Trimming your trees are important to the health of them and outlook. Maintaining proper pruning of a tree takes experience, and knowledge so the tree is not damaged or end up dying in the future. Wrongful cuts or limb removal can affect the trees growth and health.
When a tree is damaged or untrimmed, it can invite unwanted pests to attack the tree even further which will lead to the trees death or decay eventually and could even spread to nearby trees, wreaking havoc on your entire yard.
Air flow is also needed to keep the tree vigorous and healthy from unwanted diseases. So, trim your tree down, and allowing in the sun and air.