Local Anatomical Factors Predisposing to Obstructive Sleep Apnea: A Review

Obstructive sleep apnea (OSA) is a condition that is characterized by collapse of the pharyngeal airway resulting in repeated episodes of airflow cessation, oxygen desaturation, and sleep disruption during the course of night. Obstructive sleep apneahypopnea syndrome (OSAHS) is characterized by repetitive episodes of airflow reduction (hypopnea) or cessation (apnea) due to upper airway collapse during sleep. OSA is classified as mild, moderate or severe. Patients with OSA have excessive daytime sleepiness, and may develop systemic hypertension, right heart failure, and cardiac arrhythmias. The interaction between local or general anatomic factors are important in mediating airway size and may have a strong impact on the development of OSA. Various local anatomical factors that can have an impact on the upper airway and predisposing to OSA are the craniofacial bony factors and soft tissue factors. Craniofacial bony anatomical factors include the mandible and the hyoid bone. Soft tissue factors include tongue, uvula, soft palate, tonsils and lateral pharyngeal wall. This article discusses in detail the various local anatomic factors predisposing to OSA. It is very evident from this review that various local anatomic factors play a role in the development of Obstructive Sleep Apnea.