Dental Compression Syndrome and TMD

Dental Compression Syndrome and TMD

compression in tips of functional cusps

Temporomandibular disorder (TMD) is not just one disorder, but a group of conditions that painfully affect the temporomandibular joint (TMJ) and the muscles of mastication. The ADA estimates that 10 to 14 million Americans have TMJ disorders; 80% of these are women between 24 and 50 years of age.

Dental Compression Syndrome (DCS) is a contemporary name for the age-old condition of grinding and/or clenching of teeth. Capable of generating forces in excess of 500 pounds per square inch, DCS simultaneously applies pressure to the dentition, alveolar bone, and the TMJ.

compression in gingival area

WHAT IS THEIR RELATIONSHIP

Although it is generally understood that TMD may have a variety of causes, such as a severe injury to the mandible, arthritis, teeth not fitting together correctly, and structural abnormalities, it is generally believed that the majority of TMJ disorders, now of epidemic proportions, is simply due to repetitive motion trauma from DCS. Since 1990 scores of published articles associate DCS with TMD. The implications are that since there is such a strong relationship between DCS and TMD, if a patient with TMD exhibits signs of DCS, the focus of treatment should be directed toward managing DCS in order to reduce stress on the TMJ. The purpose of this article is to review the etiology, signs, and management of DCS.

DENTAL COMPRESSION SYNDROME: UNDERSTANDING AN OLD PROBLEM

The flattened dentition of our ancestors tells us that DCS has been epidemic throughout the ages. What causes it? There is no doubt that life stress causes a majority of people to clench and grind their teeth, but other factors have to be considered when consulting with the patient.

ETIOLOGY OF DCS

Exercise/sports: rowing, water skiing, lifting weights, boxing, riding a motorcycle, or any sport where there is a bracing of the body.

Psychological: anxiety, fear, tension, pleasure, aggression, anger, dreaming, stress.

Medical: sleep apnea, oral pain, or pain in other parts of the body.

Drugs: caffeine, amphetamines, cocaine, ecstasy, fluoxetine, fluvoxamine, paroxetine, sertraline, haloperidol, and venlafaxine.

Bioengineering factors: DCS can be easily initiated by a violation of bioengineering principles in the stomatognathic system, such as prematurities, off-loading of teeth, horizontal distraction of the mandible upon closure, and misalignment of the TMJ components.

DIAGNOSIS

One reason DCS has been so successful over the centuries is that it works well within one’s subconscious.

Since few patients affected with DCS are cognizant of it, it is imperative that the visual signs of compression be recognized so that the problem can be addressed. Besides the obvious signs of a flattened dentition and hypertrophied muscles of mastication, certain deformations appear in the oral environment whose causes or significance are barely recognized. They affect the dentition, bone, and restorative materials.

Management of Parafunction

The presence of deformations in the oral environment should stimulate a dialogue to determine if the patient is currently grinding and/or clenching his or her teeth, or whether this damage occurred during a prior stressful period in his or her life. Often a patient will deny any awareness of DCS, but upon returning will say something like, “You know, since you brought it to my attention, I catch myself all the time.” Management of DCS begins with awareness and proceeds with a 3-step treatment plan that consists of education, equilibration, and guard therapy.

Step 1: Education

The dental healthcare provider must educate the patient about DCS in the simplest terms. Patients need to understand that teeth should only touch upon swallowing, and should know the resting position of the mandible (lips together, teeth apart). The list of etiological agents should be reviewed. Patients should be asked to monitor their jaw position during waking hours and be sensitive to headaches and tension in muscles of mastication upon waking. If it is obvious that the patient is affected with DCS and is indifferent to the problem, then his or her dental records should indicate such and no further treatment should be initiated. However, if the patient is aware of and wants to eliminate or reduce the problem, the next step would be to analyze the occlusion in order to determine if the morphology of certain teeth needs to be modified.

