morpho lab

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TOOTH IDENTIFICATION

This topic accounts for about%07 of the practical exam

It's very important for you to know the steps that you have to follow allthe time to identify the tooth, so what are these steps ??1. You have to identify the set of the tooth

Regarding the set, the tooth is either permanent or deciduous

Here you have to use the set traits

What are the set traits that may help you distinguish permanent toothfrom deciduous tooth ??

a. Size

Permanent teeth are larger in size than deciduous teeth (i.e.permanent central incisor is larger than primary central incisor)

b. Color

Deciduous teeth are lighter in color than permanent teeth that's why

they (deciduous teeth) are called milk teeth

c. Cervical constriction

Exists in deciduous but not in permanent

d. Amount of root trunk in molars

Very little in deciduous but long in permanent (the furcation beginsvery cervically in deciduous molars)

e. Amount of root divergence

The roots are very divergent and flared out in deciduous and very thinalso

2. You have to identify the class of the tooth

Regarding the class, the tooth is either an incisor, c-*--anine, premolaror molar

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Here you have to use the class traits*** There's NO premolars in the deciduous dentition

3. You have to identify the arch of the tooth

tooth is either maxillary or mandibularRegarding the arch, the

Here you have to use the arch traits

4. You have to identify the type of the tooth

i.e. If the tooth is a molar, then is it a first , second or a third molar?

If the tooth is a premolar, then is it a first or a second premolar?If the tooth is an incisor, then is it a central or a lateral incisor?

Here you have to use the type traits

*** Canines have NO type traits

5. You have to identify the side of the tooth (the most important)

Regarding the side, the tooth is either from the right side or the leftside of the mouth

** How can we know whether the tooth is a right or a left tooth??

>>> You have to identify all the aspects of the tooth

For post. teeth the occlusal aspect is the one that can tell you the mostabout the side of the tooth

For ant. teeth the labial aspect is the one that can tell you the mostabout the side of the tooth

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Labialaspect

Incisal aspect

*** Questions :

*** Can you identify this tooth ??

* First, you have to identify the set of the tooth>>> Regarding the size it is a permanent tooth

* Second, you have to identify the class of the tooth

>>>

* From the labial aspect :This tooth has an incisal edge that is flattened MD

* From the incisal aspect :

1. This tooth has long horizontal biting edgethat is compressed LL2. This tooth has 3 mamelons

All these tell you that the tooth is an incisor* Third, you have to identify the arch of thetooth

>>>1. The crown is wide MD

2. MD dimension of the crown is slightly smallerthan the IC dimension (height/width proportionis very small)3. MD dimension of the root = LL dimension4. The labial surface is rounded as seen from theincisal aspect

So >>> The arch of this tooth is the maxillary arch

* Forth, you have to identify the type of the tooth

>>>From the labial aspect :1. the crown of the tooth is very wide MD2. the MI and DI angles aren't that much rounded (MI angle is sharp)3. the root is conical in shape

From the lingual aspect :

Proximalaspect

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1. M and D marginal ridges, cingulum and lingual fossa all these aren'tthat much pronounced2. NO lingual pit

All these tell you that the tooth is a central incisor* Fifth, you have to identify the side of the toothIn maxillary central incisors :1. the MI angle is sharp (0 degrees) while the DI angle is rounded2. the M outline is straight while the D outline is rounded3. the MI angle is higher (more toward the incisal edge) than the DIangle4

. you can use the M and D HOCs also (MHOC is higher than the DHOC)5. Very very important point: always remember that the M outline isinlined with the outline of the root while the D outline isn't inlined withthe outline of the root, it is located outside the outline of the root.

oneleftthetooth isside of theheT>>>So

So >>>>> the tooth is maxillary left permanent central incisor (21)

If you want to place it in the mouth then :

Rounded

DI angle

Rounded

D outline

Sharp

MI angle

Stright Moutline

DHOCMHOC

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*** Can you identify this tooth ??1. What is the set of the tooth??

