Orthognathic surgery can alter the dental, skeletal, soft tissue, and dimensional changes in the oropharyngeal region. Studies have shown a posterior positioning of the hyoid bone and tongue position after mandibular setback surgery, this in turn can have a negative influence on the upper airway space that could lead to breathing problems such as obstructive sleep apnea. Mandibular setback surgery is commonly used for functional and aesthetic correction in mandibular prognathism patients. There are still some controversial opinions regarding the effect of mandibular setback surgery on the pharyngeal airway space and oxygen saturation. This study aims to review and illustrate the changes in pharyngeal airway space and oxygen saturation following mandibular setback surgery.