Maxillary Molars

Generals of Molars Generals of Molars and Maxillary Molarsand Maxillary MolarsGenerals of Molars Generals of Molars and Maxillary Molarsand Maxillary Molars

Howard Chi, D.M.D.Howard Chi, D.M.D.Howard Chi, D.M.D.Howard Chi, D.M.D.

Learning ObjectivesLearning ObjectivesLearning ObjectivesLearning Objectives

• Generals of MolarsGenerals of Molars

• Anatomy of Maxillary MolarsAnatomy of Maxillary Molars

• Generals of MolarsGenerals of Molars

• Anatomy of Maxillary MolarsAnatomy of Maxillary Molars

Generals of MolarsGenerals of MolarsGenerals of MolarsGenerals of Molars

General DescriptionGeneral DescriptionOf MolarsOf MolarsGeneral DescriptionGeneral DescriptionOf MolarsOf Molars

• There are 12 permanent molarsThere are 12 permanent molars

• First, second and third on each side, both First, second and third on each side, both on the upper and lower archon the upper and lower arch

• Under universal numbering system they are Under universal numbering system they are 1,2,3,14,15,16,17,18,19,30,31,321,2,3,14,15,16,17,18,19,30,31,32

• There are 12 permanent molarsThere are 12 permanent molars

• First, second and third on each side, both First, second and third on each side, both on the upper and lower archon the upper and lower arch

• Under universal numbering system they are Under universal numbering system they are 1,2,3,14,15,16,17,18,19,30,31,321,2,3,14,15,16,17,18,19,30,31,32

General Description General Description Of MolarsOf MolarsGeneral Description General Description Of MolarsOf Molars

• The first molars are centered in the arch The first molars are centered in the arch anteroposteriorlyanteroposteriorly

• This is one reason their loss is so This is one reason their loss is so devastating to arch continuitydevastating to arch continuity

• They are the largest and strongest teeth in They are the largest and strongest teeth in the archthe arch

• The first molars are centered in the arch The first molars are centered in the arch anteroposteriorlyanteroposteriorly

• This is one reason their loss is so This is one reason their loss is so devastating to arch continuitydevastating to arch continuity

• They are the largest and strongest teeth in They are the largest and strongest teeth in the archthe arch

General Description Of MolarsGeneral Description Of MolarsGeneral Description Of MolarsGeneral Description Of Molars

• Frequently, one or more of the third molars Frequently, one or more of the third molars are congenitally missingare congenitally missing

• This occurs in nearly 20% of the populationThis occurs in nearly 20% of the population

• Frequently, one or more of the third molars Frequently, one or more of the third molars are congenitally missingare congenitally missing

• This occurs in nearly 20% of the populationThis occurs in nearly 20% of the population

Can be congenitallymissing

General Description General Description Of MolarsOf MolarsGeneral Description General Description Of MolarsOf Molars

• The combined mesiodistal width of the three The combined mesiodistal width of the three mandibular molars on one side make up mandibular molars on one side make up 51% of the mesiodistal dimension of their 51% of the mesiodistal dimension of their quadrantquadrant

• The maxillary molars constitute 44% of The maxillary molars constitute 44% of their quadrants mesiodistal dimensiontheir quadrants mesiodistal dimension

• The combined mesiodistal width of the three The combined mesiodistal width of the three mandibular molars on one side make up mandibular molars on one side make up 51% of the mesiodistal dimension of their 51% of the mesiodistal dimension of their quadrantquadrant

• The maxillary molars constitute 44% of The maxillary molars constitute 44% of their quadrants mesiodistal dimensiontheir quadrants mesiodistal dimension

51%

44%

Function Function Of MolarsOf MolarsFunction Function Of MolarsOf Molars

• Play a major role in the mastication of food Play a major role in the mastication of food (chewing and grinding)(chewing and grinding)

• Lost of first molar can result in more than Lost of first molar can result in more than 80mm of chewing surface gone80mm of chewing surface gone

• Play a major role in the mastication of food Play a major role in the mastication of food (chewing and grinding)(chewing and grinding)

• Lost of first molar can result in more than Lost of first molar can result in more than 80mm of chewing surface gone80mm of chewing surface gone

