior' or ‘incisal guidance.'"

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Dr. Azer also suggests looking for wear facets on functional cusps. "Granted, wear is a normal process as a person grows older; however, we are looking for wear that is abnormal for age. For example, a noticeable generalized wear pattern of permanent teeth in a 30- or 40-year-old patient is ‘abnormal' for age, while the same picture might be ‘normal' for a 90-year-old."

Another important sign is bilateral palpation of the lateral pterygoid muscle. Dr. Azer says, "This is done by inserting the fingertip along the upper vestibule and reaching behind the maxillary tuberosity. That dead-end is the lateral pterygoid muscle. This muscle is responsible for opening and protrusion of the mandible, as well as side-to-side movements, particularly while chewing. If the muscle is tender or sore to the touch, this means that it is not being allowed to go to a state of rest due to ‘hyperactivity.' This is another powerful clinical indication of parafunctional activity going on, such as clenching or bruxism. Bringing these findings to the attention of the dentist is obviously important to check the cause, and many times prescription of a nightguard can ease that situation tremendously."

We can also discover more about how a patient's occlusion is functioning by listening to patient symptoms. Patients may complain of pain, jaw joint noises, or be completely unaware of clenching or bruxing. They might ask about whitening because of the dark yellow color on the incisal edges. They may mistake a deep cervical abrasion as a cavity. They may complain about waking up in the morning with headaches, a sore jaw, or achy teeth. They may complain about shifting or rotating teeth that just seem to move overnight. Patients don't understand the underlying pathology of these complaints and want a simple fix, when it may be an indication of something much more involved. The reason for their behavior may be traumatic occlusion.

Rochester, New York, periodontist Dr. Alessandro Geminiani offers clinical guidance in determining occlusal trauma. "Signs and symptoms of trauma from occlusion include tooth mobility, fremitus wear facets, widened periodontal ligament, hot/cold sensitivity, pain on percussion or pain on chewing, cervical noncarious lesions (abfractions), and tooth/root fracture."

Occlusal trauma and periodontal pocketing with bone loss are often seen together.

Connecting periodontal disease and occlusal trauma has proved elusive to researchers. Dr. Geminiani said, "There is a lack of scientific investigation assessing the percentage of population affected by trauma from occlusion. However, data extrapolated from a recent epidemiological study commissioned by the Centers for Disease Control (CDC) reported that 47.2% of the U.S. population is affected by periodontal disease. That is 64.7 million Americans over 30 years old! I feel comfortable saying that trauma from occlusion should at least be considered as a cofactor in the widespread epidemic of periodontal disease."

So can we further extrapolate that occlusal trauma may be another cause of periodontal disease? "Many researchers focused their investigations on answering this question," said Dr. Geminiani. "It is not easy to summarize almost a century of research, but here's my attempt. While in presence of excellent oral hygiene, trauma from occlusion per se does not initiate periodontal disease, but in presence of a plaque-infected dentition, trauma from occlusion accelerates progression of periodontal disease."

There are several treatment steps when trauma from occlusion is diagnosed. Dr. Azer says we typically assure a patient that there is a solution for every problem. "After the dentist has correctly arrived at a diagnosis and recommended treatment, the hygienist should follow up with the patient and give directions and home-care instructions," he said. "The hygienist should also evaluate the physical and functional conditions of existing prostheses or occlusal devices for signs of deterioration, wear, or breakdown, and share this information with the dentist."

Dr. Geminiani suggests that treatment starts with educating the patient in the etiology and pathogenesis of periodontal disease, as well as excellent plaque control. The second step is controlling the causes of occlusal trauma, which might include selective occlusal adjustment, orthodontic treatment, and/or prosthetic treatment. The third step is surgical and nonsurgical periodontal therapy. This may include a conservative approach, such as scaling and root planing, but also surgical therapy (including soft tissue grafts, bone grafts, and tissue engineering with growth factors) with the goals of reducing residual periodontal pockets and/or regenerating the periodontal support apparatus destroyed by periodontal disease and occlusal trauma. Last but not least is maintenance therapy. We know the importance of this crucial phase of therapy. Patients with periodontal disease and occlusal trauma should be on a strict recall schedule tailored to their needs, which is normally every three to four months.

Dr. Azer adds, "Traumatic occlusion is a very complex problem that needs careful diagnosis. The reason is that it is one of the important factors that causes temporomandibular disorders (TMD). The patient can enter into a vicious circle starting with pocketing and ending up with severe TMJ problems."

Proper occlusion plays an important role in maintaining a functionally healthy mouth. All of these signs and symptoms may or may not cause disease; a definitive diagnosis by a dentist trained in occlusal function is needed. By gathering our observations into a cohesive narrative for the patient record, we offer a better level of care to our patients, valuable clinical information to our doctor, and add an interesting challenge to our patient care examination.

During Hygiene Exam...

While many of these signs and symptoms are vague and can be associated with other diseases, fremitus is a clear sign of trauma from occlusion and could be assessed in just a few seconds during hygiene recall appointments. Dr. Alessandro Geminiani suggests placing an index finger on the buccal/facial surface of the teeth while in very gentle occlusion. At this point the patient is asked to close his/her teeth to tap and then clench. If movement of the teeth is detected, that is fremitus. It is a sign of premature occlusal contact on the teeth.

Hygienists can also look for loss of vertical dimension (looking at the space from the tip of the nose to the tip of the chin), thickening of the muscles used in mastication, chipped incisal edges or cusp tips, clicking or popping jaw joint hinges, and range of motion loss, either side to side or opening limitations.

Radiographic indications of occlusal trauma include a widened periodontal ligament space, flattened occlusal surfaces, isolated areas of vertical bone loss, tooth migration, radiolucencies in apex or tooth furcation, and changes in the appearance of the lamina dura (bone lining the tooth socket next to the PDL).

Cathleen Terhune Alty, RDH, is a frequent contributor who is based in King George, Va.

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