Dental sleep medicine traditionally focuses on sleep-related breathing disorders, such as snoring and obstructive sleep apnea. However, everyday practice shows that also other sleep disorders touch on dentistry, including sleep-related orofacial pain, xerostomia, hypersalivation, gastroesophageal reflux disease and bruxism. A new definition, which covers all the diagnostic and treatment aspects of these disorders, has therefore been formulated for dental sleep medicine. This article describes why this development started and sketches the current state of affairs regarding the discipline of dental sleep medicine. The different dental sleep disorders are also described briefly, with special focus on the more remarkable associations between them.