The neck of the tooth is the transition between the crown and the root of the tooth.
The enamel ends around the neck of the tooth with its thinnest part. The neck of the tooth does not form a straight line around the tooth and has different heights: at the point of contact with the adjacent tooth, the neck extends highest towards the crown. In a healthy dentition, the gums cover the necks. Certain diseases or incorrect brushing techniques can cause the gums to flatten and expose the necks of the teeth.