Function Of Function Of MolarsMolarsFunction Of Function Of MolarsMolars

• Important in maintaining vertical dimension of Important in maintaining vertical dimension of the facethe face

• Important in maintaining continuity within dental Important in maintaining continuity within dental arches, thus keeping other teeth in alignment arches, thus keeping other teeth in alignment

• Function in esthetics by keeping the cheeks full Function in esthetics by keeping the cheeks full and keeping chin proper distance from the noseand keeping chin proper distance from the nose

• Important in maintaining vertical dimension of Important in maintaining vertical dimension of the facethe face

• Important in maintaining continuity within dental Important in maintaining continuity within dental arches, thus keeping other teeth in alignment arches, thus keeping other teeth in alignment

• Function in esthetics by keeping the cheeks full Function in esthetics by keeping the cheeks full and keeping chin proper distance from the noseand keeping chin proper distance from the nose

Class Traits Class Traits Of MolarsOf MolarsClass Traits Class Traits Of MolarsOf Molars

• Crown Size And ShapeCrown Size And Shape– Have occlusal surfaces with three to five cusps– Have broader occlusal surfaces than other teeth

• Crown Size And ShapeCrown Size And Shape– Have occlusal surfaces with three to five cusps– Have broader occlusal surfaces than other teeth


• Crown Size And ShapeCrown Size And Shape– Crowns of molars are wider mesiodistally than

long occlusocervically– Are shorter occlusocervically than other teeth

• Crown Size And ShapeCrown Size And Shape– Crowns of molars are wider mesiodistally than

long occlusocervically– Are shorter occlusocervically than other teeth


• Taper From Buccal To LingualTaper From Buccal To Lingual– Molar crowns taper to the lingual (i.e. crown is

narrower on the lingual surface than the buccal surface)

– Exception may be maxillary first molars with large distolingual cusps (may taper toward the buccal)

• Taper From Buccal To LingualTaper From Buccal To Lingual– Molar crowns taper to the lingual (i.e. crown is

narrower on the lingual surface than the buccal surface)

– Exception may be maxillary first molars with large distolingual cusps (may taper toward the buccal)


• Taper To The DistalTaper To The Distal– From an occlusal view all molar crowns taper

distally

• Taper To The DistalTaper To The Distal– From an occlusal view all molar crowns taper

distally

M D


• Contact AreasContact Areas– Mesial: At or near the

junction of the occlusal

and middle thirds– Distal: Middle third

• Contact AreasContact Areas– Mesial: At or near the

junction of the occlusal

and middle thirds– Distal: Middle third

Arch Traits Of MolarsArch Traits Of MolarsArch Traits Of MolarsArch Traits Of MolarsCrown Shape From OcclusalCrown Shape From Occlusal

Maxillary

– square /parallelogram

– B-L>M-D

Mandibular

– rectangular/pentagonal

– M-D>B-L

Crown Shape From OcclusalCrown Shape From Occlusal

Maxillary

– square /parallelogram

– B-L>M-D

Mandibular

– rectangular/pentagonal

– M-D>B-L

Arch Traits Of MolarsArch Traits Of MolarsArch Traits Of MolarsArch Traits Of Molars

Number and Relative Number and Relative Size of CuspsSize of Cusps

Maxillary: 4-5 CuspsMaxillary: 4-5 Cusps– Crown centered over roots– ML cusp: Largest and longest; connects to DB

cusp by the Oblique Ridge– ML>MB> DB>DL

Number and Relative Number and Relative Size of CuspsSize of Cusps

Maxillary: 4-5 CuspsMaxillary: 4-5 Cusps– Crown centered over roots– ML cusp: Largest and longest; connects to DB

cusp by the Oblique Ridge– ML>MB> DB>DL

DL ML

DB MB


MaxillaryMaxillary

Cusp of Carabelli: Cusp of Carabelli:

• If present, is the fifth and If present, is the fifth and

smallest cuspsmallest cusp

• Usually on lingual of ML Usually on lingual of ML

cusp of maxillary cusp of maxillary

first molarsfirst molars

MaxillaryMaxillary

Cusp of Carabelli: Cusp of Carabelli:

• If present, is the fifth and If present, is the fifth and

smallest cuspsmallest cusp

• Usually on lingual of ML Usually on lingual of ML

cusp of maxillary cusp of maxillary

first molarsfirst molars


Number and Relative Size of CupsNumber and Relative Size of Cups

• Mandibular: 4-5 CuspsMandibular: 4-5 Cusps– ML and DL cusps are nearly equal in size (in

contrast to maxillary molars)– Distal Cusp is minor fifth cusp, found on the

first and sometimes third molars

Number and Relative Size of CupsNumber and Relative Size of Cups

• Mandibular: 4-5 CuspsMandibular: 4-5 Cusps– ML and DL cusps are nearly equal in size (in

contrast to maxillary molars)– Distal Cusp is minor fifth cusp, found on the

first and sometimes third molars


• Mandibular TiltMandibular Tilt– All mandibular teeth, including

molars, tilt lingually when

viewed from mesial or distal

(this is not apparent on maxillary molars)– Crowns tilt distally relative to the long axis of

the root

• Mandibular TiltMandibular Tilt– All mandibular teeth, including

molars, tilt lingually when

viewed from mesial or distal

(this is not apparent on maxillary molars)– Crowns tilt distally relative to the long axis of

the root

B L

Arch Traits Arch Traits Of MolarsOf MolarsArch Traits Arch Traits Of MolarsOf Molars

• Maxillary RootsMaxillary Roots– MB, DB, and Palatal

roots – Roots are nearly twice

as long as the crown– Relative length: Palatal>MB>DB

• Maxillary RootsMaxillary Roots– MB, DB, and Palatal

roots – Roots are nearly twice

as long as the crown– Relative length: Palatal>MB>DB

MBDB

Palatal


• Maxillary RootsMaxillary Roots– Roots converge into a

broad cervical root base

called the Root Trunk

• Maxillary RootsMaxillary Roots– Roots converge into a

broad cervical root base

called the Root Trunk

Arch Traits Arch Traits Of MolarsOf MolarsArch Traits Arch Traits Of MolarsOf Molars

• Mandibular RootsMandibular Roots– Two Roots (Mesial and Distal)– Mesial root is usually slightly longer than distal

root– Mandibular root trunks are shorter than

maxillary root trunks, especially on first molars

• Mandibular RootsMandibular Roots– Two Roots (Mesial and Distal)– Mesial root is usually slightly longer than distal

root– Mandibular root trunks are shorter than

maxillary root trunks, especially on first molars

Root Trunk

Anatomy of Anatomy of Maxillary MolarsMaxillary MolarsAnatomy of Anatomy of Maxillary MolarsMaxillary Molars

Type Traits of Type Traits of Maxillary 1st Maxillary 1st and 2nd Molarsand 2nd Molars


• Relative Size Relative Size – Second molar is smaller than the first molar in

the same mouth, especially M-D– 1st Molar is broader than the 2nd Molar– 2nd Molar crown is often tipped distally on the

root trunk

• Relative Size Relative Size – Second molar is smaller than the first molar in

the same mouth, especially M-D– 1st Molar is broader than the 2nd Molar– 2nd Molar crown is often tipped distally on the

root trunk



• Buccal GrooveBuccal Groove– Lies between buccal cusps and extends on the

buccal surface to the middle third of the crown– Pit is sometimes present at the end of the

groove that can be the site of caries

• Buccal GrooveBuccal Groove– Lies between buccal cusps and extends on the

buccal surface to the middle third of the crown– Pit is sometimes present at the end of the

groove that can be the site of caries



• Proximal Contacts Proximal Contacts Same as for all molars: – Mesial: Junction of

occlusal and middle thirds– Distal: Middle third

• Proximal Contacts Proximal Contacts Same as for all molars: – Mesial: Junction of

occlusal and middle thirds– Distal: Middle third

Mesial



• Outline ShapeOutline Shape– The crown appears to tilt

distally at the cervix– This, coupled with a short distobuccal cusp

makes the crown appear shorter on the distal than the mesial

• Outline ShapeOutline Shape– The crown appears to tilt

distally at the cervix– This, coupled with a short distobuccal cusp

makes the crown appear shorter on the distal than the mesial



• RootsRoots– Are attached to a root trunk (longer in second molars)

