Discontinuities in occlusal relationship and the regulation of facial growth. A cybernetic view

Abstract

This study aims to test the reality of the concept of an overall regularity of the biological mechanism that controls growth. Two hundred and thirty individuals were classified by a method (Lavergne and Gasson) which identifies patients who are morphogenetically alike, morphologically alike, grow alike, and who respond in the same way to a given type of treatment. A transformation coefficient was calculated for 25 points of the bony profile to assess whether facial development was regular or irregular. The results are discussed in terms of cybernetic theory and catastrophe theory. At crucial moments of facial development very small fluctuations can result in either of two very different types of occlusal relationship.