The Joint Protective Stabilization Appliance
The Portland TMJ Clinic's joint protective stabilization appliance is a simple and effective way to provide rapid symptom relief when there is inflammation present in a TMJ. The appliance fits over all the upper teeth and contacts all the lower teeth on a bite surface that has been sculpted to protect the inflamed TMJ during the large biting forces that affect everyone in nocturnal bruxism (clenching and grinding during sleep). In this manner, the appliance acts like a brace to protect the injured TMJ during its workout, much like a brace to protect an injured knee during sports. The first couple of nights of wear should eliminate all the pain and inflammation, and two months of wear should ensure that the damaged TMJ has healed (anatomical adaptation) and functions like a normal TMJ. Subsequently, your TMJ will no longer need protection, and your joint protective stabilization appliance can be converted into a muscle treatment and long term growth appliance to prevent the problem from returning. To make the appliance comfortable, we make it as thin as possible and give it a passive fit. To promote healthy tongue posture, we carve out an area just under the bite table in the front of the palate to fit the tip of the tongue (tongue tip hollow).
NIGHTGUARDS, made by almost all general dentists, are designed to protect the teeth from wear by interposing a layer of plastic between them. When a relatively soft material (plastic) is placed between two harder materials (teeth), all wear occurs on the softer material. However, excessive wear of teeth rarely causes TMJ disorders, because teeth are made for wear. Teeth with wear are healthier than teeth without wear. Nightguards are not designed to protect the TMJs or treat the jaw muscles, so their effect on a TMJ disorder is random. They could make it better, they could make it worse, or they could have no effect on it.
COMMON STABILIZATION APPLIANCES, made by most TMJ dentists, contact the teeth more evenly than simple nightguards, which helps relax the jaw muscles, but they are still not designed to protect the TMJs. Instead, their contours reproduce those of a natural bite at an increased height, with canine guidance in front and relatively flat contacts in back. The increased stability can reduce muscle tonus, and the height can stretch the jaw closing muscles; but their main orthopedic effect is just propping the jaw open. If the symptoms are due to overclosure of the jaw, (usually from old dentures or severely worn down teeth), this orthopedic "lift" can provide significant relief. However few TMJ disorders are due to overclosure.
OUR JOINT PROTECTIVE STABILIZATION APPLIANCES - have a bite surface that has been orthopedically sculpted to protect the inflamed TMJ by preventing the condyle from accessing its bruised retrodiskal area. The retrodiskal tissues are very vascular, because they were designed to supply circulation to the metabolically active TMJs. When dragged into the joint space by dislocation of the disk, they acquire all the characteristics of a chronic bruise - with blood leaking out of vessels, swelling, heat, and pain. Joint protective appliances protect the bruised retrodiskal area by means of anti-retrusive ramps, usually located just behind the upper front teeth, like shown below.
Below the top illustration shows the manidible fully seated in the therapeutic bite position. The bottom illustration shows an anti-retrusive ramp just beginning to engage the front teeth as the patient closes into the appliance. Further closing will slide the mandible forward away from the inflamed TMJ.
Anti-retrusion ramps are also occasionally located behind the molars or around missing teeth if there is space available. The optimal location of the ramps for each patient depends on the direction of the TMJ dislocation, the disk shape, and the condition of the teeth.
The angle of the anti‐retrusive ramps determines the degree of TMJ protection they provide. Shallow ramps are used when inflammation is minor and the symptoms are more muscular, because muscles benefit from freedom of movement. Steep ramps are used when more TMJ protection is needed, such as when a TMJ is acutely inflamed. Correctly designed anti-retrusive ramps should enable you to clench forcefully in any jaw position without experiencing the pain that you experience when you clench forcefully against your natural teeth. If the damaged TMJ requires more joint protection than the anti-retrusive ramps can provide, you'll need a telescopic (Herbst) appliance.
PIVOTING can be added to the appliance over the last molar on the side of the inflamed TMJ to provide quick temporary relief. The pivot is a little high spot that is located behind the line of force of the jaw closing muscles, where biting forcefully on it distracts the condyle from the inflamed TMJ. The relief of pain from biting on the pivot should be immediate, but a pivot can put a lot of pressure on the teeth bearing it or striking it, so it is only a short-term measure.
For the first day or two, it may feel good to wear your appliance on and off during the day; but after that you should only need to wear it at night to prevent the inflammation from returning. You'll know there is no inflammation, because you can clench with full force for three seconds anytime day or night, whether or not you are wearing the appliance, without experiencing any increases in pain during the clench. Pain after the clench would be muscular. Adjusting the appliance should not be needed if it is made correctly. Small improvements to its stability occur anyway during the first week due to the hard teeth digging into the softer plastic.
CONVERTING TO A LONG-TERM USE APPLIANCE – After the damaged TMJ has not been inflamed for at least two months, it should no longer need protection, and it can be converted into an oral appliance that treats your jaw muscles and improves your facial growth pattern in a manner that moves you away from the strain that caused the problem in the first place. The orthopedics that you need for long term health depends on your facial growth pattern and the state of your teeth. Your jaw muscles may need stretching or strengthening. Additional orthopedic features can be added to promote horizontal facial growth in a manner that reduces resistance to airway flow and/or eliminates growth restrictions.
FLAT BITE PLATE APPLIANCES allow the mandible a full range of motion, which promotes muscle health, because they like long smooth strokes. Also, front flat bite plate appliances gradually and steadily reduce restrictive overbites, often the original cause of the problem. Full arch flat bite plate appliances are preferred in people who have little or no overbite. The conversion to a flat plate appliance can be made during one appointment using our in-house dental laboratory for $300.
PALATE EXPANSION APPLIANCES may be needed to improve nasal airway flow and make room for crowded teeth. The conversion to a palate expansion appliance requires a week and a substantial lab fee. Wires, springs, buttons, and elastics can be added if needed to straighten individual teeth.