Regarding the size this tooth is a permanenttooth

2. What is the class of the tooth??

> It has only one conical pointed cusp>> It doesn't have an occlusal surface>>> As seen from the proximal aspect it'sroot is very thick LL>>>> It has a well developed cingulum(that's why it can't be a premolar)

>>>>> It has 2 well developed depressions(Mesio-labial and Disto-labial) on the labial surfaceSo >>>>The class of the tooth is a canine

3. What is the arch of the tooth??

> Notice the overhanging of the proximal outlines (how

they are located outside the root)

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>> As seen from the proximal aspect notice that the cusp tip islocated labial to the LL bisecting line (this point is very importantand critical in the differentiation btwn max. and mand. canines)>>> MD dimension > IC dimension of the crown

>>>> As seen from the lingual aspect, the cingulum is veryprominent, M and D marginal ridges are prominent also, the ML andDL fossae are very deep and the lingual pit is apparent>>>>> M and D outlines are markedly convergent towardthe cervix>>>>>> You can sometimes depend on the position of HOCs whichare relatively lower in maxillary than in mandibular

All these tell you that this canine is from the maxillary arch

4. What is the type of the tooth?? Canines have NO type traits

5. What is the side of the tooth?? > MSR (mesial sloping ridge) is shorter than the DSR>> MI angle is higher and more rounded than the DIangle>>>You can also identify the side of the tooth from the incisalaspect, notice the amount of asymmetry btwn the M and D halves,the D half is wider than the M half (D half is thick MD and thin LL,while the M half is thin MD and thick LL) and by this you can knowwhich is the M side and which is the D side

WiderD half

SmallerM half

DLfossa

MLfossa

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Based on these : the side of the tooth is the right one

So >>>> The tooth is maxillary right permanent canine (13)

** Can you identify this tooth??1. What is the set of this tooth?? (is it permanent ordeciduous ??)

> It is large in size>> This tooth is natural, and it isn't very white in colorand this somehow excludes being deciduous>>> We don't see any cervical constriction at the area

btwn the crown and the root portions of the tooth

So >>> The set of this tooth is permanent

2. What is the class of the tooth?? (is it incisor, canine, premolar ormolar ??)

> This tooth has a biting edge that is flattened MD and compressed

LL>> As seen from the incisal aspect, this tooth has 3 mamelons

So >>> The class of this tooth is incisor

3. What is the arch of this tooth?? (is it max. or mand. Incisor??)

> The crown is wide MD>> MD dimension of the crown is slightly smaller than the

IC dimension (height/width proportion is very small)>>> MD dimension of the root = LL dimension (veryimportant)>>>> The labial surface is rounded as seen from theincisal aspect

So >>> The tooth is a maxillary incisor

4. What is the type of the tooth?? (is it max. central or max. lateralincisor??)

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Slightly roundedMI angle

Markedlyrounded DI angle

> The crown outlines are very rounded and the crownisn't that much wide MD>> MI and DI angles are very rounded (MI angle isn'tsharp)>>> As seen from the lingual aspect, the M and Dmarginal ridges are very prominent, the cingulum is veryconvex and prominent, the lingual fossa is very deep andhas a pit>>>> The root isn't1007 conical (remember that incentral incisors the root is 1007 conical)

So >>> The type of the tooth is

incisorlatera

5. What is the side of the tooth??(is it a right or a left max. lateral incisor??)

> DI angle is markedly rounded while the MI angle isslightly rounded>> MHOC is higher than the DHOC (MI angle is higherthan the DI angle)

>>> M outline is slightly rounded while the D outline ismarkedly rounded>>>> M outline is inlined with the outline of the rootwhile the D outline isn't inlined with the outline of theroot, it is located outside the outline of the root.

So >>> The side of the tooth is the left side

The tooth is maxillary left permanentlateral incisor

*** Can you identify this tooth??1. This tooth is a permanent tooth

2. What is the class of the tooth??

Very convexcingulum

Very deep

lingual fossa

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> This tooth has 2 cusps

So >>> The class of this tooth is premolar

3.What is the arch of thetooth??

