Orthodontic treatment can have some impact on sleep disorders in patients.
In children, the most common sleep disorder is obstructive sleep apnea (OSA).
Sleep disorders in children are often called sleep disordered breathing (SDB). OSA in children is associated to some degree with a narrow upper jaw and a high narrow palate. There is abundant research that shows improvement in sleep disordered breathing in children with rapid maxillary expansion. Any treatment done by an orthodontist designed to improve a sleep disorder in children should be done in conjunction with a sleep physician.
In adults, OSA is also the most common sleep disorder. Expansion of the upper jaw is much more limited in adults than in children so improvement of sleep disorders is not very successful in this way.
There are many types of removable appliances for adults that are worn during sleep that will hold the lower jaw forward, which has an opening effect on the airway and can improve OSA significantly. Some orthodontists provide this treatment.
Any treatment of sleep disorders in adults should be done in conjunction with a sleep physician.