Anatomy of Peremanent Molars

8/16/2019 Anatomy of Peremanent Molars

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DescriptiveDescriptive

Anatomy ofAnatomy of

PermanentPermanent

MolarsMolars

Prof. A. Elsahn


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They are twelve in number, three in They are twelve in number, three ineach quadrant named rst, second,each quadrant named rst, second,

and third molar according to theirand third molar according to their

position from the midline.position from the midline.

1)1)Number:Number:

Prof. A. ElsahnProf. A. Elsahn

GeneralGeneral

CharacteristicsCharacteristics


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2) Location:2) Location:

The mandibular molars The mandibular molars

make up over half !"#$ ofmake up over half !"#$ of

the mesiodistal dimension.the mesiodistal dimension.Prof. A. Elsahn

They are the most They are the mostposteriorly situated teethposteriorly situated teethin the mouth, distal to thein the mouth, distal to thesecond premolar.second premolar.

The three ma%illary molars The three ma%illary molarson each side constituteon each side constitute&$ of the mesiodistal&$ of the mesiodistaldimension of thatdimension of that

quadrant.quadrant.

& & #

& & #

! " # ! " #


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))

!unction:!unction:

They are adapted for crushing and They are adapted for crushing and

grinding of the food.grinding of the food.

They help to maintain the proper They help to maintain the proper

vertical dimension and the continuityvertical dimension and the continuity

within the dental arch.within the dental arch.

Prof. A. Elsahn


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")") #cclusal#cclusal

$urface:$urface:

They have wide They have wide

occlusal surface.occlusal surface.

Prof. A. Elsahn


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%) Cusps:%) Cusps:

'olars are multicusped teeth, their'olars are multicusped teeth, their

occlusal surfaces carry three to veocclusal surfaces carry three to vecusps and a comple% pattern of groovescusps and a comple% pattern of grooves

and ridges characteristic for eachand ridges characteristic for each

molar.molar.

The cusps of upper molars are more The cusps of upper molars are more

pronounced than those of lower molars.pronounced than those of lower molars.

Prof. A. Elsahn

""

"""""" ((

((((

((

))))

))

))

&&

&&&&

!!


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&) Cro'ns:&) Cro'ns:

They have large crowns but shorter They have large crowns but shorter

than the premolars.than the premolars.

Prof. A. Elsahn


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() oots:() oots: 'olars are multirooted.'olars are multirooted.

Prof. A. Elsahn

The roots tend to The roots tend tobecome shorter, closerbecome shorter, closertogether and show atogether and show a

greater backwardgreater backward

'andibular molars have'andibular molars havetwo roots, one mesialtwo roots, one mesialand one distal.and one distal.

'a%illary molars have'a%illary molars havethree roots, two buccalthree roots, two buccaland one palatal.and one palatal.

** **

****

''''

''''+. Aspect+. Aspect.Aspect.Aspect


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*) #cclusal*) #cclusal

#utline:#utline: The ma%illary molars are rhomboidal or The ma%illary molars are rhomboidal or

sometimes parallelogram or heart-shape$ withsometimes parallelogram or heart-shape$ with

the widest measurement buccolinguallythe widest measurement buccolingually..

Prof. A. Elsahn

The mandibular molars are more oblong, The mandibular molars are more oblong,

rectangular or square with the widestrectangular or square with the widestmeasurement mesiodistally.measurement mesiodistally.


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+)+)

$i,e:$i,e:

'a%illary molars are the largest ma%illary'a%illary molars are the largest ma%illary

teeth.teeth. The second molar is smaller than the rst The second molar is smaller than the rst

in the same arch especially mesiodistally.in the same arch especially mesiodistally.

Third molars are generally the smallest. Third molars are generally the smallest.

