Answer: It is never recommended to remove the tops of trees, or top them as it is called. This is not a valid pruning form. It destoys the naturally strong structure of the tree. Distorted, weak growth tries to replace the original wood and this new growth is subject to breakage. The tree suffers shock as well. It is not good for trees.
If the trees have dead or damaged branches, these can be carefully and selectively removed to prevent them eventually rotting and falling during a storm. A professionally trained, certified arborist should be consulted and hired for this kind of work. Make sure they have formal scientific training in tree care. They can also evaluate the trees and set your mind at ease with regard to their safety and health or any special concerns.
I'm sorry to sound so strong about this, but it is a truly unfortunate misconception that topping could be a good thing to do. Mature trees in good health should never be topped. The procedure is conterproductive.
Good luck with the trees!
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