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Mandibular right central incisor

The smallest tooth of the permanent dentition: a narrow, symmetrical incisor with a single root that is flattened mesiodistally.

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FDI

41

Universal

25

Palmer

LR1

Roots

One, flattened mesiodistally

Root canals

Usually one, sometimes two

Eruption

About 6–7 years

Form and anatomy

The crown is narrow mesiodistally and almost perfectly symmetrical, with sharp, nearly right-angled incisal corners and a straight incisal edge that lies slightly lingual to the long axis of the root. The labial surface is flat to slightly convex; the lingual surface is smooth, with a shallow lingual fossa and faint marginal ridges above a small cingulum. Right and left central incisors are very hard to tell apart. The root is long and ribbon-like: narrow mesiodistally but wide labiolingually, often with shallow depressions on its mesial and distal surfaces. These depressions show why a single root may still carry two canals, one labial and one lingual, which usually rejoin near the apex. The thin alveolar bone over the labial surface is easily lost in periodontal disease.

Function

Cutting food against the maxillary incisors.

Clinical relevance

Although usually single-rooted, a second (lingual) canal is present in a notable minority.

Canal counts in a study

Teeth examined: 192. Adults from a radiology practice in Toulouse, France; left and right teeth combined. CBCT, 200 µm voxels Canal count observed on CBCT; small canals may go undetected.

These are sample frequencies, not universal probabilities. Population, sampling and method affect the results. Root count and canal configuration are different measurements. The 3D model shows one configuration; it does not change with these percentages.

Monsarrat et al. (2016), Table 2

Neighbouring teeth

Mesial neighbour

Mandibular left central incisor

Distal neighbour

Mandibular right lateral incisor

Same tooth, other side

Mandibular left central incisor

Opposing tooth

Maxillary right central incisor

This text is a draft and has not yet been reviewed by a dental professional. Educational reference only, not for diagnosis or treatment.