(oral ana) max 3rd molars

8/4/2019 (Oral Ana) Max 3rd Molars

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Maxillary Third Molars



RIGHT THIRD

MOLARLEFT THIRDMOLAR

PALMERS 8┙ ┗8

UNIVERSAL 1 16

2-DIGIT 18 28



CALCIFICATION ANDERUPTION Years

FIRST EVIDENCE OF

CALCIFICATION

7-9

ENAMEL COMPLETED 12-16

ERUPTION 17-21

ROOT COMPLETED 18-25



Often called wisdom teeth because they erupt when theyoung adult is passing into manhood or womanhood

Often appears as a developmental anomaly

Vary considerable in size, contour, and relative position to theother teeth



Crown is shorter cervico-occlusallyand narrower mesiodistally

D M



D M

Mesiofacial cusp width mesiodistally is

proportionately wider when comparedto the width of distofacial cusp



D M

Roots are usually fused,

functioning as one large root, andthey are shorter cervicoapically



D M

Fused roots end in a taper at the

apex



D M

Roots have a distinct slant to the

distal, giving the apices of thefused root a more distal relation tothe center of the crown



D

Only one large lingual cusp is

present, and therefore no lingualgroove is evident

M D



D

Other maxillary third molar:

M D

The mesiolingual cusp tip is morecentered mesiodistally.

The mesiolingual cusp dominates themesiodistal width of the crown

Often the distolingual cusp is so short,narrow and rounded that the lingualgroove is evident as a mere fold in theenamel and the cusp seems to havelittle height at all

Difference in root curvature anddivergence



D


M D







DM D

Taper to the fused roots and a

bifurcation usually in the region ofthe apical third

L F



DM D

L FF L

More of the occlusal surface maybe seen from this aspectbecause of the more acuteangulation of the occlusal

surface in relation to the longaxis of the root

Measurement from thecervical line to the marginal

ridge is short



DM D

L FF L

From the occlusal view, the crown

outline is described as heart shaped

D M

The occlusal anatomy is similar to that of other maxillary molars. This is particularlytrue of the Primary Cusp Triangle (Trigon)area. The distolingual cusp and distalmarginal ridge will be dissimilar in thefollowing ways:

The distolingual cusp will be shorter andnarrower (mesiodistally).The distal outline will be more rounded.It is often difficult to distinguish definite,separate cuspal and triangular ridges on thedistolingual cusp.Often, the distolingual cusp is seen as onlya minor elevation or “Talon”. Often, the distal marginal ridge is hardlydiscernible.Likewise, definite lingual, distal oblique anddistolingual grooves are hard to distinguish.Often, this whole area of the crownbecomes a single convex roll of enamelfrom the crest of the oblique ridge onto the

distal surface.



DM D

L FF L



D M

The occlusal anatomy is similar to that of other maxillary molars. This is particularlytrue of the Primary Cusp Triangle (Trigon)area. The distolingual cusp and distalmarginal ridge will be dissimilar in thefollowing ways:

The distolingual cusp will be shorter andnarrower (mesiodistally).The distal outline will be more rounded.It is often difficult to distinguish definite,separate cuspal and triangular ridges on thedistolingual cusp.Often, the distolingual cusp is seen as onlya minor elevation or “Talon”. Often, the distal marginal ridge is hardlydiscernible.Likewise, definite lingual, distal oblique anddistolingual grooves are hard to distinguish.Often, this whole area of the crownbecomes a single convex roll of enamelfrom the crest of the oblique ridge onto the

distal surface.



DM D

L FF L



D M

The occlusal anatomy is similar to that of other maxillary molars. This is particularlytrue of the Primary Cusp Triangle (Trigon)area.The distolingual cusp and distal marginalridge will be dissimilar in the following

ways:

The distolingual cusp will be shorter andnarrower (mesiodistally).

The distal outline will be more rounded.Often, the distal marginal ridge is hardly

discernible.

