MIGRAINE HEADACHE PREVENTION WITH THE NTI ORAL APPLIANCE

from the library of Robert L. Talley, DDS.

Migraine headache prevention is intended to reduce the suffering and disability associated with attacks. One method of prevention involves using a dental device to help reduce the intensity and the amount of jaw muscle activity. To understand how the jaw can influence migraine pain, we need first to review what is known about the mechanisms responsible for migraine headache.

Most people with migraine were born with a sensitive nervous system that overreacts to internal changes such as poor sleep or fluctuations in hormone levels or to external triggers like strong odors or perfume. The combinations of factors that cause the headache are often different for each headache. The same combination of events may cause headaches on some days and not on others. This variation is due to changes in the body’s resistance to these triggering factors. This resistance may be strong on one day and weak on another.

The point at which the triggering factors overwhelm the body’s resistance is called the migraine threshold. The migraine threshold in headache-prone individuals depends on the complex balance between impulses that stimulate or inhibit a specific area in the brainstem located at the base of the brain above the spine. The brainstem has many complex roles in regulating the body’s response to the environment. It also contains the trigeminal nucleus, which is the central processing area of the trigeminal nerve, that supplies sensation to much of the face and head.

The trigeminal nerve separates into three divisions - the ophthalmic nerve (supplying sensation to the eye), the maxillary nerve (supplying sensation to the upper jaw), and the mandibular nerve (supplying sensation to the lower jaw). The trigeminal nerve has both motor and sensory functions. This means it carries messages to the brain from the face and it carries "instructions" from the brain to the jaw muscles to tell them when and how to move the jaw.

It is believed that one migraine-triggering factor may be stimulation of the trigeminal nucleus by increased neck and jaw muscle activity, such as clenching or grinding the teeth. Very often this behavior is unknown or unrecognized by the individual and can occur both during the day and when asleep. Intraoral dental devices are available to help an individual who is prone to jaw clenching to control this behavior, thereby reducing the possibility of excessively stimulating or "overloading" the trigeminal nerve system.

Dentists with appropriate training and an interest in treating migraine can examine headache patients and determine if they are candidates for an intraoral device to help reduce or eliminate painful stimulus from jaw muscles. These devices are made in different configurations covering all or some of either the upper or lower teeth. There are different schools of thought regarding the design of the different appliances, but all are intended to reduce the amount of jaw muscle activity be decreasing or altering clenching and grinding of the teeth.

One particular device that has received attention recently by being approved by the FDA is called the NTI-tss (Nociceptive Trigeminal Inhibition - tension suppression system), which was developed and patented by a dentist. The NTI-tss is an oral device that covers the upper four front teeth. Since there is some evidence that this device can be effective for treating migraines when used in the right circumstances, the Food and Drug Administration approved the marketing of the NTI-tss for the prevention of migraine headaches. This FDA approval was based on some research that shows that intraoral appliances can reduce the incidence of migraine headaches. Standards for approving medical devices are generally less stringent than those for approving medications.

Migraine patients who are interested in having this device made for them are cautioned that the scientific research showing the effectiveness of the NTI-tss is not conclusive at this point. Other dental appliances that have been used for over 40 years have also been effective in reducing jaw muscle activity and may be equally successful in reducing the kind of nerve stimulation that can trigger a migraine.

Any dental appliance that is fitted requires periodic balancing and supervision during the entire period the device is worn. There are some potential problems that can result from wearing one of these dental appliances, including increased pain in the jaw joints, jaw muscle soreness, changes in the way the teeth fit together and loosening of some teeth. These problems are almost always manageable and often do not occur if the appliance is correctly made and supervised.

In summary, it is important for the migraine sufferer to realize that many factors can contribute to the development of their headache. Recent research has shown that reduction in the amount of stimulation to the trigeminal nerve system may help in preventing a migraine. A dental device may be one way to decrease activity of the trigeminal nerve system. A physician or dentist with special training in treating headaches and facial pain should always supervise the overall management of the patient’s migraine headache.

"Headache", Winter 2001-2002, Vol. 12, Issue 4