at the cervical line– Apical to the root trunk there is a split into three roots– Furcation usually located at the junction of the cervical

and middle thirds of the roots

• RootsRoots– Are attached to a root trunk (longer in second molars)

at the cervical line– Apical to the root trunk there is a split into three roots– Furcation usually located at the junction of the cervical

and middle thirds of the roots



• RootsRoots– Three roots splitting of the root trunk is called a

trifurcation

• RootsRoots– Three roots splitting of the root trunk is called a

trifurcation

Maxillary First Maxillary First Molar RootsMolar Roots

Maxillary First Maxillary First Molar RootsMolar Roots

• Much variation in the shapes of rootsMuch variation in the shapes of roots

• The MB and DB roots are often bent in such The MB and DB roots are often bent in such a way as to resemble the handles of a pair a way as to resemble the handles of a pair of pliersof pliers

• This is a contrast to second molars which This is a contrast to second molars which have MB and DB roots closer and more have MB and DB roots closer and more nearly parallelnearly parallel

• Much variation in the shapes of rootsMuch variation in the shapes of roots

• The MB and DB roots are often bent in such The MB and DB roots are often bent in such a way as to resemble the handles of a pair a way as to resemble the handles of a pair of pliersof pliers

• This is a contrast to second molars which This is a contrast to second molars which have MB and DB roots closer and more have MB and DB roots closer and more nearly parallelnearly parallel

1st 2nd

Maxillary First Maxillary First Molar Roots Molar Roots Maxillary First Maxillary First Molar Roots Molar Roots

• The MB and DB roots often curve distallyThe MB and DB roots often curve distally

• The apical third of the MB root The apical third of the MB root maymay curve curve distally enough to put its apex distal to the distally enough to put its apex distal to the buccal groovebuccal groove

• The MB and DB roots often curve distallyThe MB and DB roots often curve distally

• The apical third of the MB root The apical third of the MB root maymay curve curve distally enough to put its apex distal to the distally enough to put its apex distal to the buccal groovebuccal groove

Maxillary Second Maxillary Second Molar RootsMolar RootsMaxillary Second Maxillary Second Molar RootsMolar Roots

• MB and DB roots less curved than on first MB and DB roots less curved than on first molarmolar

• More nearly parallel with each otherMore nearly parallel with each other

• Both bent toward the distal in the apical Both bent toward the distal in the apical third third

• MB and DB roots less curved than on first MB and DB roots less curved than on first molarmolar

• More nearly parallel with each otherMore nearly parallel with each other

• Both bent toward the distal in the apical Both bent toward the distal in the apical third third

2nd

Lingual Aspect Lingual Aspect Of Maxillary MolarsOf Maxillary MolarsLingual Aspect Lingual Aspect Of Maxillary MolarsOf Maxillary Molars

• Crown - Relative Size and TaperCrown - Relative Size and Taper– Due to the prominent DL cusp, crown may be

as wide or wider on the lingual for the first molar

– This is not as likely on the second molar

• Crown - Relative Size and TaperCrown - Relative Size and Taper– Due to the prominent DL cusp, crown may be

as wide or wider on the lingual for the first molar

– This is not as likely on the second molar

Lingual Aspect Lingual Aspect Of Maxillary Of Maxillary

MolarsMolars

Lingual Aspect Lingual Aspect Of Maxillary Of Maxillary

MolarsMolars

• The crown of the second molar usually The crown of the second molar usually appears smaller than the first molarappears smaller than the first molar

• This is due mainly to the smaller or This is due mainly to the smaller or nonexistent DL cuspnonexistent DL cusp

• The crown of the second molar usually The crown of the second molar usually appears smaller than the first molarappears smaller than the first molar

• This is due mainly to the smaller or This is due mainly to the smaller or nonexistent DL cuspnonexistent DL cusp

1st 2nd

Number And Description Of Number And Description Of Lingual Cusps - First MolarLingual Cusps - First MolarNumber And Description Of Number And Description Of Lingual Cusps - First MolarLingual Cusps - First Molar

• Two well defined cusps, ML and DLTwo well defined cusps, ML and DL

• ML is usually the highest and largest of all ML is usually the highest and largest of all cusps on any maxillary molarcusps on any maxillary molar

