What is Tooth-Grinding (Bruxism)?
Tooth-grinding or “bruxism” is excessive, unconscious grinding of the teeth or clenching of the jaw. This can happen when you’re awake (“awake bruxism”), or when you’re sleeping (“sleep bruxism”.) Bruxism is fairly common, especially in children: it affects 15-40% of kids and 8-10% of adults.
Bruxism in general can be considered a “parafunctional habit”, or a habit of using a body part in ways outside of its main functions. Other mouth-based parafunctional habits include fingernail biting, clothing or pen chewing, and tongue tension/thrusting. Sleep bruxism in particular is considered a sleep-related movement disorder. People who experience sleep bruxism are more likely to experience other sleep-related movement disorders, and vice versa.
Sleep bruxism is often related to conditions that cause micro-arousals from sleep. These micro-arousals then activate the autonomic nervous system (ANS), which is the control center that maintains unconscious bodily functions and responses (such as heart rate, breathing, urination, sexual arousal, and digestion.) In the seconds before a “bruxism event”, there is a consistent pattern of increased ANS activity. This can include elevated heart and respiratory rate, rapid-frequence EEG activity, and increased tone in the jaw and oropharyngeal muscles (such as the muscles of the soft palate, the tonsils, the back of the tongue, and the back and side walls of the throat.) This is immediately followed by an increase in “rhythmic masticatory muscle activity” (RMMA), which activates the same muscles we use to chew food and causes tooth grinding. The grinding usually occurs in clusters of one-second muscle contractions during individual micro-arousals from sleep, and lasts between 3-15 seconds each.
Clenching your jaw or grinding your teeth every once in a while is normal, and usually won’t cause damage. However, if it becomes more frequent, it should be addressed and monitored, both in order to maintain your oral health and in order to maintain your sleep health.
Why Does Sleep Bruxism Happen?
The actual causes of sleep bruxism are not yet fully understood. However, there are several contributing factors that may lead to someone grinding their teeth at night. They include:
- Sleep Disorders, especially Obstructive Sleep Apnea: People who experience sleep disorders such as insomnia, restless leg syndrome, and/or obstructive sleep apnea (or OSA), are at a higher risk for developing sleep bruxism. Having OSA, a sleep disorder in which the body periodically stops breathing during sleep, is considered a particularly high risk factor for developing bruxism.
- Psychiatric, Neurologic, and Physical Disorders: Bruxism can be a symptom of anxiety disorders, depressive disorders, mood disorders, and schizoaffective disorders. It is also experienced at a higher rate among people with epilepsy, Alzheimer’s disease, autism spectrum disorders, Rett syndrome, Huntington disease, cerebral palsy, Parkinson’s disease, Down Syndrome, certain intellectual disabilities, and traumatic brain injury.
- Stress: Situational stress, which can be caused by work, school, relationships, family, money, and many other major stressors in life, can lead to bruxism. This is true of both long-term, sustained stress, and acute, relatively new stress.
- TMJ/TMD: Temporomandibular Joint Disorders (TMJ, TMD) are conditions that affect the chewing muscles and joints that connect your lower jaw (mandible) to your skull. TMJ/TMD can cause pain and improper functioning of the muscles, cartilage, ligaments, blood vessels, and nerves in your jaw, face, and neck, as well as your teeth. TMJ/TMD and bruxism are two different conditions that are sometimes but not always related. While bruxism can be caused by TMJ/TMD, and bruxism can in turn worsen or agitate TMJ/TMD, not all people with TMJ/TMD grind their teeth, and vice versa. Therefore, TMJ/TMD may be a risk factor to consider in some people with bruxism, but that is not necessarily the case for all people with both TMJ/TMD and bruxism.
- Digestion and Reflux Issues: Digestion issues, and specifically Gastroesophageal Reflux Disease (GERD), are risk factors for bruxism. GERD is a condition where highly acidic stomach contents leak into the esophagus. GERD affects around 40% of Americans, and is frequently associated with heartburn, indigestion, and trouble swallowing. In some cases, people with GERD may have their stomach acid reach their mouth/oral cavity. In these cases, the acid can damage the surface of the teeth, especially the molars, and can cause a burning sensation in the mouth, as well as dry mouth. This lack of lubrication, combined with the acid-wear already done to the teeth and the muscles and soft tissues in the mouth, can lead to sleep bruxism.