The rst mandibular molars are the largest The rst mandibular molars are the largestmolar but the third molars may be eithermolar but the third molars may be either

larger or smaller than the second molars.larger or smaller than the second molars.Prof. A. Elsahn


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1-)1-)

#cclusion:#cclusion:

Each ma%illary molar occludes with theEach ma%illary molar occludes with the

corresponding mandibular molar and thecorresponding mandibular molar and thene%t more posterior molar e%ceptne%t more posterior molar e%ceptma%illary third molar which occludesma%illary third molar which occludesonly with the lower third molars.only with the lower third molars. Prof. A. Elsahn


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DescriptiveDescriptive

Anatomy ofAnatomy ofPermanentPermanent

Ma.illary MolarsMa.illary Molars

Prof. A. Elsahn

Ma.illaryMa.illary

!irst Molar!irst Molar


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nitial /alcicationnitial /alcication+irth or slightly+irth or slightlybeforebefore

/ompletion of crown/ompletion of crown ((0 1 ) years0 1 ) years

EruptionEruption 2 1 3 years2 1 3 years

/ompletion of roots/ompletion of roots 4 1 "5 years4 1 "5 years

C/#N#L#G0 C/#N#L#G0

Prof. A. Elsahn


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GeneralGeneral


".". t is the si%th tooth from the median line.t is the si%th tooth from the median line.

(.(. t is the largest tooth in the ma%illary arch.t is the largest tooth in the ma%illary arch.

Prof. A. Elsahn

""(())

&&

!!

22


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General CharacteristicsGeneral Characteristics

).). t has large crown with four well-formed cusps moret has large crown with four well-formed cusps more

pronounced than those on the opposing lowerpronounced than those on the opposing lower

molar$.molar$.

The two buccal cusps are more pointed The two buccal cusps are more pointed

than the two palatal cusps.than the two palatal cusps.Prof. A. Elsahn


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&.&. A unique feature of the tooth is the presenceA unique feature of the tooth is the presenceof an elevation calledof an elevation called tubercle of Carabellitubercle of Carabelli fth cusp$ on about 25 1 3! # of cases.fth cusp$ on about 25 1 3! # of cases.

Prof. A. Elsahn

G lG l


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GeneralGeneral


!.!. ts crown is wider buccolinguallyts crown is wider buccolinguallythan mesiodistally.than mesiodistally.

Prof. A. Elsahn

++

'' **


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2.2. t has three roots two buccal and onet has three roots two buccal and one

palatal as in all ma%illary molars.palatal as in all ma%illary molars.

Prof. A. Elsahn


+. Aspect+. Aspect . Aspect. Aspect


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he Cro'nhe Cro'n

uccaluccal

AspectAspect

The geometric outline of the The geometric outline of thecrowncrown is trape6oidal with theis trape6oidal with the

short of the uneven sidesshort of the uneven sides

cervically.cervically. Prof. A. Elsahn


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Distal outline:Distal outline:

Prof. A. Elsahn

s nearly straight from the cervicals nearly straight from the cervical

line to the mesial contact area, thenline to the mesial contact area, thencurves distally to be continuous withcurves distally to be continuous with

the mesial slope of the mesiobuccalthe mesial slope of the mesiobuccal

cusp.cusp.

MesialMesial

outline:outline:

s conve% from the cervical line tos conve% from the cervical line to

the tip of the distobuccal cusp.the tip of the distobuccal cusp.

ts ma%imum conve%ity is at thets ma%imum conve%ity is at thedistal contact area.distal contact area.

The distal side of the crown can be The distal side of the crown can be

seen from the buccal aspect due toseen from the buccal aspect due to

the obtuse distobuccal line angle.the obtuse distobuccal line angle.


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Contact Areas:Contact Areas:

M3$4ALM3$4AL

At the 7unction of the occlusal and middle third.At the 7unction of the occlusal and middle third.

D4$ALD4$AL

At the center of the middle third.At the center of the middle third.

Prof. A. Elsahn


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#cclusal #utline:#cclusal #utline:

Two buccal cusps, mesiobuccal Two buccal cusps, mesiobuccal

and dislobuccal cusps.and dislobuccal cusps.

Each cusp has a tip, a mesial cuspEach cusp has a tip, a mesial cusp

slope and distal cusp slope.slope and distal cusp slope.

