What do you mean by "filing?"

Having an overbite with crowding does not weaken teeth but crowded teeth are more likely to trap food which can result in decay. Generally, the best way to correct both an overbite and crowding is by orthodontic treatment. If the teeth are simply "filed" to correct the overbite, this will remove enamel which may expose the dentine, making the teeth sensitive and more prone to decay. It will also alter the height:width ratio of the teeth (ie. the teeth may look short and wide), resulting in a poor aesthetic result. The teeth, however, may be prepared for veneers to try to correct the crowding.