THE MOLARS:

How to differentiate between upper and lower molar?

LET'S GO >>

1. THE MAXILLARY MOLARS :

**maxillary molars have 3 roots (MB root, DB root, L root)

.which is running from ML cusp to DB cusp oblique ridgethe **

The largest cusp [mesiolingual in the lower right here] is connected diagonally to the cusp in the opposite corner by an

found only oblique ridgeon MAXILLARY molars.

**maxillary molars are wider Buccolingually than Mesiodistally ( BL dimension > MD dimension).

THE MANDIBULAR MOLARS:

**the mandibular molars have 2 roots (mesial and distal roots).

**there is no oblique ridge for any mandibular molars.

** mandibular molars are wider mesiodistally than buccolingually (MD dimension > BL dimension).

This is the occlusal view of a MANDIBULAR molar.This is the only tooth to have 3 cusps in a row on one side [the facial side], and 2 cusps on the other side.

How to differentiate between the types of molars )??rd,3nd, 2st(1

MAXILLARY 1ST MOLARE:

**The maxillary first molar is the only tooth with 4 cusps of unequal size AND, most often, one small minor (functionless) cusp [of Carabelli] seen on a surface of the largest cusp [mesiolingual on the lower right of this

tooth].

This is a maxillary FIRST molar. Many maxillary first

molars have a small, short cusp of Carabelli located on the lingual surface of the largest mesiolingual cusp. Also, the root are more divergent (spread out more).

istal side of the How to differentiate between the mesial and dteeth??

**The mesial cusps are larger and somewhat longer than the distal

cusps. Also, of the two facial roots, the mesial root is longer.

MAXILLARY 2ND MOLAR:

** The maxillary SECOND molar has roots that converge, and have no cusp of Carabelli.

MANDIBULAR 1ST MOLAR:

**more likely to have 5 cusps: 3 on one side [the facial] and 2 on the other [lingual]. Also, the roots are more divergent on the mandibular first molar.

How to differentiate between the mesial and distal side of the teeth??

than the distal cusp (and the distal longer**The mesial cusp is clearly "see the pic. above" .smallest)cusp is clearly the

MANDIBULAR 2ND MOLAR:

**has 4 cusps: 2 buccal (visible from this facial view) and 2 lingual (not visible here), and 2 roots that are not well separated).

first molars may have only 2 facial some mandibular NOTE!!cusps, but the two roots on the first molar would be more separated.

How to differentiate between the mesial and distal side of the

teeth??

**The mesial cusp is larger and longer than the distal. Also, the bend of

. (Mesial roots are usually distalmolar roots is normally toward the longer, but not here.) "see the pic. above"

THE MAXILLARY 3RD MOLAR:

"the Dr doesn't mention any thing about this tooth so you can return to slides,, but here there are some pictures to help you"

THE MANDIBULAR 3RD MOLAR:

**the roots are distally inclined ,, as we go from 1st to 3rd the roots become distally

inclined.

**The mandibular 3rd molar it's very irregular in shape so it's possible to see 4 cusps to be smilar to a mandibular second molar, also it may have 5 cusps to be similar to a mandibular 1st molar and it's possiple to have 6 cusps, it's distally inclined root, and the mesial HOC is higher than the distal HOC.

THE PREMOLARS,,

The most difficult point is >> how to differentiate between

the upper and lower premolars!?

Don't worry it will be easy,, let's start :D

1. THE MAXILLARY PREMOLARS :

** the long axes of the crown of upper premolars is in lined with the long axes of the root.

NOTICE>> It has the crown and cusps lined up over the root (as seen on the diagram).

**from the occlusal surface the maxillary premolars BL dimension is longer than MD dimension .

This is a MAXILLARY premolar because it is relatively rectangular (or oval) with the longest dimension from facial to lingual [top to bottom

here].

2. THE MANDIBULAR PREMOLARS :

** the long axes of the crown of lower premolars aren't in lined with the long axes of the root. The crown is tilted lingually,, so the long axes of the crown passes throw the tip of the buccal cusp.

A MANDIBULAR premolar (proximal view) would have the crown tipped to the lingual relative to the root axis as on this mandibular premolar (diagramed on the left).

**the BL dimension it's almost equal to MD dimension.

A MANDIBULAR premolar outline would be much more square or round or diamond shape

How to differentiate between the types of "?? ndand 2 stpremolars " 1

THE MAXILLARY 1st PREMOLAR:

**The maxillary FIRST premolar is more likely to have two roots, but even if it has only one root, there is a cavitation on

.mesial crown cavitationthe root that is continuous with a

** the occlusal outline is more asymmetrical compared to the second premolar and the central groove appears quite long.

How to differentiate between the mesial and distal side of the teeth??

**he lingual cusp tip [lower cusp on these teeth] is "bent" more toward the mesial making the mesial outline flatter (or even concave) compared to the distal.

**The mesial crown surface of the maxillary first premolar is the only premolar surface where the root concavity is continuous with a cervical crown concavity.

THE MAXILLARY 2ND PREMOLAR:

mesial crown NOwith This second premolar has one root**cavitation continuous with a root cavitation.

**The occlusal outline is almost smoothly oval with a very short central groove and many supplemental grooves (a wrinkled

surface).

How to differentiate between the mesial and distal side of the

teeth??

**As on most premolars, the lingual cups tip [lower cusp here] is

positioned more to the mesial making the mesial crown outline

appear slightly flatter than the distal.

