January 21, 2003

BIRMINGHAM, AL - Air bags are least protective of the very weakest bones of the face and may need to be redesigned to slow down the high-velocity safety devices or re-direct their thrust to more stable parts of the body, say University of Alabama at Birmingham (UAB) researchers in a study of patterns of facial fractures at UAB Hospital.

The study was published in the January/February issue of Archives of Facial Plastic Surgery.

Dr. Art Cox, one of the authors, said, "We found that air bags and seat belts do prevent injury in serious wrecks and that they are most effective when used together. But the high velocity and the trajectory of the air bag itself may cause blunt injury to the cheek and nose area."

Cox, a facial plastic and reconstructive surgeon, is an assistant professor of surgery in the division of otolaryngology. Co-authors were Drs. Payman Simoni and Robert Ostendorf.

The researchers identified 3,731 patients who were treated for severe trauma injuries at UAB from 1996-2000, and noted which kind, if either, of the safety devices were used in each case. The 497 facial fractures they sustained were grouped by location of the factures: nasal, lower jaw, bones of the cheeks and upper jaw (called ZMC fractures), and bones around the eye.

They found that air bags were the least effective in preventing fractures of the cheeks and upper jaw.

Use of seat belts and air bags, especially together, offers a statistically significant reduction in facial fractures in severe motor vehicle crashes, said Cox. "Air bags inflate at a very high velocity, up to 210 mph, although air bag designers have decreased the velocity during the past few years. If a crash is severe enough to cause a facial fracture, air bags are least protective of the ZMC. If further studies can confirm this pattern of injuries, the design of the bags might be altered to provide more protection for the weaker areas of the face."