Medical Conditions and Bruxism
ADHD – One of the most common childhood disorders that can continue through adolescence and into adulthood.23 A person is unable to control behavior due to difficulty in processing neural stimuli, accompanied by an extremely high level of motor activity.17 In ADHD, bruxism is caused by extensive sleep disturbances and medications used to treat the disorder.24
Autism – A neurodevelopmental disorder described by impaired social interaction, verbal and non-verbal communication and restricted and repetitive behavior. Bruxism can be caused by the antipsychotic medications used in its treatment, high stress and anxiety experienced with autism.25
Brain Injury – There are many conditions that fall into this category. The most common include: strokes, brain damage, dementia or Alzheimer’s disease and traumatic brain injuries, including concussions. Bruxism is a secondary disorder of these conditions.4
Cerebral Palsy – Considered a neurological disorder caused by a non-progressive brain injury or malformation that occurs during development of the brain. This condition primarily affects body movement and muscle coordination. Bruxism is a secondary disorder due to accompanying abnormal conditions in the oral cavity. These patients usually have a higher incident of crowding, variable sizes, shapes and misaligned teeth, all which can promote bruxing. They also experience frequent seizures and are more prone to head and mouth trauma, biting the lips and cheeks and grinding the teeth. Cerebral palsy patients can have trouble swallowing, chewing and can also be more susceptible to gagging and choking.26
Depression – A mental illness that causes sadness. A patient experiences a mood of sadness or a more severe condition of deep depression with possible suicidal thoughts. Patients may only have one episode depending on a particular life situation or with most people it is a reoccurring condition. Episodes may last a few months to many years. The state of mind including unconscious unresolved emotions and medications taken for depression may cause bruxing. Depressed individuals wanting to forget their problems tend to turn to alcohol and/or drugs, which is another source of bruxism.27
Down Syndrome – Also known as Trisomy 21, is a genetic disorder caused by all or part of a third copy of the chromosome 21. This condition is usually associated with physical growth delays, characteristic facial features and mild to moderate intellectual disability. These patients tend to have smaller than average teeth with shorter roots, missing teeth, and a Class III occlusion with crowding. This crowding results in some permanent teeth being unable to erupt. Bruxism is a common side effect of these oral conditions.28
Fibromyalgia – Fibromyalgia is a disorder characterized by widespread musculoskeletal pain accompanied by fatigue, sleep, memory and mood changes. Many people suffering from Fibromyalgia also experience sleep disturbances which increases the possibility of nocturnal bruxing. Seventy-five percent of patients with fibromyalgia have Temporomandibular Joint Disorder (TMD) leading to pain in the face, neck, shoulders and back. This disorder increases in severity with bruxism. Since fibromyalgia can increase stress, sleep disturbances and pain, grinding and clenching may be a side effect of this condition. Wearing a night guard or orthotic occlusal plate usually lessens the discomfort of his condition.29
Obsessive-compulsive Disorder – An anxiety disorder in which people have unwanted and repeated thoughts, feelings, ideas, sensations (obsessions) or behaviors that make them feel driven to do something (compulsion). Bruxism can be caused from the anxiety involved and from the side effects of the serotonin reuptake inhibitors medications used to treat this disorder.30,31
Parkinson’s Disease – A chronic and progressive disorder of the central nervous system, which involves the malfunction and death of vital nerve cells–causing a movement disorder. This condition is often treated with Levodopa, also known as L-DOPA. The brain converts it into dopamine which aids in body movement. Bruxism is a side effect of the long-term use of the medication Levodopa.32
Sleep Disorders – Conditions include snoring, breathing pauses during sleep, sleep apnea, obstructive sleep apnea, sleep talking or mumbling and consistent nocturnal awakenings. Violent injurious behaviors during sleep may include hypnagogic and hypnopompic hallucinations, (visual, auditory or other sensory events that occasionally occur with the transition of falling asleep or waking up.) 33 These sleep disorders, along with the previously discussed mini arousals, prevent a sound consistent sleep and tend to increase the risks of bruxing.
Best sleeping position is on the back, as the head is straight and the least amount of stress, pressure and force is placed on the head and jaw. The worst position is on the stomach, as that puts pressure and force on the jaw and head and adds extra stress to the jaw muscles and TMJ.
Alternately sleeping on the left or right side can determine right or left side bruxing. Sleeping on one side for a long time may induce unilateral bruxism. Sleeping in the horizontal supine position can lead to bilateral bruxism with a high level of posterior neck pain and stiffness.34
Upper Respiratory Airway Syndrome
Bruxism can be a circumstance from Upper Airway Resistance Syndrome (UARS), a greater effort in breathing to get past anatomical obstructions. Upper airway resistance syndrome occurs when the body detects increased pressure in the airways, and when pressure increases volume decreases. Commonly described as breathing through a straw. Upper airway resistance syndrome occurs most commonly due to partial narrowing and increased resistance in the retropalatal (between the hard palate and the uvula) and retroglossal (between the uvula and the epiglottis) locations. This is not sleep apnea, which is when breathing stops or pauses, UARS is less air getting through.
When UARS is present, respiratory effort (related arousals) is common due to higher pressure in the airways and sends a choking message to the brain. When this happens throughout the night the body cannot enter REM sleep.
Obstructive respiration during sleep causes the mandible to fall back while bringing the tongue with it. This triggers a reflexive attempt to open the airway by increasing masseter tone. When this happens, the body goes into survival mode and the brain activates the sympathetic stress system to open the airway pushing the jaw forward to improve respiration. This initiates grinding, causing the bottom teeth to press against the top as the brain attempts to increase the volume in the airway.35
Finding the underlying cause for UARS is recommended to treat the anatomical issues rather than feeding the symptoms. Issues to address are upper airway obstructions such as nasal anatomy, dental malocclusions or lifestyle which then can relieve the bruxism also.
Oral symptoms to suggest upper airway resistance are:
Previous orthodontics especially with extractions
Small mouth and neck
Long soft palate
Loose or fatty throat tissue
Other symptoms to recognize within a health history review:
Low blood pressure, fainting or light-headedness
Allergies and skin rashes
Sinus pain or infection
Chronic stuffy nose
Headaches and migraines
Digestive issues: irritable bowel syndrome, Crohn’s disease, diarrhea, constipation, bloating
Depression, anxiety, or chronic stress
Cold feet and hands