• Often a fifth cusp, the cusp Often a fifth cusp, the cusp

of Carabelli, which varies of Carabelli, which varies

greatly in size and development greatly in size and development

• Two well defined cusps, ML and DLTwo well defined cusps, ML and DL

• ML is usually the highest and largest of all ML is usually the highest and largest of all cusps on any maxillary molarcusps on any maxillary molar

• Often a fifth cusp, the cusp Often a fifth cusp, the cusp

of Carabelli, which varies of Carabelli, which varies

greatly in size and development greatly in size and development 1st

Number And Number And Description Of Lingual Description Of Lingual Cusps - Second MolarCusps - Second Molar

Number And Number And Description Of Lingual Description Of Lingual Cusps - Second MolarCusps - Second Molar

• There are two types of maxillary second There are two types of maxillary second molars based on number of cusps, 4 or 3molars based on number of cusps, 4 or 3

• On the four-cusp second molar there is a On the four-cusp second molar there is a ML and DL cuspML and DL cusp

• On the three-cusp second molar the DL On the three-cusp second molar the DL cusp is missingcusp is missing

• There are two types of maxillary second There are two types of maxillary second molars based on number of cusps, 4 or 3molars based on number of cusps, 4 or 3

• On the four-cusp second molar there is a On the four-cusp second molar there is a ML and DL cuspML and DL cusp

• On the three-cusp second molar the DL On the three-cusp second molar the DL cusp is missingcusp is missing

Roots Of First Molars Roots Of First Molars From The LingualFrom The LingualRoots Of First Molars Roots Of First Molars From The LingualFrom The Lingual

• On first molars the palatal root is the third On first molars the palatal root is the third longest of any maxillary tooth (after canine longest of any maxillary tooth (after canine and second premolar)and second premolar)

• Tapers apically to a blunt or rounded apexTapers apically to a blunt or rounded apex

• There is usually a depression on the lingual There is usually a depression on the lingual aspect of the palatal root aspect of the palatal root

• On first molars the palatal root is the third On first molars the palatal root is the third longest of any maxillary tooth (after canine longest of any maxillary tooth (after canine and second premolar)and second premolar)

• Tapers apically to a blunt or rounded apexTapers apically to a blunt or rounded apex

• There is usually a depression on the lingual There is usually a depression on the lingual aspect of the palatal root aspect of the palatal root

Depression

Roots Of Second Molars Roots Of Second Molars From The LingualFrom The LingualRoots Of Second Molars Roots Of Second Molars From The LingualFrom The Lingual

• The lingual (palatal) root is as long as the The lingual (palatal) root is as long as the lingual root of the first molarlingual root of the first molar

• The buccal roots bend towards the distal The buccal roots bend towards the distal and are more paralleland are more parallel

• The lingual (palatal) root is as long as the The lingual (palatal) root is as long as the lingual root of the first molarlingual root of the first molar

• The buccal roots bend towards the distal The buccal roots bend towards the distal and are more paralleland are more parallel

Note Distal Bend

Proximal Aspect Proximal Aspect Of First MolarsOf First MolarsProximal Aspect Proximal Aspect Of First MolarsOf First Molars

• CuspsCusps– From the mesial, the crown

appears broad faciolingually – Two or three cusps can be seen from the mesial

(MB, ML, and Cusp of Carabelli)– Distal cusps are shorter and generally not seen

from the mesial

• CuspsCusps– From the mesial, the crown

appears broad faciolingually – Two or three cusps can be seen from the mesial

(MB, ML, and Cusp of Carabelli)– Distal cusps are shorter and generally not seen

from the mesial

1 2 3


• Mesial marginal ridge is more Mesial marginal ridge is more

occlusal than distal, thus very little of theocclusal than distal, thus very little of the

occlusal table can be seen from mesialocclusal table can be seen from mesial

• There is considerable narrowing of the There is considerable narrowing of the occlusal surface from crest of curvature, occlusal surface from crest of curvature, resulting in a narrow occlusal tableresulting in a narrow occlusal table

• Mesial marginal ridge is more Mesial marginal ridge is more

occlusal than distal, thus very little of theocclusal than distal, thus very little of the

occlusal table can be seen from mesialocclusal table can be seen from mesial

• There is considerable narrowing of the There is considerable narrowing of the occlusal surface from crest of curvature, occlusal surface from crest of curvature, resulting in a narrow occlusal tableresulting in a narrow occlusal table


