The maxillary central incisor is a human tooth in the front upper jaw, or maxilla, and is usually the most visible of all teeth in the mouth.

In the universal system of notation, the deciduous maxillary central incisors are designated by a letter written in uppercase.

[4][page needed] In the Palmer notation, a letter is used in conjunction with a symbol designating in which quadrant the tooth is found.

[4][page needed] The aggregate of cells which eventually form a tooth are derived from the ectoderm of the first branchial arch and the ectomesenchyme of the neural crest.

[7] As in all cases of tooth development, the first hard tissue to begin forming is dentin, with enamel appearing immediately afterwards.

[8][page needed] The deciduous maxillary central incisor begins to undergo mineralization 14 weeks in utero, and at birth 5/6ths of the enamel is formed.

[8][page needed] The permanent maxillary central incisor begins to undergo mineralization when a child is 3–4 months of age.

The diameter of the crown mesiodistally is greater than the length cervicoincisally, which makes the tooth appear wider rather than taller from a labial viewpoint.

The cingulum reaches incisally a great length and is large enough to create small fossa on either side of it.

On the mesial and distal surfaces, the cervical line curves incisally, which is also seen in the permanent maxillary central incisor.

When this tooth is newly erupted into the mouth, the incisal edges have three rounded features called mammelons.

Age differences in the gingival-incisal length of maxillary central incisors are seen and are attributed to normal attrition occurring throughout life.

After the mammelons are worn away, the incisal edge of the maxillary central incisor is straight mesiodistally.

The mesial side of the maxillary central incisor shows the crown of the tooth as a triangle with the point at the incisal edge and the base at the cervix.

The crest of curvature for the palatal and labial surfaces is located directly incisally to the cervical line.

[citation needed] More than any other tooth in the mouth, the cervical line from this view curves tremendously toward the incisal.

[16] During root canal therapy, access into the pulp is frequently located centrally on the lingual surface between the incisal edge and the cingulum.

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.

When the maxillary and mandibular incisors do not contact even when the mouth is fully closed, an anterior open bite occurs.

[citation needed] Sinodonty, a genetic variation occurring in Native Americans and some East Asian populations, is possibly a trait retained from an indigenous East Asian archaic human ancestor Homo Erectus Pekinensis.

Among its features are shovel-shaped incisors that derive their name from the deeper-than-normal lingual fossa and prominent marginal ridges of the teeth.

[citation needed] When space exists between the contacts of the maxillary central incisors, the condition is referred to as a diastema or "gap tooth."

One frequent cause of the space is the presence of a large labial frenum from the upper lip extending near the teeth.

Talon cusps range from less than 1% to 6% of the population, and 33% of cases occur on the permanent maxillary central incisor.

[20] All incisors have the potential to be affected by a case of congenital syphilis, which can cause a notch to form on the incisal edges of these teeth.

"[21] They serve as part of Hutchinson's triad, which also includes interstitial keratitis and eighth nerve deafness.