> This tooth has 2 majorcusps which areapproximately equal in sizeand prominence>> As seen from the proximal

aspect the buccal profile isslightly inclined lingually (thewhole crown is slightly tiltedlingually)>>> The occlusal table iscentered over the root trunk>>>> As seen from theocclusal aspect the BLdimension is greater than the MD dimension


4. What is the type of this tooth??

> The presence of the MMRG (mesial marginal ridgegroove)>> The presence of canine (inter - radicular) fossawhich is deep and extends from the contact area tothe bifurcation area of the root

>>> It has 2 roots (use this feature to confirm thatthis tooth is a maxillary first premolar but don'tdepend on it as a 1007 clue coz in 207 of the casesthis tooth has 1 root instead of2)>>>> As seen from the occlusal aspect the M and Doutlines are converging lingually (they aren't parallelto each other)>>>>> As seen from the occlusal aspect the MB and DB angles aresharp

>>>>>> As seen from the occlusal aspect, the B cusp is wider MDthan the L cusp (they aren't equal in width)

Buccalas ect

Mesialas ect

Lingualas ect

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>>>>>>> As seen from the occlusal aspect the central groove is longand there are few supplemental grooves (or sometimes there is NOsupplemental grooves at all)>>>>>>>> As seen from the buccal aspect notice the overhanging of

MO and DO angles (how they are located outside the outline of theroot)

So >>> The type of this tooth is 1st premolar5. What is the side of this tooth??

> The side where you have the MMRG and the canine fossa is the Mside>> You can depend on the fact that in maxillary 1stpremolar the MSR

(mesial sloping ridge) is longer than the DSR and the MHOC is lowerthan the DHOC>>> look at the tooth from the occlusal aspect and notice that theMMR (mesial marginal ridge) is shorter than the DMR>>>> As seen from the occlusal aspect the lingual cusp is twistedmesially (the tip of the lingual cusp is mesial to the midline)>>>>> As seen from the buccal aspect the MSR (mesial slopingridge) is longer than the DSR

So >>> The side of this tooth is the right side

>>> This tooth is maxillary right permanent 1st premolar

MMR

DMR

Tip of lingualcusp which is

twisted mesially

Sharp MB angle

LongMSRShortDSR

Overhanging MO andDO angles

MHOC

DHOC

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*** Can you identify this tooth??1. The set of this tooth is permanent

2. What is the class of this tooth??

> It has 2 cusps

So >>> The class of this tooth is premolar

3. What is the arch of this tooth??

> This tooth has 1 major cusp and 1 minor cusp (the 2 cusps aren'tequal in size and prominence)>> As seen from the proximal aspect the buccal profile is markedlyconvergent lingually (the whole crown is completely tilted lingually)>>> The occlusal table is tilted lingually (it isn't centered over the roottrunk)>>>> As seen from the occlusal aspect the MD dimension is equal to

the BL dimension

So >>> The arch of this tooth is the mandibular arch


> As seen from the lingual aspect the lingual cusp is much lower thanthe buccal cusp (they aren't equal in height) and also the lingual cusp

is much smaller than the buccal cusp (they aren't equal in size)>> The presence of a groove called the ML groove (it is situated btwnthe MMR and the ML cusp ridge of the lingual cusp)>>> As seen from the occlusal aspect the MMR and the DMR areconvergent lingually (they aren't parallel to each other)>>>> As seen from the proximal aspect the occlusal plane is tiltedlingually>>>>> As seen from the lingual aspect the whole buccal profile isvisible

So >>> The type of this tooth is 1st premolar

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5. What is the side of this tooth??

> Search for the ML groove to know the M side>> As seen from the occlusal aspect the MMR is shorter than the DMR>>> As seen from the buccal aspect the MSR is shorter than the DSR>>>> As seen from the proximal aspect the MMR is higher than theDMR (this feature is only seen in this tooth coz in the other premolarsthe MMR is lower than the DMR)>>>>> The MMR is oblique (inclined lingually and cervically) while theDMR isn't as much oblique as the MMR


This tooth mandibular right permanent 1st premolar (44)

Question: premolar and a canine??t1btwn mandibularow to differentiat***1. Canine has only 1 cusp while mandibular 1stpremolar has 2 cusps2. Canine is the only cusped tooth with NO occlusal surface whilemandibular 1stpremolar has an occlusal surface2. Canine has a prominent and convex cingulum that is very cervicallylocated while the mandibular 1stpremolar doesn't have any cingulumand lingually you can observe it's lingual cusp which is very small but

more occlusally located compared with the position of the canine's

Notice how thecrown is

markedly tiltedlingually

ML groove

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cingulum (canine's cingulum is lower than the lingual cusp ofmandibular 1stpremolar)