• From the distal, four cusps are visible (may From the distal, four cusps are visible (may also see Cusp of Carabelli)also see Cusp of Carabelli)

• From the distal, four cusps are visible (may From the distal, four cusps are visible (may also see Cusp of Carabelli)also see Cusp of Carabelli)

Distal

Proximal Aspect Proximal Aspect Of Of

Second MolarsSecond Molars

Proximal Aspect Proximal Aspect Of Of

Second MolarsSecond Molars

• From the mesial and distal aspect, looks From the mesial and distal aspect, looks much like the first molar, but no cusp of much like the first molar, but no cusp of Carabelli is presentCarabelli is present

• DL cusp is absent on more than one third of DL cusp is absent on more than one third of these teeththese teeth

• From the mesial and distal aspect, looks From the mesial and distal aspect, looks much like the first molar, but no cusp of much like the first molar, but no cusp of Carabelli is presentCarabelli is present

• DL cusp is absent on more than one third of DL cusp is absent on more than one third of these teeththese teeth

Mesial Distal

Crest Of Crest Of CurvatureCurvatureCrest Of Crest Of CurvatureCurvature

• On the buccal is located in the cervical On the buccal is located in the cervical thirdthird

• On the lingual (palatal) in the middle thirdOn the lingual (palatal) in the middle third

• On the buccal is located in the cervical On the buccal is located in the cervical thirdthird

• On the lingual (palatal) in the middle thirdOn the lingual (palatal) in the middle third

L B

Taper Narrower Taper Narrower To DistalTo Distal

Taper Narrower Taper Narrower To DistalTo Distal

* On both first and second molars, the crown * On both first and second molars, the crown is narrower buccolingually on the distal is narrower buccolingually on the distal than the mesialthan the mesial

* On both first and second molars, the crown * On both first and second molars, the crown is narrower buccolingually on the distal is narrower buccolingually on the distal than the mesialthan the mesial

2ndDistal

1stDistal

Marginal Marginal RidgesRidges

Marginal Marginal RidgesRidges

• On both first and second molars the mesial On both first and second molars the mesial marginal ridge is concave and more marginal ridge is concave and more occlusally located than the distal marginal occlusally located than the distal marginal ridgeridge

• It is also longer buccolingually than the It is also longer buccolingually than the distal marginal ridgedistal marginal ridge

• On both first and second molars the mesial On both first and second molars the mesial marginal ridge is concave and more marginal ridge is concave and more occlusally located than the distal marginal occlusally located than the distal marginal ridgeridge

• It is also longer buccolingually than the It is also longer buccolingually than the distal marginal ridgedistal marginal ridge

2ndMesial

1stMesial

TuberculesTuberculesTuberculesTubercules

• If present are usually If present are usually

found on the mesial found on the mesial

marginal ridge of first marginal ridge of first

molars (rarely found on molars (rarely found on

2nd molars or distal 2nd molars or distal


molars)molars)

• If present are usually If present are usually

found on the mesial found on the mesial


molars (rarely found on molars (rarely found on

2nd molars or distal 2nd molars or distal


molars)molars)

1stMesial

Marginal Marginal Ridge Ridge

GroovesGrooves

Marginal Marginal Ridge Ridge

GroovesGrooves

• Marginal ridge grooves are more common Marginal ridge grooves are more common on the mesial than the distal on the mesial than the distal

• More common on first molars than second More common on first molars than second molarsmolars

• Marginal ridge grooves are more common Marginal ridge grooves are more common on the mesial than the distal on the mesial than the distal

• More common on first molars than second More common on first molars than second molarsmolars

2ndMesial

1stMesial

CervicalCervical Line Line

CervicalCervical Line Line

• The mesial cervical line has a slight The mesial cervical line has a slight occlusal curvatureocclusal curvature

• There is slightly less curvature on the distal There is slightly less curvature on the distal than the mesial than the mesial

• The mesial cervical line has a slight The mesial cervical line has a slight occlusal curvatureocclusal curvature

