When the teeth are biting down, the maxillary central incisors occlude with the mandibular central and lateral incisors. The contact point of the mandibular teeth is in the lingual fossa of the maxillary central incisor about 4 mm gingivally from the incisal edge.[23] In this position, the maxillary incisors cover nearly half of the mandibular incisors' crowns. When the maxillary and mandibular incisors do not contact even when the mouth is fully closed, an anterior open bite occurs.