Undiagnosed obstructive sleep apnea (OSA) can contribute to hypertension, cardiovascular disease, stroke, and detract from overall quality of life. Dentists can play an important role in detecting, making recommendations for, and treating OSA with oral appliances (OAs). A survey of 18 questions of knowledge and opinion of, educational background for, and clinical experience with OSA and OAs was mailed to 500 general practice dentists in Indiana, United States. Two hundred survey returns produced 192 valid responses. Responders reported strong positive opinions toward OSA and OAs. However, 58% of dentists could not identify common signs and symptoms of OSA, and 55% of dentists did not know the mechanism for mandibular advance devices. Only 39% of dentists could identify snoring, mild OSA, and intolerance to continuous positive airway pressure as possible indications for OA treatment. Respondents reported a general lack of education about both OSA and OAs. Only 31 (16%) were taught about this issue in dental school; 77 (40%) knew little or nothing about OA treatment for OSA patients; 57 (30%) learned from postgraduate training. Cooperation and referrals between dentists and physicians were rated as "poor." Of the responders, 54% never consulted with physicians for a suspected OSA patient in their practice; 75% of dentists reported they have never been referred patients by physicians; and 80% of dentists never or less than five times prescribed OAs to OSA patients. Results suggest a need for increased education and training regarding OSA and OAs in dental school, as well as increased cooperation between dentists and physicians for better patient care.