Obstructive sleep apnea is a common sleep disorder which is associated with significant morbidity and mortality. OSA is characterised by frequent episodes of hypoxia due to upper airway collapse during sleep. In the presence of an anatomically compromised, collapsible airway, the sleep-induced loss of compensatory tonic input to the upper airway dilator muscle motor neurons leads to collapse of the pharyngeal airway. It has adverse effects on sleep quality and leads to daytime fatigue and sleepiness. It is essential for dental professionals to be aware of the signs and symptoms of OSA, for timely identification diagnosis as well starting treatment with oral appliances, if indicated. While many patients experience a complete or partial resolution of their symptoms, some do not improve or may even become worse. It is therefore imperative that physicians conduct progress evaluations, while the respective dental care provider continues to make adjustments, optimising the effectiveness of the chosen appliance.