In most cases, bruxism in children is a sleep disorder, but it may be linked to other causes. These include:

• Rett syndrome, a neurological and developmental disorder occurring mostly in girls
• Central nervous system-stimulating medicines such as those used to treat attention-deficit/hyperactivity disorder (ADHD)
• Temporomandibular disorders
• Stress

For most people, bruxism occurs when they are asleep and unaware of the grinding. But even if a person is unaware of the habit, a dentist or healthcare provider may suspect bruxism when noting abnormal wear on the teeth. If untreated, bruxism can cause tooth damage and jaw pain.

In adults, tooth grinding may be linked to tension, aggression, or anxiety.

A partner may complain of the grinding noise at night, particularly if it keeps them awake.

Other symptoms include abnormal tooth wear, jaw soreness, facial pain, and headache.

People who have bruxism often also have other sleep disorders, such as sleep apnea or snoring. They often feel tired after a night's sleep or have headaches in the morning.

People with bruxism may also bite the inside of the cheek or chew on pencils.

The mouth guard is useful at night, to keep the teeth from touching. Behavior-modification techniques can teach the person to relax the jaw and practice keeping the teeth apart while the lips are together.