CAT scans are used to analyze airway constriction in relation to head position.
Anything that has the effect of limiting the airway will cause the head position to change to give the patient the most advantageous airway flow.
CAT scans of this type allow for a volumetric analysis of the airway and document changes in air volume related to head position which occur with TMJ degeneration or changes in chin position.
Lateral view CAT scans can also be used as a “zero” magnification Cephalometric Radiograph. The advantage is that it can be used to standardize previous lateral Cephalometric Radiographs which may have been taken with various magnifications. The disadvantage is that they require more radiation dosage. The amount of radiation exposure from a skull CAT scan is 150mrem. The advantage is that once done all of the desired views can be taken from a single exposure.
In this case the airway volume was 10,00045.2mm2 and the minimum axial area was 49.2mm2.
This is a frontal view from a CAT scan showing the airway and the point of constriction. The total volume can be calculated, along with the minimum axial volume. Relative changes in head and jaw position affect the airway. By being able to determine the airway volume we have a way to correlate the head and jaw position with airway volume over time.