As Stephen says, if you are shooting consistently each time you pick up the bow, but not from one time to the next, perhaps your eye is not in the same orientation with respect to the arrow each time. It's not so much that your eye has to be exactly over the arrow each time, but if it's a quarter inch to the left one time, it should always be a quarter inch to the left, and your brain will adjust. Having a double anchor will help you to always have your eye in the same orientation with respect to the arrow. Your "eye tooth index finger" anchor is really a pivot which could allow you to cant the bow without an equal cant in your head, thus moving the arrow from one side to the other under your eye.
Terry Green recommends brushing your thumb along your cheek each time you draw the bow and finding an anchor for your thumb, in addition to the corner-of-mouth (or in your case eyetooth) anchor to maintain the same orientation of the bow to your head each shot. Rick Welch recommends finding a thumb anchor, such as touching your thumb knuckle to your ear lobe, and doing away entirely with the corner-of-mouth anchor and instead touching your nose to the back of the cock feather. You can probably find your own double anchor, but whatever you use should be for the purpose of eliminating the potential for the bow to pivot independently of your head.