Experiments were conducted primarily on human cadavers to determine the response characteristics and tolerance of several of the prominent facial bones to blunt impact. Most of the data compiled for the experiments on the zygoma showed that bone strain and head acceleration are almost directly proportional to input force and that tolerance to fracture is dependent upon both magnitude and time duration of the force pulse. The magnitude of force in turn is almost directly proportional to the velocity of impact while the pulse duration is virtually independent of velocity.
Preliminary results on the effects of cadaver soft tissue covering the bone indicates that with soft tissue protection the zygoma can absorb blows of 40% to 80% higher energy than without the soft tissue, before fracture occurs. Also, preliminary results on the monkey show only a slight difference in response to blows to the zygomatic arch between the live and a 15 day embalmed animal.