• There is slightly less curvature on the distal There is slightly less curvature on the distal than the mesial than the mesial

1stDistal

1stMesial

• The mesial contact area is a the junction of The mesial contact area is a the junction of the middle and occlusal thirdsthe middle and occlusal thirds

• The distal contact area is in the middle The distal contact area is in the middle thirdthird

• The mesial contact area is a the junction of The mesial contact area is a the junction of the middle and occlusal thirdsthe middle and occlusal thirds

• The distal contact area is in the middle The distal contact area is in the middle thirdthird

1stDistal

1stMesial

Proximal Proximal ContactsContactsProximal Proximal ContactsContacts

Roots Of Maxillary Roots Of Maxillary Molars From Molars From The ProximalThe Proximal


• From the mesial view the MB root is broad From the mesial view the MB root is broad buccolingually and is shorter than the buccolingually and is shorter than the lingual rootlingual root

• The MB root obscures the view of the DB The MB root obscures the view of the DB rootroot

• Apex of the MB root is in line with the MB Apex of the MB root is in line with the MB cusp tipcusp tip

• From the mesial view the MB root is broad From the mesial view the MB root is broad buccolingually and is shorter than the buccolingually and is shorter than the lingual rootlingual root

• The MB root obscures the view of the DB The MB root obscures the view of the DB rootroot

• Apex of the MB root is in line with the MB Apex of the MB root is in line with the MB cusp tipcusp tip

MB



• The lingual root is the longest and often The lingual root is the longest and often banana shapedbanana shaped

• On first molars extends well beyond the On first molars extends well beyond the crown linguallycrown lingually

• Usually curved buccolinguallyUsually curved buccolingually

• The lingual root is the longest and often The lingual root is the longest and often banana shapedbanana shaped

• On first molars extends well beyond the On first molars extends well beyond the crown linguallycrown lingually

• Usually curved buccolinguallyUsually curved buccolingually

L

Roots Of Maxillary Roots Of Maxillary

Molars From Molars From The ProximalThe Proximal

Roots Of Maxillary Roots Of Maxillary

Molars From Molars From The ProximalThe Proximal

• From the distal, the DB root is shorter and From the distal, the DB root is shorter and narrower than the MB rootnarrower than the MB root

• Can see the outline of both roots from the Can see the outline of both roots from the distaldistal

• From the distal, the DB root is shorter and From the distal, the DB root is shorter and narrower than the MB rootnarrower than the MB root

• Can see the outline of both roots from the Can see the outline of both roots from the distaldistal

Distal



• On second molars roots are much less On second molars roots are much less spread apart spread apart

• Lingual roots is also straighter, usually not Lingual roots is also straighter, usually not extending past confines of the crownextending past confines of the crown

• On second molars roots are much less On second molars roots are much less spread apart spread apart

• Lingual roots is also straighter, usually not Lingual roots is also straighter, usually not extending past confines of the crownextending past confines of the crown

2ndMesial

1stMesial

Occlusal AspectOcclusal AspectOf Of First MolarsFirst Molars

Occlusal AspectOcclusal AspectOf Of First MolarsFirst Molars

• The contour of first molars The contour of first molars

is not square, but gives that is not square, but gives that

impression when compared to other teethimpression when compared to other teeth

• It is roughly a parallelogram It is roughly a parallelogram

• The contour of first molars The contour of first molars

is not square, but gives that is not square, but gives that

impression when compared to other teethimpression when compared to other teeth

• It is roughly a parallelogram It is roughly a parallelogram

Occlusal AspectOcclusal AspectOf Of Second MolarsSecond Molars


• The second molar is wider buccolingually The second molar is wider buccolingually than mesiodistally and tapers to the lingualthan mesiodistally and tapers to the lingual

• Much variation in second molar due to size Much variation in second molar due to size and location of DL cuspand location of DL cusp

• The second molar is wider buccolingually The second molar is wider buccolingually than mesiodistally and tapers to the lingualthan mesiodistally and tapers to the lingual

• Much variation in second molar due to size Much variation in second molar due to size and location of DL cuspand location of DL cusp



• The four-cusp version of the second molar The four-cusp version of the second molar is less square in appearanceis less square in appearance

• The four-cusp version of the second molar The four-cusp version of the second molar is less square in appearanceis less square in appearance

