Midfacial fractures: importance of angle of impact to horizontal craniofacial buttresses.

The complex nature of midfacial fractures is a result of the interaction of impact forces and inherent resistance of the facial bones to displacement. Analysis of fractures created in cadavers shows that impact forces angled obliquely to the horizontal craniofacial buttresses cause LeFort III fractures with inferior and posterior displacement of the midface. Forces directed head-on to the buttresses cause LeFort II-I fractures with inferior rotation of the midface around the lower ends of the pterygoid plates. It appears that the point of impact is of lesser importance in creating midfacial fractures than is the angle of impact in relation to the horizontal craniofacial buttresses. This may explain why victims of equal impact forces at the same level on the face suffer widely varying injuries.