*** Can you identify this tooth??1. The set of this tooth is permanent


> It has 3 cusps>> 1 buccal cusp + 2 lingual cusps

So >>> The class of this tooth ispremolar

3. What is the arch of this tooth??> This tooth has 1 major cusp (the B cusp) and 2 minor cusps (ML andDL cusps) (the 3 cusps aren't equal in size and prominence)>> As seen from the proximal aspect the buccal profile is markedlyconvergent lingually (the whole crown is completely tilted lingually)>>> As seen from the occlusal aspect the MD dimension is equal to theBL dimension



premolar (the only premolar withnd2It is for sure a mandibularpossibility to have 3 cusps instead of2)

You can depend also on :> None of the buccal profile is visible from the lingual aspect>> B and L cusps are almost equal in size and height (when this toothhas 2 cusps like other premolars then these 2 cusps are almost equalin every thing)>>> As seen from the occlusal aspect it has NO ML groove

>>>> As seen from the occlusal aspect the MMR and DMR are parallelto each other

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>>>>> MMR and DMR are equal in length as seen from the occlusalaspect>>>>>> As seen from the proximal aspect the occlusal plane isn't tiltedlingually (it is perpendicular on the long axis of the tooth)

>>>>>>> As seen from the occlusal aspect the main grooves form the Ylatter shape with a lingual groove that separates the ML and DL cuspsfrom each other, and the central fossa has a central pit

Question:*** How to differentiate btwn mandibular 2nd premolar (with 2 cusps)and :a) mandibular 1stpremolar

b) maxillary premolarsa) compare the 2 cusps of each premolar with each other so >> 1. if they are equal in height and size then this tooth is mandibular2

nd premolar, BUT 2. if they aren't equal in height and size then this tooth ismandibular 1stpremolar

b) Look at the tooth from the proximal aspect so >> 1. if the buccal profile is markedly tilted lingually then this tooth ismandibular 2nd premolar, BUT 2. if the buccal profile is approximately straight and it isn't tiltedlingually then this tooth is a maxillary premolar

You can use of course too many arch traits to differentiate btwn thembut the one I told you can be easily noticed and it always indicateswhether the tooth is maxillary or mandibular premolar


a) If this tooth has 3 cusps ( B + ML + DL cusps) then depend on thefact that the ML cusp is wider MD and higher (it reaches the height ofthe buccal cusp) than the DL cusp, so what you have to do is to look atthe lingual aspect of the tooth and find the higher and wider cusp ofthe 2 lingual cusps

b) If this tooth has 2 cusps, it is somehow hard to tell which side is M

and which side is D coz :

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1. As seen from the occlusal aspect the MMR and the DMR are equal inlength2. As seen from the buccal aspect the MSR and the DSR are equal inlength also3

. As seen from the proximal aspect the MMR and the DMR arehorizontal (NO one is markedly oblique than the other like inmandibular 1stpremolar)4. This tooth has NO ML groove to determine the M side

You can only depend on the fact that the MMR is lower than the DMR asseen from the proximal aspectand that the DO angle is slightly lower than the MO angle as seen fromthe buccal aspect

So >>> This tooth is mandibular right permanent 2nd premolar (4)

*** Can you identify this tooth??1. It is permanent

2. it has 2 cusps

So >>> it is a premolar

Wider andhigher ML

Smaller andlower DL cusp

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> This tooth has 2 major cusps which areapproximately equal in size and prominence>> As seen from the proximal aspect the buccalprofile is slightly inclined lingually (the wholecrown is slightly tilted lingually)>>> The occlusal table is centered over the roottrunk>>>> As seen from the occlusal aspect the BLdimension is greater than the MD dimension

archmaxillarySo >>> The arch of this tooth is the


> This tooth has NO MMR groove>> There is NO canine fossa>>> As seen from the buccal aspect the MSR and the DSR are equal inlength>>>> As seen from the occlusal aspect the MMR and the DMR are equalin length and they are parallel to each other (they show NO lingualconvergence)>>>>> As seen from the occlusal aspect there are too manysupplemental grooves and the central groove is short>>>>>> As seen from the occlusal aspect the MB and DB angles arerounded>>>>>>> As seen from the lingual aspect the L cusp has the same MDwidth of the buccal cusp

