Treatment of sleep apnea with mandibular advancement devices (MADs) may be associated with the development of symptoms of temporomandibular disorder (TMD). This article discusses the different types of TMD and orofacial pain problems that may occur during treatment of obstructive sleep apnea (OSA) with a MAD. It is critical that the general dentist who is providing dental devices for OSA perform a thorough physical and neurologic assessment of the temporomandibular joint and associated structures before providing such a device so that preexisting problems are identified and discussed with the patient.