Likewise, definite lingual, distal oblique anddistolingual grooves are hard to distinguish.

Often, this whole area of the crownbecomes a single convex roll of enamel

from the crest of the oblique ridge onto thedistal surface.



DM D

L FF L

From the occlusal view, the crownoutline is described as heart shaped

D M

The occlusal anatomy is similar to that of other maxillary molars. This is particularlytrue of the Primary Cusp Triangle (Trigon)area.The distolingual cusp and distal marginalridge will be dissimilar in the followingways:

The distolingual cusp will be shorter andnarrower (mesiodistally)

The distal outline will be more rounded.

Often, the distal marginal ridge is hardly

discernible.






DM D

L FF L


D M





discernible.






DECIDUOUS MAXILLARY

1ST

MOLAR



o Most atypical of all primary or permanentmolars : it looks diff. n very atypical, doesn’t

look likepremolar or molar.

o Intermediate between a premolar & a molar :

it is someway intermediate between premolarandmolar.

o Smallest molar in all deciduous: everydimension is the smallest except the BLdiameter.



RIGHT FIRST MOLAR LEFT FIIRST

MOLAR

PALMERS D D

UNIVERSAL B I

2-DIGIT54 64



CALCIFICATION AND ERUPTION

Hard Tissue Formation 15 ½ weeks

ENAMEL COMPLETED 6 months

ERUPTION(13-19)boys(14-18) girls

ROOT COMPLETED 2 ½ years



Buccal Aspect

o Mesial part is higher OC thanDistal because its moreprojected cervically onto theroot area

o bigger distance that thecervical line goes apicallythan mesially .

o

Marked cervical constriction.That means the cervical ismore constricted



Lingual Aspect

o Mesiolingual cusp ismore prominent

o The distolingual cusp ispoorly defined

o distobuccal cusp islonger and betterdevelop

o The lingual root islonger



Mesial Aspect

o Cervical third is greaterthan the occlusal third(dimension)

o Mesiolingual cusp islonger and sharper thanthe mesiobuccal cusp

o Pronounced convexity on

the buccal outlineo The mesiobuccal roots

and lingual roots arevisible



Occlusal Aspect

Trapezoidal : the occlusal shapeis trapezoidal

M & D profiles are straight &slightly L convergent

o B cusp > L : Buccal cusp isbigger than the lingual cusp

Buccal triangular ridge more

prominent than L : buccal one isbigger than lingual one B groove separates DB cusp

from MB : Buccal developmentalgroove

separates between MB n DBcusp. Not located at mid portionof crown

MD.Located closer to the distalpart of crown.why? because theMB cusp is

bigger



Central pit : B groove ends in

mid portion of crown. At the endwe have

Central groove : start from M pit

to D pit Transverse ridge or oblique

ridge? between B groove & D MR: in max

molars. We know that oblique

ridge runs from tip of ML cusp totip of DB. H-shaped pit/groove pattern :

groove pattern is H shaped we have Central groove We have Triangular

supplemental grooves: attriangular fossa

M & D marginal grooves :crossing the mesial and distalmarginal ridges



Deciduous Maxillary2nd Molar



RIGHT FIRST MOLAR LEFT FIIRSTMOLAR

PALMERS E E

UNIVERSAL A J

2-DIGIT55 55



Morphologically considered a model for the

permanent 1st maxillary molar : this tooth exactly looks like the that erupts behind it.

What is the tooth? Permanent

Max. 1st molar. To differentiates between them is

to use only the set traits. The similarity btwn the anatomy is called isomorphy.

The tooth look alike. but the tooth doesn’t likethe tooth that replace it.

If the 2nd deci max molar has a very prominentcusps of carebelli, the 1st parm. Max molar willalso have the same prominent cusps of carebelli.



Set traits

Cervical constriction Cervical 1/3 bulging

Little root trunk

Roots thinner

(oral ana) max 3rd molars

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