Obstructive sleep apnoea is very common in middle aged patients, although it can affect any age, and it involves a serious breathing problem that is associated with snoring, day-time sleepiness, poor mode and concentration as well as other serious medical problems such as heart attack and stroke. Treatment of Obstructive sleep apnoea is multidisciplinary and can include orthodontist, surgeon, respiratory specialist and other specialists. Treatment approaches start with conservative treatment such as session of smoking, reducing alcohol consumption and losing weight. This is usually combined with continues positive airway pressure (CPAP) appliance during sleeping. Alternatively, a special appliance called Mandibular advancement appliances can be prescribed by the orthodontist. Mandibular advancement appliance is used during the night time and aim to move the bottom jaw forward to reduce the risk of airway obstruction during sleeping.