Facial growth rotation--reflections on definition and cause.

The phenomenon of growth rotation of the jaws during facial development is examined by means of profile roentgencephalometric analysis of a male subject followed from age 4 years to adulthood, with reference to metallic implants and stable natural bony structures. The rotation of the corpora of the jaws, termed total rotation, and its components, matrix and intramatrix rotation, are defined. A description is given of the compensatory remodelling process. The concept of facial growth rotation as essentially a primary phenomenon is supported by a report of an identical facial rotation pattern in growing Macaca mulatta, suggesting that facial growth rotation is common in primates.