>>>>>>>> It has one root (again use this feature to confirm that thismaxillary premolar is a 2nd one but not as it is your main clue coz in 20of the cases you may find maxillary 2nd premolar with 2 roots)

premolarnd2h isSo >>> The type of this toot


It can be difficult to tell the side of this tooth coz:

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1. As seen from the occlusal aspect the MMR and the DMR are equal inlength2. As seen from the buccal aspect the MSR and the DSR are equal inlength also3

. There is NO MMR groove or canine fossa to determine the M side

But you depend on the fact that the DO angle is slightly lower than theMO angle as seen from the buccal aspect


This tooth is the maxillary right permanent 2nd premolar (1)

*** Can you identify this tooth??

1. The set of this tooth is permanent


> It has 5 cusps

So >>> The class of this tooth is molar


>This tooth has 2 roots (1 M and 1 D)>> The roots are located under the MRs

>> This tooth has 4 major cusps and 1 lesser sized cusp>>> As seen from the occlusal aspect the crown is wider MD than BL>>>> MB and DB cusps are approximately equal in size, ML and DLcusps are approximately equal in size also, but the D cusp is thesmallest



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> This tooth has 5 cusps>> This tooth has 3 buccal cusps>>> This tooth has 2 buccal grooves>>>> The crown of this tooth is very wide MD

>>>>> The roots are widely separated from each other and show NOdistal inclination>>>>>> Main grooves form " Y " pattern

So >>> The type of this tooth is 1st molar


Here you have first to orient the tooth so that it's buccal aspect is in

front of you

*** How can we know which side is buccal and which side is lingual??

>>> The B side has 3 cusps and 2 grooves while the L side has 2 cuspsand 1 groove

After you orient the tooth correctly, you have now to determine whichside is M and which side is D

*** How can we know which side is M and which side is D??

>>> Look at the tooth from it's occlusal aspect, identify the B and Lsides in the same way I told you before, in the B side there are 3 cusps,2 of them are of equal size and 1 is of lesser size, the 2 that are equal insize are the MB and DB cusps while the one of lesser size is the D cuspthat can tell you about the D side, so that you can now know the side ofthis tooth in the mouth

Buccal side

Distalside

Mesialside

Lingual side

Dcusp

MBcusp

1

23

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1 >>> lingual developmental groove that separates the ML and DLcusps from each other2 >>> distobuccal developmental groove that separates btwn D andDB cusps

3

>>> mesiobuccal developmental groove that separates btwn MBand DB cusps


>>>> This tooth is mandibular right permanent 1st molar (4)

*** Note :

* Tooth with 1 cusp = canine* Tooth with 2 cusps = premolar (it can be maxillary 3rd molar but thisrepresents very small percentage)* Tooth with 3 cusps = mandibular 2nd premolar or maxillary 3rd molar How to differentiate btwn them??>>> simply count the number of cusps buccally, so :a. 1 buccal cusp then premolarb. 2 buccal cusps then molar* Tooth with 4 cusps = maxillary molar or mandibular molar

How to differentiate btwn them??>>> simply use the arch traits like: the num of the roots (3 roots =maxillary, 2 roots = mandibular), the size of the cusps (are theyapproximately equal to each other or not), * Tooth with 5 cusps = mandibular 1stmolar


1. It is permanent


> It has 4 cusps>> It has 2 buccal cusps and 2 lingualcusps


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> This tooth has 3 roots (2 B and 1 L)

>> The roots are located under the cusps>>> This tooth has 3 major cusps (that arearranged in tricuspate triangular pattern) and 1lesser sized cusp>>>> As seen from the occlusal aspect thecrown is wider BL than MD>>>>> The 2 lingual cusps are of unequal size (ML cusp is largerthan DL cusp)>>>>>> The 2 buccal cusps aren't100 equal in size, actually the MB

cusp is slightly bigger than the DB cusp



> The roots are widely separated from each other and they show NOdistal inclination>> The size of DL cusp is large>>> The 2 B cusps are equal in height as seen from the buccalaspect>>>> The presence of cusp of carabelli (remember that thepresence of this cusp doesn't tell you 100 that this tooth is maxillary1

stmolar coz in 10 of the cases you may find maxillary 1stmolarwithout cusp of carabelli and maxillary 2nd molar with cusp ofcarabelli, so it isn't an accurate clue but it can help in confirmingthat this tooth is maxillary 1stmolar)


