Abstract
The purpose of this study was to evaluate jaw, head and body position-related changes in upper airway dimensions and maximum forced inspiratory airflow. Fifteen male normal subjects were selected and underwent magnetic resonance imaging in the following five different jaw, head and body positions: (1) supine with no jaw protrusion; (2) supine with jaw protrusion; (3) lateral decubitus with jaw protrusion; (4) supine, head rotation with jaw protrusion; (5) pronation, head rotation with jaw protrusion. The dimensional changes of the upper airway were measured according to the magnetic resonance images. To assess the changes in ventilation, the maximum forced inspiratory airflow was tested using a spirometer. This was accomplished with the subjects placed in the positions previously described. Data of airway dimensions and inspiratory velocity were reported using descriptive statistics. The results showed that upper airway dimensions and maximum forced inspiratory airflow changed by the changes of jaw, head and body positions. Jaw protrusion and head rotation could enlarge the upper airway dimensions and provided more maximum forced inspiratory airflow. These positions may prove beneficial for alleviating the symptoms of patients with obstructive sleep apnea syndrome.
