Molars

Molars are the most posterior teeth in the human dentition, specialized for grinding and crushing food. In adult humans there are 12 molars, three in each quadrant: first molars, second molars, and third molars (wisdom teeth). They erupt after the incisors and canines, with the first molars typically appearing around age 6, the second around age 12, and the third from the late teens to early twenties; third molars are frequently impacted or extracted.

Anatomy: Molars have broad crowns with multiple cusps and large chewing surfaces. Maxillary (upper) molars usually have three roots, while mandibular (lower) molars typically have two roots. The first molars often have five cusps on the occlusal surface, and some individuals display the cusp of Carabelli on the mesiolingual cusp. The internal structure includes enamel, dentin, and a relatively large pulp chamber with a complex root canal system.

Function and occlusion: Molars grind and crush food during mastication and help maintain vertical dimension of the face. They occlude with premolars and other molars, contributing to efficient chewing and stable jaw guidance during movement.

Development and variation: Molars develop from the dental lamina, with crown formation preceding eruption and root formation continuing afterward. Variants include agenesis or impaction of the third molars, as well as differences in cusp patterns. Molars are common sites for dental caries and periodontal disease due to pits, fissures and proximity to the gums.