Number And Number And Size Of CuspsSize Of CuspsNumber And Number And Size Of CuspsSize Of Cusps

• Generally there are four cuspsGenerally there are four cusps

• First molar possess a fifth cusp 70% of the First molar possess a fifth cusp 70% of the timetime

• Second molar may be missing the DL cuspSecond molar may be missing the DL cusp

• Generally there are four cuspsGenerally there are four cusps

• First molar possess a fifth cusp 70% of the First molar possess a fifth cusp 70% of the timetime

• Second molar may be missing the DL cuspSecond molar may be missing the DL cusp

14

3 2

514

3 2

Oblique Ridge Unique Oblique Ridge Unique To Maxillary MolarsTo Maxillary MolarsOblique Ridge Unique Oblique Ridge Unique To Maxillary MolarsTo Maxillary Molars

• The oblique ridge connects the DB cusp The oblique ridge connects the DB cusp with the ML cuspwith the ML cusp

• It is present in second molars, but smaller It is present in second molars, but smaller than the oblique ridge of first molarsthan the oblique ridge of first molars

• The oblique ridge connects the DB cusp The oblique ridge connects the DB cusp with the ML cuspwith the ML cusp

• It is present in second molars, but smaller It is present in second molars, but smaller than the oblique ridge of first molarsthan the oblique ridge of first molars

Fossae On Fossae On Four-Cusp Four-Cusp MolarsMolars

Fossae On Fossae On Four-Cusp Four-Cusp MolarsMolars

• There are generally four There are generally four

fossae on four-cusp molarsfossae on four-cusp molars1) Central Fossa

2) Mesial Triangular Fossa

3) Distal Triangular Fossa

4) Distal Fossa

• There are generally four There are generally four

fossae on four-cusp molarsfossae on four-cusp molars1) Central Fossa

2) Mesial Triangular Fossa

3) Distal Triangular Fossa

4) Distal Fossa

1 234

Grooves On Four-Cusp MolarsGrooves On Four-Cusp MolarsGrooves On Four-Cusp MolarsGrooves On Four-Cusp MolarsBuccal Groove

Central GrooveCentral GrooveCentral GrooveCentral Groove

Transverse GrooveOf The ObliqueRidge

Lingual Groove Fifth Cusp Groove

Distal ObliqueGroove

Fossae And Grooves Fossae And Grooves On On

Three-Cusp MolarsThree-Cusp Molars

Fossae And Grooves Fossae And Grooves On On

Three-Cusp MolarsThree-Cusp Molars

• The distal fossae and both the distal oblique The distal fossae and both the distal oblique and lingual grooves are absentand lingual grooves are absent

• The distal fossae and both the distal oblique The distal fossae and both the distal oblique and lingual grooves are absentand lingual grooves are absent

Maxillary Third Maxillary Third MolarsMolarsMaxillary Third Maxillary Third MolarsMolars

Maxillary Third Maxillary Third MolarsMolarsMaxillary Third Maxillary Third MolarsMolars

• General description difficult General description difficult

due to great variationdue to great variation

• Roots and crown shorter than first or Roots and crown shorter than first or second molarsecond molar

• Crown often possess more supplemental Crown often possess more supplemental groovesgrooves

• May possess three, four or five cuspsMay possess three, four or five cusps

• General description difficult General description difficult

due to great variationdue to great variation

• Roots and crown shorter than first or Roots and crown shorter than first or second molarsecond molar

• Crown often possess more supplemental Crown often possess more supplemental groovesgrooves

• May possess three, four or five cuspsMay possess three, four or five cusps

Roots Of Roots Of Maxillary Maxillary

Third MolarsThird Molars

Roots Of Roots Of Maxillary Maxillary

Third MolarsThird Molars

• Possess three roots, but more often they are Possess three roots, but more often they are fused for most of their lengthfused for most of their length

• Roots are shorter than those of first and Roots are shorter than those of first and second molarsecond molar

• Possess three roots, but more often they are Possess three roots, but more often they are fused for most of their lengthfused for most of their length

• Roots are shorter than those of first and Roots are shorter than those of first and second molarsecond molar

Mesial Buccal

Health & Medicine

Maxillary Molars