Question
My tree has new growth at the bottom. But at the top of the tree does not looks dead. do i need to prune the top or what?

Answer
Young Japanese maples tend top have winter burn and the upper branches are killed back. Yes prune them back to the main trunk or green growth. This dying branches is part of the growing process of young maples. The root system is growing and trying to keep up with the foliage growth. It should be fine and re grow new foliage and branches.