The mesiobuccal cusp is broader The mesiobuccal cusp is broaderthan the distobuccal cusp.than the distobuccal cusp.

Prof. A. Elsahn


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The mesial and distal slopes of the The mesial and distal slopes of themesiobuccal cusp meet at an obtusemesiobuccal cusp meet at an obtuseangle, while the slopes of theangle, while the slopes of the

distobuccal cusp meet at rightdistobuccal cusp meet at rightangle, so the distobuccal cusp isangle, so the distobuccal cusp issharper and at least as long or oftensharper and at least as long or oftenlonger than the mesiobuccal cusp.longer than the mesiobuccal cusp.

Parts of the two lingual cusps can beParts of the two lingual cusps can beseen from the buccal aspect.seen from the buccal aspect.

Prof. A. Elsahn


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he Cervical Linehe Cervical Line

The cervical line is generally irregular The cervical line is generally irregular

and slightly conve% toward the root.and slightly conve% toward the root.

Prof. A. Elsahn


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Morpholo5y #f he uccalMorpholo5y #f he uccal

$urface #f he Cro'n:$urface #f he Cro'n: The buccal surface of the crown is The buccal surface of the crown is

conve%.conve%.

A buccal developmental grooveA buccal developmental groove

separates the two buccal cuspsseparates the two buccal cusps

e%tending to the middle third.e%tending to the middle third.

The groove fades out cervically, ending The groove fades out cervically, ending

by a transverse dip in enamel mesiallyby a transverse dip in enamel mesially

and distally. 8ometimes the buccaland distally. 8ometimes the buccalgroove ends by a pit.groove ends by a pit.

Prof. A. Elsahn


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The roots originate as a The roots originate as acommon undivided part oncommon undivided part onthe base of the crown, thisthe base of the crown, thissingle common root base issingle common root base iscalledcalled root trun6 root trun6 ..

The root trunk of this tooth The root trunk of this toothdivides into three roots9 twodivides into three roots9 twobuccal and one palatal. Thebuccal and one palatal. Thea%es of the roots area%es of the roots areinclined distally.inclined distally.

The length of root trunk is The length of root trunk isabout & millimeters.about & millimeters.

he ootshe ootshe ootshe oots

Prof. A. Elsahn


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The mesiobuccal root is slightly longer The mesiobuccal root is slightly longerthan the distobuccal one.than the distobuccal one.

:n the average, the length of the roots:n the average, the length of the rootsis about twice as long as the crown.is about twice as long as the crown.

he ootshe oots

Prof. A. Elsahn


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The mesiodistal diameter of the lingual The mesiodistal diameter of the lingual

surface is nearly equal to that of thesurface is nearly equal to that of the

buccal surface.buccal surface.

Lin5ual AspectLin5ual AspectLin5ual AspectLin5ual Aspect

Prof. A. Elsahn


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he Mesial #utline:he Mesial #utline: is almost straight and forms ais almost straight and forms aright angle with the mesialright angle with the mesial

slope of the mesiolingual cusp.slope of the mesiolingual cusp.

The two slopes of this cusp The two slopes of this cuspform an obtuse angle.form an obtuse angle.

he Distal #utline:he Distal #utline: is smoothly conve% andis smoothly conve% and

becomes continuous with thebecomes continuous with the

distal slope of the distolingualdistal slope of the distolingual

cusp cusp i.e.i.e. semicircular$semicircular$ Prof. A. Elsahn


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The two lingual cusps are the only The two lingual cusps are the only

one to be seen from this aspectone to be seen from this aspect

beside the cusp or tubercle ofbeside the cusp or tubercle of

/arabelli when e%ist$./arabelli when e%ist$. Prof. A. Elsahn


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he Mesiolin5ual Cusp:he Mesiolin5ual Cusp:

is the largest and longest cuspis the largest and longest cuspof this tooth.of this tooth.

ts mesiodistal width is aboutts mesiodistal width is about

three fth of the mesiodistalthree fth of the mesiodistal

crown diameter.crown diameter.

he Distolin5ual Cusp:he Distolin5ual Cusp:

is spheroidal and smooth.is spheroidal and smooth. t makes up the remaining twot makes up the remaining two

fth of the crown diameter.fth of the crown diameter.

