If the side shoots are making the corn too thick looking, I would break them off. I rarely find many side shoots, but I did with my first planting and broke them off. If your corn is rather thickly spaced, it could be helpful to take the suckers off. They rarely produce ears with normal corn varieties.

The studies I remember say it doesn't matter whether you remove the suckers or not. They don't produce ears but they don't reduce the yield from the main stalk. It won't hurt to remove them if you are somewhat careful about it. If you rip them off you might damage or disturb the main stalk and make it more likely to lodge, ie fall over in a storm.