Obstructive sleep apnea is considered to be an ever rising problem faced by not only adults but also growing kids. Class II malocclusion associated with retrognathic mandible is found to be strongly co-ordinated with this problem. Invasive treatment has its drawbacks, this book reviews the problem as such with its signs and symptoms, epidomolgical aspect, severe consequences if untreated and an orthodontist role in treating the issue with a non-invasive approach.