The above pictures are two separate 3-D volumetric C-T scans.  The set on the left is taken first without the oral appliance.  The set on the right was taken with the oral appliance in place.  These pictures illustrate why oral appliances are really oral airway dilators.  The main tongue muscle is attached to the inside surface of the lower jaw, just under the incisor teeth roots.  It is obvious that by protruding the the mandible forward, the tongue gets pulled forward and supported so the airway is more open.  What is not obvious is that the lateral dimension of the airway also increases significantly.  The change in jaw position effected by the oral appliance also stretches the muscles surrounding the airway making these devices oral airway dilators.

Enlargements of the individual pictures are shown below so the actual measurements are visible











ALLEN J. MOSES DDS
Assistant Professor
Rush University Medical  School
Chicago, IL
SEARS TOWER
(312) 993-0430