Prof. A. Elsahn


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The fth cusp or tubercle of The fth cusp or tubercle of/arabelli is a small elevation,/arabelli is a small elevation,

commonly found in about 25commonly found in about 25per cent of cases on theper cent of cases on thelingual surface of thelingual surface of themesiolingual cusp.mesiolingual cusp.

t is outlined occlusally by ant is outlined occlusally by anirregular developmentalirregular developmentalgroove.groove.

f it is well developed, its cuspf it is well developed, its cuspridge is nearly ( mm cervicalridge is nearly ( mm cervicalto the cusp ridge of theto the cusp ridge of the

mesiolingual cusp.mesiolingual cusp. Prof. A. Elsahn


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Cervical Line:Cervical Line:

/ervical line is irregular./ervical line is irregular.

Prof. A. Elsahn


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Morpholo5y #f he Lin5ualMorpholo5y #f he Lin5ual

$urface:$urface: The lingual surface of the crown is The lingual surface of the crown isconve%.conve%.

A lingual developmental groove dividesA lingual developmental groove divides

unequally the two lingual cusps.unequally the two lingual cusps. t ends nearly at the center of thet ends nearly at the center of the

lingual surface.lingual surface.

;rom the end of the lingual groove a;rom the end of the lingual groove a

shallow depression e%tends to theshallow depression e%tends to thecenter of the lingual surface of thecenter of the lingual surface of thelingual root crossing the cervical linelingual root crossing the cervical lineand fades out at the middle third of theand fades out at the middle third of the

root.root. Prof. A. Elsahn

hh thh thh thh thh t


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he ootshe ootshe ootshe ootshe ootshe ootshe ootshe ootshe ootshe oots

The three roots are seen The three roots are seenlingually.lingually.

The large lingual palatal$ root The large lingual palatal$ rootis conical ending in a bluntlyis conical ending in a bluntly

rounded ape%. This ape% is on arounded ape%. This ape% is on a

line with the lingual groove.line with the lingual groove.

Parts of the buccal roots areParts of the buccal roots are

seen from this aspect behindseen from this aspect behind

the lingual onethe lingual one Prof. A. Elsahn


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Mesial AspectMesial Aspect

The geometric outline is The geometric outline is

roughly trape6oidal with theroughly trape6oidal with the

uneven short side occlusally.uneven short side occlusally.

;rom this aspect the great;rom this aspect the great

buccolingual dimension of thisbuccolingual dimension of thistooth is evident as in all uppertooth is evident as in all upper

molars.molars.

Prof. A. Elsahn


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uccal #utline:uccal #utline: 8tarting from the neck and ending at the8tarting from the neck and ending at the

tip of mesiobuccal cusp tip9 it is conve%,tip of mesiobuccal cusp tip9 it is conve%,then concave and nally slightly conve%.then concave and nally slightly conve%.

The crest of the cervical conve%ity is The crest of the cervical conve%ity islocated at the cervical third representinglocated at the cervical third representingthe ma%imum conve%ity of the cervicalthe ma%imum conve%ity of the cervicalridge.ridge.

The following concavity is shallow, The following concavity is shallow,representing the terminus of the buccalrepresenting the terminus of the buccaldevelopmental groove.developmental groove.

Then, the slight conve%ity circumscribed Then, the slight conve%ity circumscribedthe mesiobuccal cusp.the mesiobuccal cusp.

Prof. A. Elsahn


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Lin5ual #utline:Lin5ual #utline: ingual outline is smoothly conve% fromingual outline is smoothly conve% from

the cervical line to the mesiolingualthe cervical line to the mesiolingual

cusp tip if the tubercle of /arabelli iscusp tip if the tubercle of /arabelli is

undeveloped.undeveloped.

