Like the other two mamas mentioned, every baby is different! My daughter started sprouting at three months and now has two bottom teeth!

Well every child is different but my son got his first teeth on the bottom at 6months and all four front on top coming out at the moment. They first erupted at 8months

Depends on the baby. I know babies still with only bottom teeth at 1 year. My son got 8 teeth and he's 1 year 1 month