In CAH when a child is under suppressed, this cause dhea's and androgen's to be made by the adrenals.  This causes too rapid a growth spurt, and all the knock on effects of that.  In a child with normal adrenal glands, dhea's are produced in abundance in the first year (this is what causes teething and the rapid growth at that time), then these levels drop to low amounts and stay that way until the child reaches 6 - 12 years old when they again start to rise and do so until the age of 20 yrs old when they peak. From there on out they start to decrease up to old age.  There ideally should be a fine balance between cortisol and dhea's when treating children with CAH so as to make sure that their growth spurts are as near normal as possible.  We know that when over suppressed this halts the growth and when under suppressed, there is too rapid a growth spurt.  The way they can check that these things are as they should be is by doing the  bone age scans.

This is how I understand this to be anyway.