Multiple studies have been conducted on bruxism but no definitive answer can be given as to the cause. In some cases, kids may grind because the top and bottom teeth aren’t aligned properly. Others do it as a response to pain, such as an earache or teething. Many kids outgrow these fairly common causes for grinding.
Stress, usually nervous tension or anger, can be another cause. For instance, a child might worry about a test at school or a change in routine (a new sibling or a new teacher). Even arguing with parents and siblings can cause enough stress to prompt teeth grinding or jaw clenching. Bruxism can be commonly seen in children with medical conditions such as ADHD, Cerebral Palsy, Autism Spectrum and other neurological or muscular conditions. Many medications used to treat these conditions can cause bruxing as well.