An incisor is one of the flat, sharp-edged front teeth — four in each jaw — built for cutting and slicing food. Their thin, chisel-like crowns shear through apple skin, crusty bread, and cooked meat with an efficiency no molar can match: the first tools of eating, taking the initial bite that the molars then grind. Human incisors reflect our omnivorous heritage — modest compared with the rodent’s ever-growing chisels or the carnivore’s daggers, but perfectly suited to a diet of cooked, softened foods. Dentists watch them for the earliest signs of wear, erosion from acidic drinks, and orthodontic crowding — the front line of the mouth’s architecture.