5. What is the side of the tooth??

Again orient the tooth so that it's buccal aspect is in front of you

*** How to know the buccal side??

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Simply the B side is the side where the 2 cusps (MB and DB cusps)are equal in height and it is the side where we have 2 roots (MB andDB roots)

Then, you have to determine which side is mesial and which side isdistal

*** How to know that??

There are 5 ways:1. look at the tooth from the occlusal aspect and look for thesmallest cusp which is the DL cusp to know the D side2. look at the tooth from the occlusal aspect and look for the largest

cusp which is the ML cusp to know the M side3. search for cusp of carabelli which is situated on the lingualaspect of the ML cusp to know the M side again4. look at the tooth from the occlusal aspect the MMR is longer thanthe DMR so that you can know the M and D sides5. look at the tooth from the buccal aspect the MB cusp is wider MDthan the DB cusp (it is the easiest way coz the tooth here is orientedcorrectly and that exclude getting confused in determining the sideof the tooth)


>>> This tooth is maxillary right permanent 1st molar (1)*** Note :

The Dr. can bring a tooth with missing root and ask you about the

reason why this root is missing, so how are you going to answer thisquestion???

1. if the apical foramina are widely opening (they are large) and theyhave very thin edge of dentine lining them from inside then this rootis still developing and it isn't complete yet

2. if the apical foramina are small and narrow and lined with thicklayer of dentine then the root was broken while the tooth was

extracted out of the mouth

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1. It is permanent


> It has 4 cusps>> it has 2 B and 2 L cusps



> It has 3 roots (2 B and 1 L)>> The roots are located over the cusps>>> The crown is wider BL than MD>>>> The 2 lingual cusps are of unequal size (MLcusp is much larger than DL cusp)>>>>> The 2 buccal cusps aren't100 equal in sizealso (MB cusp is slightly larger than DB cusp)>>>>>> This tooth has 3 major cusps (that arearranged in tricuspate triangular pattern) and 1lesser sized cusp



> The roots of this tooth are close to each other and they show distalinclination>> The size of DL cusp is small>>> The 2 B cusps aren't equal in height (DB is shorter than MB) asseen from the buccal aspect>>>> You can depend on the appearance of the oblique ridge (if it islong and prominent then this tooth is 1stmolar but if it is short andless prominent then this tooth is 2nd molar)>>>>> Many supplemental grooves

So >>> The type of this tooth is 2nd molar

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First >>> orient the maxillary tooth so that it's buccal aspect is infront of you (look for the side with 2 roots)

Second >>> determine the M and D sides (look for the smallest cuspwhich is the DL cusp to know the D side or look for the largest cuspwhich is the ML cusp to know the M side or look at the tooth from thebuccal aspect and look for the wider cusp MD which is the MB cuspor look at the tooth from the occlusal aspect and look for the longermarginal ridge which is the MMR or use cusp of carabelli if it is

present)So >>> The side of this tooth is the left side

>>> This tooth is the maxillary left permanent 2nd molar (2)


1. It is permanent


> It has 4 cusps>> It has 2 buccal and 2 lingual cusps



> This tooth has 2 roots (1 M and 1 D)>> The roots are located under the marginal ridgesnot the cusps>>> This tooth has 4 major cusps>>>> As seen from the occlusal aspect the crown iswider MD than BL

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>>>>> MB and DB cusps are approximately equal in size, ML and DLcusps are approximately equal in size also



> This tooth has 4 cusps>> This tooth has 2 buccal cusps>>> This tooth has 1 buccal groove>>>> The roots are close to each other and show distal inclination>>>>>> Main grooves form " + " pattern

>>>>>>> numerous nom of supplemental groovesSo >>> The type of this tooth is 2nd molar


The roots are always distally inclined so that the side that has NO rootunder it is the M side, you can also use the MHOC and DHOC (theMHOC is higher than the DHOC)

So >>> The side of this tooth is the left side

Distalinclination

D sideM side

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>>> This tooth is the mandibular left permanent 2nd molar (7)


