Nighttime teeth grinding and clenching:  Teeth grinding and clenching which is referred to as sleep bruxism (SB) has been (mistakenly) in the past, attributed to psychic stress and anxiety but much more is now known about this condition.  SB is now classified by the American Academy of Sleep Medicine as a sleep parasomnia.    Parasomnias are a category of sleep disorders that involve abnormal movements, behaviors, emotions, perceptions, and dreams that occur while falling asleep, sleeping, between sleep stages, or during arousal from sleep. Parasomnias which are better known to most of us include but not limited to:  Sleepwalking (somnambulism), Sleep terrors (night terrors), Teeth grinding (bruxism), Sleep related eating disorder (SRED), Restless legs syndrome & periodic limb movements

SB often occurs during periods of sleep when breathing is impaired, in iron-deficient patients, patients undergoing  renal dialysis, and/or an adverse effect of a prescribed or recreational drug abuse.

Prevalence:  nighttime clenching of the jaws or sleep bruxism (SB) is fairly common and occurs in 60% of healthy persons who may or may not have symptoms upon awakening

Painful vs. non-painful SB:  painful SB most often occurs when there is tooth contact while clenching

Causes:  it is generally accepted that SB is probably part of any arousal response from changes in the depth and quality of sleep.  Conditions often causing a decline in sleep stability which may lead to SB are several but not limited to:   1) snoring, 2) Sleep-Related Breathing Disorders (SRBD) such as Obstructive Sleep Apnea (OSA), increased work of breathing without a decline in oxygen saturation (Upper airway resistance syndrome), 3)  difficulty with nasal breathing, 4) other painful conditions leading to sleep fragmentation such as GERD and rheumatologic problems such as arthritis (rheumatoid, Gout, psoriatic etc.), 4) SSRI-induced SB; use of SSRI, in some individuals, may lead to a dopaminergic deficit and sleep fragmentation leading to SB will result.  Among the SSRIs implicated in the development of SB are:  Citalopram (Celexa), Escitalopram (Lexapro, Cipralex), Paroxetine (Paxil, Seroxat), Fluoxetine (Prozac), Fluvoxamine (Luvox), and Sertraline (Zoloft, Lustral), and 5) other drugs may also lead to SB but less frequently than SSRI but nonetheless, may be significant if/when SB occurs; among these general categories of drugs implicated are:  a) antipsychotics (typically, this does not develop until at least 3-6 months of exposure although, in some instances, it can occur after only a few doses), b) anti-emetics (for nausea c)  illegal or “recreational” , d) Legal prescription medications generally referred to as stimulants often prescribed for ADHD and narcolepsy. 

Breathing-related SB:  when sleeping, especially on the back, with the help of gravity, the mandible falls backward and the airway collapses.  Advancement of the mandible while sleeping can help to maintain airway stability which can reduce clenching/gnashing of the teeth.  This can ben intraoral acrylic mandibular repositioning device prevents or actively promotes advancement of the mandible during sleep.

Drug-induced SB:  In some instances, this may require a reduction, change, or discontinuation of the drug in question.  This should not be attempted without the involvement of the prescribing physician or equally trained health-care professional.  If discontinuation, is not an option, there are drugs which may be prescribed that can mitigate or effectively neutralize this adverse effect very effectively.