THE MANDIBUALR 1ST PREMOLAR:

**This tooth is diamond shaped from the occlusal view with one

"wall" [the mesiolingual corner or lower left wall here] quite

flattened or almost concave. Also, the two occlusal pits are very

prominent without a prominent connecting central groove.

** there is a groove between the mesial marginal ridge and the L cusp so it's called the mesiolingual groove,, it's only found mesially so the simplest way to determine the mesial side is to look for this groove also the mesial marginal ridge is lower than the distal marginal ridge "it's an exception". "the

mesial side here on your right"

THE MANDIBULAR 2ND PREMOLAR:

**The occlusal outline of a mandibular SECOND premolar would

be more square (if it were the three cusp type as on the left

drawing) or more rounded if it were the 2 cusp type of second

premolar.

How to differentiate between the mesial and distal side of the

teeth??

**On the 2-cusped type the lingual cusp tip [lower cusp here] is

more mesial than the facial cusp tip.

**On the 3-cusped type, the mesio-lingual cusp [lower right

corner] is larger (and longer) than the disto-lingual cusp [lower left

corner].

REFRESH YOUR MIND,, :D

Be calm everything will be ok,, just if you imagine the pictures above..:0

1. maxillary molars have angles that aren't right angles they look

rhomboidal in shape, we have acute angles and obtuse angles.

2. As we go from first to third molar the roots become close to each other and more distal inclined ,, the size of DL cusp decreases AND commonly missed in maxillary 3rd molar,, so there will be one cusp lingually called lingual cusp ALSO the amount of acuteness and obtuseness increases "the angles become more prominent" for example the ML angle is very acute in 3rd molar whereas it's less acute in first 1st molar.

3. In the upper molars the biggest cusp is ML then MB then DB then DL and

the order of decrease in size is clock wise if we talk about left teeth and counter clock wise if we talk about right teeth.

4. in maxillary molars It's easy to identify the buccal side because there is 2 buccal roots but the lingual side has on root ,, notice buccally we have the buccal groove that extend buccally ,and lingually we have lingual groove that extends as distolingual groove ,remember the oplique ridge,, also the transverse ridge,, and notice between the oplique and transverse ridges there is a central fossa,, between the transverse and mesial triangular ridges

there is a mesial triangular fossa,, between the oblique ridge and the distal

marginal ridges on the buccal part there is a distal triangular fossa and on the lingual part there is a mesial triangular fossa..

5. Mandibular molars are characterized by cusps with an equal size,, there is no oblique ridge but with 2 transverse ridges,, one from MB to ML anther one from DB to DL cusp,, there are 3 fossae one mesial side called mesial triangular fossa witch is located between mesial transverse ridge and mesial

marginal ridge , one on distal side called distal triangular fossa which is located between distal marginal ridge and distal transverse ridge and one central fossa witch is located between the 2 transverse ridges.,,

6. The mandibular 1st molar without the small distal cusp it looks like rectangular in shape but with addition of small distal cusp it looks different ,, the two profiles mesial and distal are convergent mesially,, but in mandibular 2nd molar there are only 4 cusps,, so it much easier to identify,, it has 2 roots one mesial another distal.. with 4 cusps almost equal in size,, the

buccal side always inclined lingually and the buccal HOC is near to cervical line and the lingual HOC is near to the occlusal line.

7 the cusps that participate in the occlusion are the buccal cusp of mandibular and lingual cusp of maxillary so the lingual cusp in mandibular teeth is higher than the buccal cusp, and it's the opposite for the maxillary teeth "the higher will be the buccal cusp".

8. we can determine the distal side of the molars according to the inclined of the root which is go distally, also according to the prominence of the

always the mesial marginal ridge is higher than : uleThe R .marginal ridge

the distal marginal ridge. according to that the mesial HOC also will be higher than distal HOC except for the mandibular 1st premolar it just the opposite.

9. In maxillary 2nd premolar there is no groove crossing the mesial marginal ridge,,

10. It's more common for maxillary 1st premolar to see 2 roots,, and more common for maxillary 2nd premolar to see 1 root,, but don't depend on these feature to distinguish between them 100% because there is a possibility for a maxillary 1st premolar to have 1 root,, and for maxillary seconed to have 2 roots,,

11. The canine fossa it's located on the mesial side of the 1 st premolar.

12. In Maxillary 2nd premolar the 2 cusps are equal in size,, but in the 1 st premolar they aren’t equal in size>> the buccal cusp is higher than the lingual cusp,,

13. In the mandibular 2nd premolar to know where the right and left side simply the mesial marginal ridge is higher than the distal marginal ridge..

14. In the mandibular 2nd premolars the 2 marginal ridges are the same, and the mesial and distal profile almost parallel to each other,, also there is too many supplemental grooves and the central groove is short,

15. In Mandibular 1st premolar,, the 2 cusps are very different in size,, the buccal cusp is very big and the lingual cusp is very small.

16. In Mandibular 2nd premolar it's more common to see two cusps lingually>> ML and DL cusps.

OU READY WE WILL PLAY NOW,, ;DARE Y

Identify these teeth :PpP..

1. 2.

3. 4.

1. maxillary 2nd premolar

2. maxillary 1st molar

3. mandibular 2nd premolar

4. maxillary 1st premolar

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اللهم آت نفسي تقواها ، وزكها يا خير من زكاها ، أنت ..وليها و موالها يا رب العالمين

DONE BY: Heba ALaZzam…