I can't get my older teenagers to wear their seat belts when driving the car. They insist the air bags will protect them. Am I barking up the wrong tree here? Are they right?

Before air bags were invented, seat belt use was clearly shown to reduce injuries during motor vehicle accidents. That's why so many states enacted a mandatory seat belt law. Your state may have this law in place, which would put an end to the argument immediately.

But if you don't have a mandatory seat belt law, here are some things we know from recent safety studies. Studies show that the use of combined seatbelt and air bags on passengers in the front seat of automobiles has reduced the number of deaths and bodily injuries. The use of an air bag without a seat belt results in more cervical (neck) spine and thoracic (upper back) fractures.

The use of an air bag with the seatbelt produces more spinal fractures. But the severity of the fractures is less. Patients with spine fractures are more likely to be wearing only a seatbelt. Those who wear a seatbelt and have air bags that deploy have fewer spine fractures. The number of spine fractures reported among patients who used only an air bag is equal to those who used no safety measures (no seat belt and no air bag).

Statistical analysis of available data shows that seat belt use alone increases the risk of spine fracture. The combined use of a seat belt and an air bag reduces the risk of cervical and thoracic spinal fractures but does not affect the number of lumbrosacral fractures. Using just an air bag (without a seat belt) increases the risk of a severe thoracic fracture.

Based on the results of current studies, drivers and passengers are encouraged to wear their seat belts even when the vehicle has air bags installed. The risk of a spine fracture (and especially a severe one at that) is less with both safety measures in place. The use of seat belt alone or air bag alone is not advised.