Abstract: Many health care professionals and patients are unclear of the role that dentists may play in the management of Obstructive Sleep Apnoea-Hypopnoea Syndrome (OSAHS.) The dentists’ role is primarily in the construction of appliances for OSAHS but in the United States of America some dentists have practices limited to “Sleep dentistry”. However, in the United Kingdom there is limited training for dentists in this field. This thesis aims to review the relevant literature that pertains to OSAHS and dentistry and then, through three studies, to look at the past, present and future involvement of dentists in OSAHS. Assessing outcome is clearly important and this thesis firstly presents patient-based findings of the long term success of mandibular advancement appliances. Secondly, the experience and views of dentists and sleep specialists, assessed by questionnaire, is presented. Finally, a prospective study of a promising screening tool (the Kushida Index) for the diagnosis of sleep apnoea is carried out.