by Clayton A. Chan, D.D.S., M.I.C.C.M.O

Equilibration (Occlusal Equilibration)
Equilibration is a technique used to gain an even bite in a habitual or centric related position. Teeth, fillings or crown restorations are typically adjusted by the dentist. These type of occlusal adjustments are done with a high or low speed handpiece (“drill”) to remove any bite contacts that are prematurily contacting during jaw closure. The equilibration technique does not necessarily consider cusp to fossa relationships, but rather its focus is to develop an even bite in an accommodated habitual position. It is prudent to recognize the musculoskeletal occlusal signs and symptoms prior to having this procedure performed by your dentist. The vertical health of the jaw, the antero-posterior health of the mandible as well as the lateral health of the mandible and joints are not necessarily considered by all dentist as key factors when relating the support and overall physiologic health of the cranio-mandibular cervical posture, especially when perform this take away procedure among most dentists.

Your Bite Is Important – Don’t let any dentist take it from you.

“Equilibration is a valid occlusal procedure only when used with normalized temporomandibular joints and when masticatory muscles are in a state of normal tonus at their resting lengths except during periods of function. Equilibration should only be performed at the end of stage II finishing procedures, i.e., when the restorative or orthodontic treatment is completed. To do equilibration procedures prior to this is inappropriate since this adapts the occlusion to temporomandibular joint pathology or dysfunction.”

Brendan C. Stack, DDS, MS
Grummons, D.: Orthodontics for the TMJ/TMD Patient, Wright and Co. Publishers, Scottsdale, AZ.,1994

WHEN TO GRIND and WHEN EQUILIBRATION IS ACCEPTABLE

• When the patient is not experiencing any masticatory pain or discomfort. (This means, no tender muscles of the temples, facial muscles, lower jaw muscles and shoulder muscles, prior to any dental procedure).
• When there exists a solid stable habitual bite and routine single tooth dentistry is performed and the dentist needs to adjust the new filling or crown only into position.
• When there is no clicking or popping of the jaw joints prior to any dental procedures. (Patient’s and dentist should be aware of this)!
• When there is sufficient vertical height and dimension of tooth structure available.
• When there is sufficient enamel to adjust.
• When a single tooth is hitting or contacting prematurely and is sensitive or having tooth pain.
• When it has been recognized that jaw joint degeneration does not exist. (No clicking sounds, grating sounds (crepitus) exists).

WHEN NOT TO GRIND or EQUILIBRATE the TEETH

• When the patient reports or experiences tender masticatory muscles or pain.
• When there is jaw joint pain (Intra capsular or extra capsular)
• When there is existing jaw joint degeneration (Tomographic, MRI or cone beam imaging can confirm).
• When there is clicking and popping sounds (crepitus) during opening and closing of the jaw (this indicates that the jaw/occlusion is not stable).
• If there is a previous history of jaw’s locking opened or closed. (This usually is an indication that there is a condylar disc problem).
• If the person has had an extensive amount of restorative dentistry performed, adjusting or equlibrating the bite will often lead to further occlusal problems (unless the dentist is extremely skilled and understand the consequences and treatment outcomes.
• When there is lack of posterior vertical dimension of occlusion.
• When there exists airway obstruction and breathing problems.

Most equilibrations (tooth grinding) procedures are performed in a laying or supine position. This is not natural. Gravity plays a significant role in how the mandible moves and functions. Muscles of the jaw always seeks a neutral position or relationship and want to be supported by a comfortable bite when sitting up in an upright position. Be very cautious to have any dentist adjust or change your bite unless a consultation and examination is performed and a thorough diagnosis and treatment plan calls to do so. Equilibrating a bite to establish a balanced bite is very note worthy and noble, but it is imperative that the dentist must have hand skills, a thorough knowledge of muscle physiology, cervical neck and head posture understanding as well as comprehend the dynamics and condition of the patients temporomandibular joints prior to performing equilibration techniques. Remember it is a take away process (irreversible procedure). Removing unwanted occlusal inteferences must be done in a manner that satisfies the physiology of the musculature of the mandible to the cranium and musculature of the cervical/ neck and head region.

Typically, removing tooth structure to establish an even bite should be a rare and uncommon procedure within the dental profession since most patients who come for dental care often have an uneven accommodated bite with clicking and popping joints, grating joints, chronic unresolved shoulder aches, facial pain, jaw joint pain, headaches, neck aches, ear congestion or fullness in the ears feelings amongst a list of musculoskeletal occlusal problems. If equilibration is performed properly on patients who do not present with an over closed bite (deep bite, or retruded bites) the equilibration process can be very helpful. If the patient has existing TMJ problems or has an imbalanced atlas (C1, C2), imbalanced occiput and/ or imbalance pelvis (sacrum/iliac) equilibration procedures should not be causually done, especially on natural dentition or restored mouths that have insufficient vertical dimension of occlusion.

Patients with deficient vertical and worn dentition should consider having dental procedures that add back to the loss of vertical dimension (to restore the lost height of teeth) rather than further removing more tooth structure that can reduce the vertical height of your posterior teeth and cause one to loose a physiologic opening and closing path of the jaw (neuromuscular trajectory).

Classical equililibration techniques when done in a supine (laying down) position, even with the most skilled hands, can result in:

• The patient feeling that their front teeth are hitting stronger or more firm than the back posterior teeth.
• Pressure on the upper front teeth.
• Increased temporal headaches and neck aches.
• Tooth mobility
• Increased tooth sensitivity.
• Increased ear congestion feelings (stuffy ears).
• Ringing in the ears
• Vertigo

Follow up visits may be required to adjust out those occlusal prematurities that are determined to be hitting on the upper lingual surfaces or lower labial surfaces of the anterior teeth while the patient is sitting up. Although these techniques have been around for as long as dentistry has been around, it is at best an subjective means to balance the teeth with no measurable accounting as to what it is doing to the surrounding musculature. If the patient has a high level of accommodatative capacity (tolerance) the equilibration process may help improve the bite and occlusal balance. If the patient has a very narrow accommodation (tolerance) to these changes as seemingly small as they may be, they can contribute to devistating challenges, that are not easily or inexpensively remedied.

All patients must be aware that the most dentist who are performing the classic equilibration procedure to give you and even “balanced bite” do not measure or quantify before hand how much tooth structure they are planning to grind away, except by eye balling the process. Remember, this is your teeth and your bite that you are use to feeling, swallow, use daily and chew your food. Your comfort and stability of your occlusion is crucial to your well-being. One single micro change or alteration to the way the teeth come together even if the equilibration was done on a single tooth surface can cause a cascading domino effect on your bite that will be difficult for any person and trained dentist to return to your bite back to the original condition, if not impossible.

Check with your dentist and inquiry if equilibration is really approprioate and necessary for your particular situation.

© 2009 Clayton A. Chan, DDS. All Rights Reserved.

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