Multimodal approach from various medical fields is required to accurately diagnose and appropriately treat obstructive sleep apnea syndrome, and to fully understand its pathogenesis. Dental medicine has contributed to clarifying importance of craniofacial abnormalities for development of obstructive sleep apnea. It also plays a major role in treatment of obstructive sleep apnea with oral appliances, maxillomandible surgeries and orthodontic interventions. It is expected that orthodontic intervention during childhood even in asymptomatic child possibly prevents development of obstructive sleep apnea during adulthood while extensive involvement of the dentists is needed to test the hypothesis.