tooth 1a: A outside of a molar: 1 crown, 2 neck, 3 roots; B cross section of a molar: 1 enamel, 2 dentin, 3 pulp, 4 cementum, 5 gum; C dentition of adult human, upper; D dentition of adult human, lower: 1 incisors, 2 canines, 3 bicuspids, 4 molars
Each tooth consists of three portions: the crown, projecting above the gum; the root, imbedded in the alveolus; and the neck, the constricted portion between the crown and root.
