An in new depth understanding of facial morphogenesis is essential so that clinician can grasp.
Differences between normal and range of abnormal.
Biologic reasons for these variations and differences.
Reasons for rationales utilized in diagnosis, treatment planning and selection of appropriate clinical process.
Biologic reasons underlying the problems of retention, rebound and relapse after treatment.
It can be difficult, but clinically very important to decide weather an individual is merely at the extreme of the normal variation of changes in proportions expected for that individual.
Rather than categorizing people as normal or abnormal, it is more useful to think in terms of deviations from the usual pattern and to express variability quantitatively. One way to do this is to evaluate a given child relative to peers on a standard growth chart.