Step 2: Equilibration

In order to determine the need for an equilibration, the patient’s present occlusion must be compared to a standard of excellence, ie, ideal occlusion. Based upon nature’s original design, the most ideal occlusion is where the occlusal contact is confined to the tip of the functional cusp. There are 2 noteworthy observations. One is the minimal contact confined to the tip of the functional cusp, and the other is the generous space between the incline planes of the cusps, termed the intra-incline space.11 From these observations it is interesting to note that teeth do not require large areas of contact in order to maintain their position, work efficiently, and be comfortable. But what was nature’s intention in providing such clearance between the incline planes? From an engineering point of view, there are several advantages:

Vertical loading . 

The intraincline space (between the incline planes) ensures vertical loading. Misch and Bidez describe vertical compression forces as normal and explain that they act perpendicular to and maintain the integrity of the alveolar bone.

Neutralization . 

This is the desired buccal-lingual position of the tooth by reciprocal action of the muscles of the tongue and cheek. When the incline planes do not touch, the tooth is free to assume a neutral position.

Methods of Equilibration Indirect Method:

• Reposition condyles.

• Mount models on 3-dimensional articulator.

• Adjust occlusion on models.

• Repeat with natural dentition.

Disadvantages: time consuming and expensive; not as accurate as direct method.

Direct Method:

• Utilizes patient’s own stomatognathic system as a biological articulator.

• Occlusal indicator wax demonstrates contacts in closure.

• Areas of displaced wax are analyzed.

• Contacts on incline planes are eliminated.

Advantages: more accurate; less time; inexpensive; easy to facilitate.

An equilibration is a reduction of the working cusp inclines. For easy patient understanding it is suggested that the procedure be described as “a sharpening of functional cusps.” Terms like equilibration and coronoplasty are too formal and require further definition. The patient needs to be informed that the teeth are never shortened, and the benefits (increased comfort and diminished DCS) will far outweigh the conservative loss of enamel. The entire procedure should take no longer than 15 to 20 minutes. The patient should be seen in a week or two for final analysis and polishing. Informed consent must take place. We have been cautioned against imposing occlusal changes based upon the clinician’s concept of the ideal.30 However, it is correct to reshape worn, deformed teeth in order to regain their original configuration with intra-incline space. A review of 15 articles on occlusal equilibrations published in professional journals reveals generalized agreement on the following points:-

•  Prophylactic adjustments in the absence of pathology are not acceptable.

• Occlusal adjustment is a misunderstood and an underutilized procedure.

• CR should equal CO.

• There should be no interferences in lateral excursions.

• The height of the buccal cusps should never be shortened except to eliminate interference in lateral excursions.

• Traumatic occlusal relationships should be eliminated before restorative procedures.

• Cusps should touch loosely in the opposing fossae.

• Inclined planes should not touch to ensure axial loading.

• Occlusal indicator wax is the most effective way to demonstrate how teeth touch.

• There should be no flat-plane occlusion in humans.

• Cuspid guided occlusion is preferred.

A recent publication confirms the relationship between equilibration and gingival fatigue. This 17-year study evaluated the relationship between gingival fatigue due to DCS and its relief by sharpening the functional cusps.46 Over a 17-year span, 246 teeth were verified as having hypersensitivity from gingival fatigue, which was resolved by equilibration in 2 visits. The study confirmed that the equilibration specifically involved reduction of the working cusp inclines, and that it significantly reduced cervical dental hypersensitivity.

Step 3: Occlusal Guards

Proper management of the patient who is affected with DCS entails addressing the problem on 3 separate levels. The sharpening procedure satisfies the engineering requirement, and educating the patient can certainly help in stress management during waking hours. But only a guard can ensure protection while sleeping.

 But what kind—hard, soft, full-arch, anterior?

Unfortunately, there are conflicting studies.  Which is best? Again, we have to evaluate our objectives from an engineering point of view.

If our goal is to diminish the force on the TMJ and reduce muscle tension, then the best design is a small, thin, hard acrylic appliance that covers the lingual surfaces of the maxillary anterior teeth. It is often referred to as a deprogrammer or mandibular repositioner. A common question regarding this design is, “Do the posterior teeth supererupt?” No, it is not like the Hawley retainer that is worn a majority of the time.