I have a male that is 18 months old. He has had a scissor bite up until now, it has become slightly an underbite. I know boys keep growing and their heads change, could this correct itself? Never had this problem :-(

My line changes during the first couple years. Heads, bites, tails and whatever. The bites are, IMO, particularly subject to change.

I actually think bites keep changing throughout their life. Bred owned and showed a boy with a level bite, ( didn't start that way) I didn't really start showing him until he was around 16 months old. The level bite never stopped him and he had his CH very quickly. Now at 3 his bite is changing again back to a correct bite.