- Medications: There are a number of medications that are associated with bruxism. Most commonly, it can be linked to ADD/ADHD medications (including amphetamines, methylphenidate, and dexmethylphenidate), depression and anxiety medications (including most SSRIs, SNRIs, NDRIs, and tricyclic antidepressants), dopamine agents such as L-Dopa, which is used to treat Parkinson’s disease, and metoclopramide (Reglan), which is used to help with acid reflux, digestion, and migraines. Some of the most commonly prescribed psychiatric medications, such as Prozac, Zoloft, Paxil, Adderall, and Ritalin, all list bruxism among their potential side effects. In addition, certain strains of medicinal marijuana and CBD products may cause dry-mouth, which can increase the risk of bruxism.
- Food and Beverage Consumption: In addition to foods that cause or trigger acid reflux, there are several common foods, drinks, and substances that are linked to bruxism. Foods and beverages that contain caffeine—such as coffee, tea, energy drinks, and chocolate—can increase the risk of bruxism, as can alcohol and cigarettes. The use of recreational drugs such as cocaine, MDMA/ecstasy, methamphetamine, opioids, and heroin can also cause tooth grinding, both while waking and sleeping.
- Genetics: Some studies suggest that genetic predisposition may play a role in developing bruxism, and that your risk factor for bruxism increases if you have a parent with the same condition. Cross-sectional surveys found that 20-50% of people with bruxism report having at least one parent who also had bruxism.
What are the Signs of Sleep Bruxism?
People with sleep bruxism often have the condition without knowing it, and only notice because people who regularly co-sleep with them point it out. However, there are signs and symptoms of bruxism that you can catch, either with a co-sleeper or on your own. The main indicators of sleep bruxism include:
- Awake bruxism and other parafunctional oral activities (ie, cheek biting, pen chewing, tongue thrusting).
- Headaches, especially around the temple.
- Jaw pain
- Clicking of the temporomandibular joints (the joints in the jaw)
- Triggered or worsening TMD/TMJ
- Trismus (restricted mouth opening, otherwise known as “lockjaw”)
- Issues with the muscles of mastication (four muscles in the mouth, face, and jaw that facilitate chewing), including growth of those muscles, as well as tenderness, pain, fatigue, and/or hypersensitivity.
- Burning, pain, and/or indentations in the tongue.
- Earache, felt either in the ear itself or in front of the ear (also known as preauricular pain).
- Dental symptoms, such as tooth pain and hypersensitivity, excessive wear and enamel erosion, easily fractured or chipped teeth, increased failure of dental fixtures (such as crowns and fillings), loosened teeth, and even tooth loss.
What Damage Can Sleep Bruxism Do?
Bruxism can cause significant damage to your teeth, your masticatory system (including the muscles of mastication), your periodontium (the tissue surrounding and supporting the teeth), and the bones and joints in your jaw. This damage can get more severe the longer it goes on unchecked, and can lead to more severe health complications, including tooth and tissue loss, muscular damage, permanent jaw damage, hypermobility, and, in some severe cases, alteration of the shape of your face, which can be disfiguring. Bruxism can also damage the soft tissues of the mouth, including the tongue, lips, and cheeks.
How Do I Stop or Prevent Sleep Bruxism?
If you think you may have sleep bruxism, there are many ways to address it. It is advisable to seek the help of a medical professional, like a doctor or dentist, but some of these methods can be tried on your own, or with remote medical supervision. They include:
- Addressing underlying conditions. Because bruxism can be caused by underlying health conditions, it is important to discover if there is one specific health issue that is the root cause of the bruxism. In some cases, bruxism is a symptom that is best addressed by treating the underlying condition. This is especially relevant for issues like obstructive sleep apnea and other sleep disorders, which can lead directly to bruxism. In cases where bruxism can be clearly linked to stress, working on stress reduction techniques may be the best way to stop grinding your teeth while you sleep.
