What is buccal pit?

Normal Tooth Anatomy: A "buccal pit" is a variation of normal tooth anatomy on lower back teeth. If you look closely at a lower molar, on the cheek side, you'll see two lobes which come together with a small groove between them. Sometimes during tooth development this groove doesn't fuse all the way, leaving a small pit behind. This pit nearly always decays early in life and should be filled, ideally prior to a cavity.