Generally the bone age is used to see if there are any growth problems caused by the med's.  It sounds like there is with your child.  My son's bone age was always behind from the age of two years to today's date.  We are due a bone age this month so I don't know for sure if he has made any gains---if he has they have not been positive ones.  What I am finding fascinating is the amount of children I hear about that have bone ages and they are considerably immature of the chronological age.  What action has your doctor propsed.  The problem now is, if your child has been on the dose he/she is currently on for a while, it may be unwise to drop back as you may invite problems in the opposite direction.  Obviuosly there has been SOME growth or surely it would have cropped up on the clinical assessments would it not?  Can they not analyze if the growth has been steady since the last dose raise OR slow to grow and changing to a faster growth.  Surely just looking at the clinical assessments crunching a few numbers would tell the tale?  If growth has speeded up a little, then the child may be catching up with that dose they are on.  If it has slowed right down then there is obvioulsy a problem that needs to be addressed where dose it concerned.