Non-restorative sleep has considerable consequences for daily life. A sleep disorder is recognized by symptoms such as daytime fatigue and performance or concentration disorders. Furthermore, it increases the risk of developing cardiovascular, metabolic, and neurologic diseases. The diagnosis and therapy of sleep disorders is not only in the sleep medicine doctor's hands. A multidisciplinary approach reflects the affected patients' choice. Dentists can make an important contribution, especially to the therapy of sleep-related breathing disorder.