Patients afflicted with obstructive hypersomnia sleep apnea (HSA) have been treated traditionally with permanent tracheostomy. More recently, an association between HSA and mandibular retrognathism has been noted. Several centers have reported rapid reversal of HSA symptoms in retrognathic patients after mandibular advancement. Their experiences are outlined; the anatomy and pathophysiology leading to obstructive HSA are reviewed, and the recommendations for evaluation and patient management are discussed.