English · Svenska · Deutsch · Español · Latina

Mandibular left third molar

The mandibular wisdom tooth, highly variable in form and position.

Open in 3D →

FDI

38

Universal

17

Palmer

LL8

Roots

Two, often fused

Root canals

Variable

Eruption

About 17–21 years, if at all

Form and anatomy

The crown varies more than any other mandibular tooth. It may resemble a first molar with five cusps or a second molar with four, and the occlusal surface is often crowded with supplemental grooves. The roots are usually shorter than those of the other molars, frequently fused and curved toward the distal. The position in the jaw matters as much as the form: when there is too little space behind the second molar, the tooth may stay impacted, most often tilted mesially, but also vertically, horizontally or distally. Its roots can lie very close to or even around the inferior alveolar canal, and the lingual nerve may run just beneath the thin lingual plate beside it. That is why careful radiographic assessment comes before surgical removal.

Function

Grinding when erupted in function.

Clinical relevance

Frequently impacted. Its roots may lie close to the inferior alveolar canal, and the lingual nerve runs close to the lingual plate here. In Dental Scope this tooth is a derived approximation (see provenance).

Neighbouring teeth

Mesial neighbour

Mandibular left second molar

Same tooth, other side

Mandibular right third molar

Opposing tooth

Maxillary left third molar

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