Some people have facial deformities that may cause the sleep apnea. It simply may be that their jaw is smaller than it should be or they could have a smaller opening at the back of the throat. Some people have enlarged tonsils, a large tongue or some other tissues partially blocking the airway. Fixing a deviated septum may help to open the nasal passages. Removing the tonsils and adenoids or polyps may help also.
Children are much more likely to have their tonsils and adenoids removed.
The only available treatment until the early 1980's was a tracheostomy . A tracheostomy is a surgical procedure where a small hole is cut in the neck and a tube with a valve is inserted into the hole. During the day the valve is closed so the person can speak. At night, the valve is opened, thus avoiding the obstructions. The uvula is removed along with excess tissue.