Permanent Molars An Overview

General Descriptions Largest, most posterior teeth Non-succedaneous Eruption pattern: 1st and last permanent teeth to erupt

Arch Positions 6th, 7th, and 8th in each arch First molars: “6-year” molars Second molars: “12-year” molars Third molars: “wisdom teeth”

Function Mainly grinding 1st molars are “cornerstones of occlusion” Maintenance of “vertical dimension of occlusion”

General Characteristics Crowns generally largest and most complex of all teeth At least 3 cusps, typically 4 or 5 At least 2 buccal cusps Normally multirooted

Permanent Maxillary Molars

Introduction Larger M-D and F-L to other maxillary teeth except: shorter O-C O-C dimension is less than M-D and F-L (FL>MD>OC) Largest to smallest: 1st, 2nd, 3rd molars

General Characteristics of Maxillary Molars: Crowns wider F-L than M-D* Usually 4 cusps: ML, MB, DB, DL (largest to smallest) 2 3 1 4

Maxillary molars… Buccal cusps closer to same size; lingual cusps differ in size Presence of oblique ridge and distolingual groove*

Maxillary molars… Crowns are rhomboidal or heart-shape (occlusal view) One buccal pit and one lingual pit Three occlusal pits: mesial, central, distal

Maxillary molars… Crowns are trapezoidal from facial, lingual, proximal views Facial HOC at cervical third Lingual HOC at middle third Usually 3 root branches: L, MB, DB (largest to smallest)

How To Tell Right From Left: Distolingual groove/oblique ridge MB root broader than DB root Buccal ridge prominence towards mesial

Permanent Mandibular Molars

Introduction General size diminishes from 1st to 3rd molars Shorter O-C than premolars and anteriors

General Characteristics of Mandibular Molars Crowns wider M-D than F-L Crowns rectangular (occlusal view) Crowns rhomboidal from proximal view Crowns trapezoidal from facial or lingual views

Mandibular molars… Usually 4 - 5 cusps; both lingual cusps nearly same size MB, ML, DL, DB, D (largest to smallest cusps) - mandibular 1st molar Three occlusal pits: mesial, central, distal Two buccal pits - 1st molar One buccal pit - 2nd molar No lingual pit 4 1 5 3 2

Mandibular molars… Presence of two root branches (M & D), but usually three pulp canals: MB, ML, D Facial HOC at cervical third Lingual HOC at middle third

Incline planes:

How To Tell Right From Left: Mesial root broader than distal root Distal cusp of 1st molar MB “bulge” of crown with 2nd and 3rd molars

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