Author: Mayoor, Patel, DDS, MS

In yet another study we are introduced to a relationship between sleep and pain. While we have talked about this connection before, I think it is worth noting this study and what has been said. Researchers stated that it is unknown whether and how sleep deprivation influences craniofacial muscle sensitivity in health patients.

They investigated whether total sleep deprivation (TSD) and one night of recovery sleep (RS) was enough to alter mechanical pain sensitivity in temporal and masseter muscles. Fifteen healthy people participated in three consecutive sessions. From this, pressure pain thresholds were measured on the temporal and masseter muscles. And both muscles became sensitized after 24 hours of TSD. With RS, it was able to reverse the muscle sensitization.

This shows us just how important sleep is. If your patients suffer from sleep apnea, treatment is key for preventing increased pain in their jaw muscles or elsewhere in the head. We need to work to improve our patients’ care and well-being through proper diagnosis and treatment planning. Here are some connections with craniofacial pain.

Primary Headaches

These include migraines, tension-type headaches, trigeminal autonomic cephalalgias and hypnic headaches. Sleep quantity is reduced in primary headaches. When a person has an average sleep duration of seven to eight hours, it is associated with reduced headaches. However, when sleep duration is around only six hours it is associated with increased headache intensity.

Sleep can both trigger and cure headaches. For example, sleep can be a trigger factor in cluster headaches. A headache can be the first symptom of sleep deprivation and a sleep disorder, which means it is important to pay attention to how our patients are feeling and the symptoms they are experiencing.

Secondary Headaches

For this category, we see that secondary headaches include sleep apnea-related headaches. Sleep-related headaches are a throbbing pain, which can include nausea and vomiting. As a dentist, you can help provide relief through the availability of an oral appliance. Many times, bite guards or oral appliances can help relieve aching jaw muscles caused by bruxism or misaligned jaws that might be leading to sleep apnea.

Through treatment of sleep apnea with oral appliance therapy, your patients can experience improved sleep while also resolving any pain they might be experiencing from headaches. In addition to oral appliance therapy, it is also important for patients to maintain a regular sleep schedule as well.

Temporomandibular Joint Disorders (TMD)

About 75% of people with TMD have signs that suggest a sleep breathing disorder, such as obstructive sleep apnea (OSA). A narrow upper arch of teeth is 90% predictive of OSA and a retruded chin in 70% predictive of OSA. In other words, teeth grinding and TMD can affect more than just the jaw–it can be an underlying cause for sleep apnea and other sleep disorders.

When TMD is present, it is possible for the jaw to move and for it to become misaligned, which affects the bite and general size of the mouth. This change in size can result in the inability of the mouth to properly accommodate the tongue. When less space is available, the tendency is for the tongue to fall to the back of the mouth, which, in turn, creates a blockage in the air pathway. This obstruction then leads to episodes of pauses in breathing or shallow breathing from sleep apnea.

Painful Cranial Neuropathies

These include trigeminal neuralgia, post-herpetic trigeminal neuropathy, painful post-traumatic trigeminal neuropathy and burning mouth syndrome. Neuropathic pain is associated with sleep disturbances, which leads to poor sleep quality and increased pain sensitivity. This means it is vital that we assess sleep alongside neuropathic pain.

Responses to medication remain inconsistent, causing identification of the best treatment to be challenging. This is why it is important to identify the underlying cause of pain and sleep disturbances in our patients. For example, oral appliance therapy might be the best option to reduce sleep disturbances when sleep apnea is the case.

Pain and Sleep

In patients that suffer from chronic pain, the study states that a self-perpetuating cycle can be set in motion in which joint, myofacial or musculoskeletal disease leads to fatigue. This then leads to decreased exercise and physical deconditioning. Patients then begin to spend more time in bed, which causes their basic circadian cycle to be disrupted.

And as a result, the basic physiologic rhythm of sleep is lost, and this lack of movement and sleep begins to lead to more pain and even more sleep loss. Obtaining less than six hours or more than nine hours of sleep can be associated with greater next-day pain. To help improve sleep among these patients it is important to encourage exercise. More strenuous exercise during the day will help to promote better sleep. Just make sure the exercise patients are performing is completed at least three hours before bedtime.

The link between pain and sleep is clear, but we need to know how to address this in our patients. Evidence suggests that sleep apnea and pain are related, showing that sleep disturbance may impair key processes that contribute to the development and maintenance of chronic pain, including temporomandibular joint (TMJ) pain. Many other studies also suggest that sleep deprivation is correlated with elevated pain severity in chronic pain patients and that in the general population, individual difference in sleep impact subsequent pain.

Continuing Education

We need to ensure we are able to provide proper care for our patients suffering from sleep apnea or craniofacial pain, as well as those suffering from a combination of conditions. As dentists we need to be on the lookout for signs and symptoms of sleep apnea. This is also the case for chronic pain among our patients—especially when the two are connected. Management of patients with chronic craniofacial pain and sleep disorders should address the factors that modulate the pain experience. It should also include both non-pharmacological and pharmacological modalities.

Start today by signing up for an upcoming educational seminar or lecture to learn more about this link between sleep and pain. We host CE courses on clinical treatment of TMD disorders and Dental Sleep Medicine. For more information, contact Nierman Practice Management at 1-800-879-6468 or by visiting our schedule page.