A Guide To Dental Anatomy

THE PERMANENT MAXILLARY INCISORS

The maxillary central incisor is larger than the lateral incisor. These teeth supplement each other in function, and they are similar anatomically.

PERMANENT MAXILLARY CENTRAL INCISOR

The maxillary central incisors are esthetically the most prominent teeth in the mouth. An ideal smile should have incisal dominance, i.e. maxillary incisors should be the most prominent teeth visible when one smiles. Any defects in the form and alignment of these teeth are easily noticed, and adversely affect the normal facial appearance

First evidence of calcification 3–4 mo
Enamel completed 4–5 yr
Eruption 7–8 yr
Root completed 10 yr

maxillary central inciser

Maxillary Lateral Incisor

Because the maxillary lateral incisor supplements the central incisor in function, the crowns bear a close resemblance. The lateral incisor is smaller in all dimensions except root length. This tooth differs from the central incisor in its development, which may vary considerably. Maxillary lateral incisors vary in form more than any other tooth in the mouth except the third molar. If the variation is too great, it is considered a developmental anomaly. A common situation is to find maxillary lateral incisors with a nondescript, pointed form; such teeth are called peg-shaped laterals.

First evidence of calcification 10–12 mo
Enamel completed 4–5 yr
Eruption 8–9 yr
Root completed 11 yr

The Permanent Mandibular Incisors

The mandibular incisors have smaller mesiodistal dimensions than any of the other teeth. The central incisor is somewhat smaller than the lateral incisor, which is the reverse of the situation in the maxilla.

Mandibular Central Incisor

Generally, the mandibular central incisor is the smallest tooth in the dental arches. The crown has little more than half the mesiodistal diameter of the maxillary central incisor; however, the labiolingual diameter is only about 1 mm less. The single root is very narrow mesiodistally and corresponds to the narrowness of the crown, although the root and crown are wide labiolingually. The length of the root is as great as, if not greater than, that of the maxillary central incisor.

mandibular central inciser

First evidence of calcification 3–4 mo
Enamel completed 4–5 yr
Eruption 6–7 yr
Root completed 9 yr

Mandibular Lateral Incisor

Direct comparison is made with the mandibular central incisor, and the variations are mentioned. The two incisors operate in the dental arch as a team; therefore their functional form is related. As with the mandibular central incisor, the shape of the lateral incisor is uniform compared with that of other teeth. Rarely, it will have a labial and lingual root division in the cervical third. Somewhat more commonly it has two canals in the single root.

First evidence of calcification 3–4 mo
Enamel completed 4–5 yr
Eruption 7–8 yr
Root completed 10 yr