Permanent Molars Review

Vocabulary flashcards covering the characteristics, eruption, anatomy, and numbering of permanent maxillary and mandibular molars.

Permanent Molars

Twelve teeth in the dentition, largest and boxiest, erupt after all deciduous teeth and are usually the first permanent tooth to erupt.

Occlusal cusps of molars

Typically dominated by MB, ML, DB, DL cusps, with a potential fifth supplemental cusp.

First Molars (Eruption)

Erupts at 6-7 years, with root completion at 9-10 years, and 5 lobes of development.

Second Molars (Eruption)

Erupts at 11-13 years, with root completion at 14-16 years, and 4 lobes of development.

Third Molars (Eruption)

Erupts at 17-22 years, with root completion at 18-25 years, and 4 lobes of development.

Maxillary Molars (General)

Typically have five cusps, five lobes of development, three roots (MB, DB, LI), and three root furcation openings.

Primary Cusp Triangle

Formed by the three major cusps on the occlusal surface of maxillary molars: MB, ML, DB.

Cusp of Carabelli (Maxillary Molars)

A supplemental cusp usually found on the lingual side of the ML cusp, almost always visible on the maxillary first molar.

Maxillary First Molar

Characterized by five lobes of development (including Cusp of Carabelli), a square or rhomboid occlusal outline, four cusps on occlusal and one supplemental on ML, three roots, and four pulp horns.

Universal Numbering System (Maxillary First Molar)

3, #14.

FDI Numbering System (Maxillary First Molar)

16, #26.

Proximal HOC/Contact area (Maxillary First Molar)

Located in the middle third.

HOC FA (Maxillary First Molar)

Located in the cervical 1/3.

HOC LI (Maxillary First Molar)

Located in the middle 1/3.

ML Cusp (Maxillary First Molar)

The tallest cusp on the maxillary first molar, carrying the Cusp of Carabelli on its lingual surface.

DL Cusp (Maxillary First Molar)

The smallest cusp on the maxillary first molar.

Oblique Ridge (Maxillary First Molar)

A ridge running from the ML to the DB cusp, isolating the DL cusp, and crossed by a transverse groove.

Central Fossa (Maxillary First Molar)

A depression usually containing a pit, located on the occlusal surface.

Distal Fossa (Maxillary First Molar)

A depression usually containing a pit, located on the occlusal surface.

Central Groove (Maxillary First Molar)

A developmental groove that runs from the MMR to the DMR across the occlusal surface.

Buccal Groove (Maxillary First Molar)

A developmental groove that runs from the central groove, crosses over onto the buccal surface, and is visible from both occlusal and buccal aspects.

Distolingual/Lingual Groove (Maxillary First Molar)

A developmental groove that runs from the central groove on the distal side, defines the DL cusp, and crosses onto the lingual toward the distal.

Root Trunk

The area from the Cementoenamel Junction (CEJ) to the opening of the furcation of the root.

Maxillary Second Molar

Typically has four lobes of development, is usually absent of Cusp of Carabelli, has a less square or rhomboid occlusal outline than the first molar, and its roots are closer together.

DL Cusp (Maxillary Second Molar)

Much smaller on the maxillary second molar compared to the first molar.

Universal Numbering System (Maxillary Second Molar)

2, #15.

FDI Numbering System (Maxillary Second Molar)

17, #27.

Maxillary Third Molar

Typically has four lobes of development, Cusp of Carabelli is usually absent, has a heart-shaped occlusal outline, and its roots are usually fused or very close together.

DL Cusp (Maxillary Third Molar)

Usually missing on the maxillary third molar.

Universal Numbering System (Maxillary Third Molar)

1, #16.

FDI Numbering System (Maxillary Third Molar)

18, #28.

Mandibular Molars (General)

Largest mandibular teeth, three in each quadrant, function for chewing/grinding, crowns are wider mesio-distally than bucco-lingually.

Mandibular Molar Size Progression

The first mandibular molar is the largest, and molars get smaller as they move posteriorly.

Mandibular Molar Roots

Have two roots, one mesial and one distal.

Mandibular Molar Furcations

Found on the direct buccal and direct lingual aspects.

Mandibular Molar Cusps

Typically have four major cusps, with the first molar having a fifth minor cusp; two buccal cusps and two lingual cusps are similar in size.

Mandibular First Molar

Erupts at 6-7 years, is the largest tooth in the mandible, and the only mandibular molar with five cusps and five developmental lobes (two buccal, two lingual, one minor distal).

Roots and Pulp Horns (Mandibular First Molar)

Has 2 roots, 5 pulp horns, and usually three root canals (mesial root has 2 canals).

Universal Numbering System (Mandibular First Molar)

19, #30.

FDI Numbering System (Mandibular First Molar)

36, #46.

HOC M/D (Mandibular First Molar)

Located in the middle third (contact area).

HOC BU/LI (Mandibular First Molar)

Located in the cervical third/middle third.

Mandibular Second Molar

Erupts at 11-13 years, is smaller than the first molar, has two roots that are shorter and closer together, and possesses four cusps (two buccal, two lingual) and four developmental lobes.

Cusps (Mandibular Second Molar)

Typically has four cusps (two buccal, two lingual) that are almost equal in size.

Occlusal configuration (Mandibular Second Molar)

Characterized by a cross (+) configuration of grooves on the occlusal surface.

Universal Numbering System (Mandibular Second Molar)

18, #31.

FDI Numbering System (Mandibular Second Molar)

37, #47.

Mandibular Third Molar

The most variable mandibular tooth, often heart-shaped or resembling a first or second molar, with four or five cusps/lobes, and roots usually fused together.

Roots (Mandibular Third Molar)

Typically fused together.

Universal Numbering System (Mandibular Third Molar)

17, #32.

FDI Numbering System (Mandibular Third Molar)

38, #48.

Occlusal Anatomy (Mandibular Third Molar)

Contains many supplemental grooves, has an indistinct pattern, a smaller central fossa, and smaller roots.