The crest of this conve%ity is at the The crest of this conve%ity is at the

middle third of the crown.middle third of the crown.

f the tubercle is well developed, thef the tubercle is well developed, the

lingual outline dips inward to illustratelingual outline dips inward to illustrateit.it.

Prof. A. Elsahn


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The tips of the two mesial cusps are within The tips of the two mesial cusps are within

pro7ected outlines of the root base.pro7ected outlines of the root base.

The mesiobuccal cusp is on a line with the The mesiobuccal cusp is on a line with the

long a%is of the lingual root.long a%is of the lingual root.

Prof. A. Elsahn



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The center of the occlusal The center of the occlusal

surface between the cusps is insurface between the cusps is inline with the root a%es as in allline with the root a%es as in all

ma%illary posterior teeth.ma%illary posterior teeth.

The mesial marginal ridge is The mesial marginal ridge isirregular and curving cervicallyirregular and curving cervically

about one-fth the crown length.about one-fth the crown length.

t is continuous with the cuspt is continuous with the cusp

ridges of the two mesial cusps.ridges of the two mesial cusps.

Prof. A. Elsahn


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he Cervical Line:he Cervical Line:

The cervical line is irregular and slightly The cervical line is irregular and slightly

conve% occlusally.conve% occlusally.Prof. A. Elsahn


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Morpholo5y #f heMorpholo5y #f he

Mesial $urface:Mesial $urface: The mesial surface is almost The mesial surface is almost


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Morpholo5y #f he MesialMorpholo5y #f he Mesial

$urface:$urface: A shallow concavity isA shallow concavity is

usually found 7ust belowusually found 7ust below

the mesial contact area.the mesial contact area.

This concavity may e%tend This concavity may e%tend

to the mesial surface ofto the mesial surface ofthe root trunk at itsthe root trunk at its

cervical third.cervical third.

Prof. A. Elsahn


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he ootshe ootshe ootshe ootshe ootshe oots

he oot run6 he oot run6

is a little shorter mesially thanis a little shorter mesially thanbuccally about ) mm$ with abuccally about ) mm$ with a

smooth depression at thesmooth depression at thebifurcation e%tending occlusally andbifurcation e%tending occlusally and

lingually.lingually.

he Mesiobuccal oothe Mesiobuccal oot

is broad and


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he Palatal oothe Palatal oot is longer and narrower than theis longer and narrower than the

mesiobuccal root.mesiobuccal root. The palatal root is the most divergent root The palatal root is the most divergent root

in order to follow the bone around thein order to follow the bone around the

ma%illary sinus.ma%illary sinus.

t ist is banana7shape8banana7shape8 , e%tending lingually., e%tending lingually.

he Distobuccal oothe Distobuccal oot can not becan not be

seen from this aspect.seen from this aspect.

t is hidden behind the mesiobuccal one.t is hidden behind the mesiobuccal one.

Prof. A. Elsahn

Distal AspectDistal Aspect


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Distal AspectDistal Aspect

t is similar to the mesial aspectt is similar to the mesial aspectwith certain variations.with certain variations.

The crown tends to converge The crown tends to converge

distally, due to the slant of thedistally, due to the slant of the

buccal side.buccal side.

8o, the buccolingual measurement8o, the buccolingual measurementof the crown distally is smaller thanof the crown distally is smaller than

that mesially, thus part of thethat mesially, thus part of the

buccal surface can be seen distally.buccal surface can be seen distally.

Prof. A. Elsahn


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The distal surface of the crown is The distal surface of the crown is

generally conve% e%cept for agenerally conve% e%cept for a

small concave area at thesmall concave area at thecervical third near thecervical third near the

distobuccal root.distobuccal root.

This area e%tends to the distal This area e%tends to the distal

surface of the distobuccal root upsurface of the distobuccal root up

to the furcation area.to the furcation area.

The distal marginal ridge is more The distal marginal ridge is more

curved cervically, e%posing partcurved cervically, e%posing part

of the occlusal surface distally.of the occlusal surface distally.

Prof. A. Elsahn


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he Cervical Linehe Cervical Line

s almost straight.s almost straight.

