Well, with my male cat, his don't "over-grow" really, it's just really how extremely hooked and sharp they are. I've had many cats, 3 currently, I've never declawed any cats, and I've never seen any cat except him that had claws grow like his do. He's 14 and always had this issue. This subject just made me kind of ponder if, with his constant painful yanking and such (I've actually seen him dangle from one claw from the back of a chair because he was caught in it
) if he actually wouldn't have done better declawed simply for the fact of the way his claws grow. If he was an outdoor cat and didn't have to worry about getting caught in things like fabrics and such it might not have been an issue, but I've pulled him loose from things his whole life and proceeded to clip his claws. I try to remember to do it on a regular basis, but I swear they grow fast. He's quite use to, and I believe thankful for, the clippings. He lays on his back on my lap, legs stretched out, and just lets me clip with no fight at all. In fact, he purrs while I do it.