- Addressing potential medication interactions: Bruxism can also be a side effect of medications for other conditions. If you take medication, do some research and find out if bruxism is a possible side effect. If it is, you can work with your doctor to see if they can adjust or switch out your prescription for one that is less likely to cause bruxism.
- Changing your diet and/or eating habits: Since bruxism is associated with foods that cause poor sleep and poor digestion, you may want to consider eliminating or reducing those foods, including but not limited to coffee, energy drinks, tea, chocolate, alcohol, and things with very high sugar content. You may also consider eliminating sleep-damaging recreational drugs and cigarettes/nicotine products. If you suffer from indigestion and especially GERD, consider cutting out foods that are triggers for you, and making sure you give yourself plenty of time to digest between eating and sleep.
- Mouth guard or protective dental device: There are a number of dental devices that are used in order to address the damage caused by chronic bruxism, and even to attempt to treat the condition. There is still limited research on the effectiveness of these devices, but in some cases they do appear to help with the severity and frequency of the symptoms. There are two main types of dental devices for bruxism: occlusal splints (bite splints) and mandibular advancement devices (MADs). Occlusal splints, commonly known as mouth guards, protect the teeth from damage done by chronic bruxism. They usually consist of two custom molded plates that you put over your teeth as you sleep to protect them. MADs are devices similar to mouth guards; they open the airway by moving the jaw (mandible) forward during sleep. Occlusal splints are more commonly used to treat bruxism than MADs; MADs are usually not used unless there is also a case of OSA, which MADs also help treat. Consult your doctor or dentist about your options when it comes to dental devices.
- Improve sleep hygiene: “Sleep hygiene” refers to specific actions and routines that you adopt into your everyday life in order to improve your sleep. In addition to avoiding eating or drinking anything that would interfere with sleep, examples of changes you can make to improve your sleep hygiene include:
- Keep a regular sleep schedule. Create and follow a regular sleep schedule so that you go to bed and wake up at approximately the same time every day. Make sure to also set your routine bedtime and wake-up time far enough apart that you will be able to get the recommended amount of sleep (which, for most people, is 7-9 hours).
- Pre-sleep routine. Have a routine before bed, during which you do the same actions in the same order (e.g. putting on pajamas, brushing teeth, some light yoga and/or meditation). This will help your body and mind relax into sleep mode.
- Get up and out ASAP. Try not to spend excess time in bed, and make sure to get out of bed as soon as you wake up. Avoid idling in bed while eating, watching TV, or reading, as this will strengthen the association of bed with activity.
- Quarantine the screens. Limit screen time in the hour before bed, allowing your mind to wind down and detach from the distractions posed by your phone and computer. It might help to use that time for your nightly routine, or to pick up a non-screen nighttime activity, like reading or knitting, or listening to audiobooks or podcasts.
- Move around. Many of us live sedentary lives, and it can be difficult to establish a regular exercise routine. However, it is important to get at least 20 minutes of moderate exercise every day, ideally at least four hours before you go to sleep. This will help your body relax by the time bedtime comes around.
- Improve your sleep space. Create an inner sanctum in your bedroom, or at least make some changes to reduce sleep disturbances. Invest in a comfortable bed suited to your body, and keep the room at a comfortable temperature. Reduce any ambient or intrusive light or sound coming into your room during sleeping hours.
- Expand your toolbox. Consider other therapies or methods to add to your “toolbox”, the set of things you can do to combat sleep issues. If you are constantly struggling with sleep, you can incorporate a number of therapies into your sleep hygiene improvement regimen. Therapies like CBT (cognitive behavioral therapy), biofeedback, and acupuncture, as well as practices like yoga and meditation, can help some people with stubborn sleep issues make headway.
- Medications: In particularly severe cases of sleep bruxism, medications such as amitriptyline, bromocriptine, clonazepam, propranolol, and clonidine have been prescribed to treat bruxism. However, these medications are not always effective, and many have side effects which may be worse than the bruxism itself. Please consult your physician to see if medication is the right choice for you.
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