Findings of a randomized-controlled trial suggest intense nocturnal jaw clenching may serve as a contributing factor to headache-related disability among patients with chronic migraine. Results were published in BMC Neurology, and also confirm a nociceptive trigeminal inhibition (NTI) oral device is one method of assessing whether jaw-clenching contributes to ongoing migraine.

Chronic migraineurs can be refractive to multiple preventive medications while others may be reluctant to use pharmacotherapeutic treatments due to their systemic side effects, researchers explained.

Although the exact underlying pathology of migraine is unknown, the condition is thought to involve overactivity in the trigeminal-occipital-cervical complex of the nerves.

Previous research has implicated habitual nocturnal jaw clenching as a potential migraine trigger, especially among those who have headaches upon waking up or shortly afterwards.

To help address his condition, the NTI was developed to minimize clenching intensity and subsequent afferent nociceptive activity. “The NTI is a semi-custom intraoral mouthpiece approved by the FDA in 2001 for the prophylactic treatment of medically diagnosed migraine pain through reduction of trigeminally-innervated muscular activity,” authors wrote.

In an effort to assess efficacy of the NTI splint in improving disability, researchers conducted a single blind study among 25 chronic migraineurs who presented to a headache center.

All participants were referred to a dental practice to be considered for the study and were treated with both a placebo device and an NTI device, however, “the participants were not aware of which device was FDA approved, while practitioners were familiar with the NTI.”

At baseline, patients completed a Headache Impact Test (HIT-6) questionnaire. After being randomized to either 30 days of NTI splint use or placebo splint use, patients completed another HIT-6 questionnaire and switched to the alternate device. They then completed a final questionnaire after the second 30-day use period.

Of the 25 participants, 19 completed the full trial and patients’ initial average HIT-6 score was 4 or “severe impact, disabling pain.”

Analyses revealed:

68% (17 of 25) of patients using the NTI as measured by sequential HIT 6 scores had at least a 1-category improvement (severe to substantial, or substantial to some, or some to none) compared with 12% (3 of 25) when using a placebo device
36% (9 of 25 ) of patients using the NTI device reported a 2-category improvement in their HIT-6 score, compared with 0% when using placebo
No adverse events were reported by any patients
A Fisher test revealed (P = .00125) that there is a statistically significant difference between NTI and Placebo improvement

“Decreasing peripheral sensitization with modalities such as the NTI splint protocol which reduces chronic nociceptive input can help to decrease central sensitization, which is a hallmark of chronic migraine,” authors wrote.

Although it was approved over 2 decades ago, the NTI has not become a commonly used adjunctive preventive treatment for migraine, potentially due to patients’ negative experiences with traditional dental splints or a lack of knowledge among providers.

“The production of nociceptive input by the affected teeth, bone, [temporomandibular joints] and muscles to the trigeminal sensory nucleus produced by nocturnal jaw clenching should be considered as a potential perpetuating and confounding co-factor of Chronic Migraine,” researchers concluded.

Reference:

Blumenfeld AM, and Boyd JP. Adjunctive treatment of chronic migraine using an oral dental device: overview and results of a randomized placebo-controlled crossover study. BMC Neurology. Published online March 4, 2022. doi:10.1186/s12883-022-02591-8