Central or central incisors refers to the first four teeth at the centre of the mouth. The typical mouth has four central teeth, upper left central, upper right central, lower left central and lower right central. Humans have a total of eight incisor teeth. The mouth or oral cavity is composed of the incisors, canines, premolars and molars, the hard and soft palate, gums, uvula, tonsil, and tongue surrounded by the lips.