Can Growth Hormone Advance Bone Age

Can Growth Hormone Speed up Bone Age?  My son was born 4lbs 16inches long.  He was diagnosed with IUGR, SGA, not growth hormone defecient.   By the time he was 2.5 he was showing no signs of catching up and still under 1% on the growth chart.  He has been on GHT for 2 years and is currently 4.5 years old.  His two bottom teeth have come out suddenly and he permanent teeth are coming in already.  We went to our peds endocrinologist yesterday and did a bone age x-ray.  His bone age came out as a 7 year old.  He did jump from 0%-11% on GHT, but now as a 7 year old bone age, it would put him back to 1%.  We are working with doctors, but it seems a mystery to all.  They said that GHT does not advance bone age without seeing a huge jump in height which we have not seen.  I am conflicted as the doctors are if to keep him on GHT or stop it.......