:ccasionally it may curve apically.:ccasionally it may curve apically.

Prof. A. Elsahn


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he ootshe oots

The root trunk shows the The root trunk shows thelargest length distallylargest length distally

reaching ! mm or more.reaching ! mm or more.

The distobuccal root is The distobuccal root is

narrower than the othernarrower than the other

two roots.two roots.

Prof. A. Elsahn

# l l A t# l l A t


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#cclusal Aspect#cclusal Aspect

The geometric outline of The geometric outline ofthe crown occlusally isthe crown occlusally is

somewhat rhomboidalsomewhat rhomboidalwith acute mesiobuccalwith acute mesiobuccaland distolingual anglesand distolingual angles

and obtuse mesiolingualand obtuse mesiolingual

and distobuccal angles.and distobuccal angles.

Prof. A. Elsahn


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The buccolingual measurement of the crown mesially is The buccolingual measurement of the crown mesially isgreater than distally.greater than distally.

The mesiodistal measurement lingually is greater than The mesiodistal measurement lingually is greater thanbuccally.buccally.

Thus, Thus,

The crown is wider mesially than distally and wider lingually The crown is wider mesially than distally and wider linguallythan buccally, due to buccal convergence of the distal surface.than buccally, due to buccal convergence of the distal surface.

Prof. A. Elsahn


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The ma%illary rst molar has four The ma%illary rst molar has four

well developed cusps namedwell developed cusps named

according to their location.according to their location.

A small fth cusp or tubercle ofA small fth cusp or tubercle of

/arabelli appearing on the/arabelli appearing on the

lingual surface of thelingual surface of the

mesiolingual cusp near themesiolingual cusp near the

mesiolingual line angle.mesiolingual line angle.

This tubercle may be ill dened This tubercle may be ill dened

or absent.or absent.

Prof. A. Elsahn


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The mesiolingual cusp is the largest The mesiolingual cusp is the largestfollowed in decreasing order of si6e by thefollowed in decreasing order of si6e by the

mesiobuccal, distolingual in 3(# andmesiobuccal, distolingual in 3(# and

distobuccal cusp in "=# of the cases.distobuccal cusp in "=# of the cases.

The fth cusp tubercle$, if present, is the The fth cusp tubercle$, if present, is the

smallest.smallest. Prof. A. Elsahn

i8i8


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i85es:i85es:

Each of the four cusps has a denite triangularEach of the four cusps has a denite triangularridge.ridge.

>nion of the triangular ridges of the>nion of the triangular ridges of themesiolingual and the distobuccal cusps formsmesiolingual and the distobuccal cusps forms

anan obli9ue ri85eobli9ue ri85e crossing the occlusal surfacecrossing the occlusal surfaceobliquely characteristic of ma%illary molars$.obliquely characteristic of ma%illary molars$.

This ridge is reduced in height in the center of This ridge is reduced in height in the center of

the occlusal surface.the occlusal surface. Prof. A. Elsahn


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i85es:i85es:

The mesial and distal The mesial and distal mar5inal ri85esmar5inal ri85es are continuous with the ad7acent cuspare continuous with the ad7acent cusp

ridges.ridges.Prof. A. Elsahn

!


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!ossae!ossae

here are two ma7or fossae?here are two ma7or fossae?

he central fossaehe central fossaehe 8istal fossaehe 8istal fossae

And two minor fossae?And two minor fossae?he mesial trian5ular fossaehe mesial trian5ular fossae

he 8istal trian5ular fossaehe 8istal trian5ular fossae

Prof. A. Elsahn


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he Central !ossahe Central !ossa t is roughly large triangulart is roughly large triangular

concave area.concave area.

t is near the center of the occlusalt is near the center of the occlusal

surface, and mesial to the obliquesurface, and mesial to the oblique

ridge.ridge.

t is bounded by the oblique ridget is bounded by the oblique ridge

and the distal and mesial slopes ofand the distal and mesial slopes of

the mesiobuccal and distobuccalthe mesiobuccal and distobuccal

cusps respectively.cusps respectively. The central fossa contains in its The central fossa contains in its

depth a central developmental pit.depth a central developmental pit.

Prof. A. Elsahn


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he Distal !ossahe Distal !ossa

The distal fossa is roughly elongated The distal fossa is roughly elongated

and distal to the oblique ridge.and distal to the oblique ridge.Prof. A. Elsahn


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The small mesial and the minute distal The small mesial and the minute distaltriangular fossae are immediately distaltriangular fossae are immediately distal

and mesial to the mesial and distaland mesial to the mesial and distal

marginal ridges respectively .marginal ridges respectively . Prof. A. Elsahn

DevelopmentDevelopment


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DevelopmentDevelopment

al Groovesal Grooves

8tarting from the central pit of the central8tarting from the central pit of the central

fossa the following grooves radiate?fossa the following grooves radiate?

The The buccal 8evelopmental 5roovebuccal 8evelopmental 5roove e%tendse%tends

from the central pit buccally and continuesfrom the central pit buccally and continues

between the buccal cusps onto the buccalbetween the buccal cusps onto the buccal

surface of the crown as the buccal groove.surface of the crown as the buccal groove.

8tarting from the central pit of the central8tarting from the central pit of the central

fossa the following grooves radiate?fossa the following grooves radiate?

The The buccal 8evelopmental 5roovebuccal 8evelopmental 5roove e%tendse%tends

from the central pit buccally and continuesfrom the central pit buccally and continues

between the buccal cusps onto the buccalbetween the buccal cusps onto the buccal

surface of the crown as the buccal groove.surface of the crown as the buccal groove.Prof. A. Elsahn

he Central Groovehe Central Groove


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he Central Groovehe Central Groove

The central groove e%tends mesially The central groove e%tends mesially

from the central pit to terminate atfrom the central pit to terminate at

the ape% of the mesial triangularthe ape% of the mesial triangular

fossa.fossa. Prof. A. Elsahn


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#ccasionally#ccasionally, a short, a shortdevelopmental groovedevelopmental groove

radiates from the central pitradiates from the central pitand runs transversely andand runs transversely anddistally across the obliquedistally across the obliqueridge to the distal fossaridge to the distal fossa

7oining the central and distal 7oining the central and distalfossae.fossae.

This groove is called the This groove is called thetransverse 5roovetransverse 5roove, of the, of theoblique ridge.oblique ridge.

Prof. A. Elsahn

he Distal #bli9uehe Distal #bli9ue


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t is irregular developmental groovet is irregular developmental groove

traverses the distal fossa from the distaltraverses the distal fossa from the distaltriangular fossa lingually between thetriangular fossa lingually between thelingual cusps and continues onto thelingual cusps and continues onto thelingual surface as the lingual groove.lingual surface as the lingual groove.


Groove:Groove:

Prof. A. Elsahn

h !if h C Gh !ifth C G


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lf the fth cusp groove or tubercle$ islf the fth cusp groove or tubercle$ isdistinct, this groove separates thedistinct, this groove separates the

tubercle from the mesiolingual cusp andtubercle from the mesiolingual cusp and

7oins the lingual groove. 7oins the lingual groove.

he !ifth Cusp Groove:he !ifth Cusp Groove:

Prof. A. Elsahn

GG


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GroovesGrooves

GroovesGrooves

At the ape% of the mesialAt the ape% of the mesialtriangular fossa,triangular fossa,

supplemental groovessupplemental grooves

radiate as branches fromradiate as branches fromthe terminus of the centralthe terminus of the central

groove into the triangulargroove into the triangular

fossa.fossa.

#ccasionally#ccasionally one or moreone or more

supplemental grooves crosssupplemental grooves cross Prof. A. Elsahn



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GrooveGroove

t shows several supplemental grooves.t shows several supplemental grooves.

This developmental groove terminates This developmental groove terminates

distally in the distal triangular fossa by twodistally in the distal triangular fossa by two

terminal branches that form the two sides ofterminal branches that form the two sides of

Anatomy of Peremanent Molars

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