1. It is permanent


* From the labial aspect :This tooth has an incisal edge that is

flattened MD


1. This tooth has long horizontal biting edge that is compressed LL2. This tooth has 3 mamelons

So >>> The class of this tooth is an incisor


> The crown is narrow MD>> MD dimension of the crown is much smaller than the IC dimension(height/width proportion is much greater than 1 it is approximatelyequals to 2)>>> The root is narrow MD and thick (bulky) LL (very important)

as seen from the incisal aspectlatThe labial surface is>>>>



We have many clues to identify the side, among them

> As seen from the incisal aspect the incisal ridge (notedge) is perpendicular on the long axis of the toothwhich is the LL line (this one is the most important clue)>> As seen from the labial aspect the MI and DI angles

are sharp (09 degrees) symmetrical>>> The crown of the tooth is bilaterally

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Flat labialsurface

Incisalridge

MIangle

>>>> The crown of the tooth is very narrow MD

So >>> The type of this tooth is central incisor5. What is the side of this tooth??

It is somehow difficult to tell the side of this tooth but you candepend on the fact that the MI angle is slightly higher than the DIangle as seen from the labial aspect or depend on the fact that theMI angle is sharper than the DI angle


>>> The tooth is the mandibular right permanent central incisor (1)


1. It is permanent


* From the labial aspect :This tooth has an incisal edge that is flattened MD


1. This tooth has long horizontal biting edge that is compressed LL

DI angle

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D sideM side

2. This tooth has 3 mamelons

So >>> The class of this tooth is an incisor


> The crown is narrow MD>> MD dimension of the crown is much smaller than the IC dimension(height / width proportion is much greater than 1 it is approximatelyequals to 2)>>> The root is narrow MD and thick LL (important)

as seen from the incisal aspectlatThe labial surface is>>>>



(not edge) isn'tidge> As seen from the incisal aspect the incisalperpendicular on the long axis of the tooth which is the LL line, ittends to be oblique (this one is the most important clue)>> As seen from the labial aspect the MI and DI angles are roundedmmetricalsy>>> The crown of the tooth is bilaterallySo >>> The type of this tooth is lateral incisor


> As I said before the incisal ridge isn't perpendicular on the LL line, ittends to incline lingually as we go distally

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>>> This tooth is the mandibular right permanent lateral incisor (2)

*** Can you identify this tooth??1. It is permanent


> It has only one conical pointed cusp>> It doesn't have an occlusal surface>>> As seen from the proximal aspect it'sroot is very thick LL>>>> It has a well developed cingulum(that's why it can't be a premolar)>>>>> It has 2 well developed depressions(Mesio-labial and Disto-labial) on the labialsurface

So >>> The class of the tooth is a canine


> The proximal outlines are inlined with the outline of the root (theyaren't overhanging)>> As seen from the proximal aspect notice that the cusp tip is

(this point is very important andL bisecting linehenlocatedcritical in the differentiation btwn max. and mand. canines)>>> IC dimension > MD dimension of the crown>>>> As seen from the lingual aspect, the cingulum isn't veryprominent, M and D marginal ridges aren't prominent also, the MLand DL fossae are very shallow and there is NO lingual pit (theentire L surface is flat)>>>>> M and D outlines are almostparallel to each other>>>>>> You can sometimes depend on the position of HOCs which

are relatively higher in mandibular than in maxillary

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4. What is the side of this tooth?? > MSR (mesial sloping ridge) is shorter than the DSR>> MI angle is higher and more rounded than the DIangle

>>> MHOC is higher than the DHOC

So >>> The side of this tooth is the right side>>> This tooth is the mandibular right permanent canine (43)

*** Notes :* The widest tooth BL is the maxillary 1st molar* The widest tooth MD is the mandibular 1st molar* The longest tooth IC is the mandibular canine* The narrowest tooth MD is the mandibular central incisor* The tooth with the longest root is the maxillary canine* The tooth with the highest M and D HOCs is the mandibular canine(it's M and D HOCs are the closest to the top of the tooth)

And now let's identify some deciduous teeth

Regarding the deciduous incisors and canines actually you have tofollow the same path you followed in identifying the permanentincisors and canines, the same class, arch and type traits

*** How can we differentiate btwn permanent and deciduous ant.teeth in general ??

You have to remember all set traits like for example :

> size (permanent larger than deciduous)>> color (permanent darker than deciduous)>>> cervical constriction (pronounced constriction in the area btwnthe crown and the root in deciduous teeth but it isn't existing in

permanent teeth)

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>>>> more bulging of labial and lingual surfaces near the cervix ofthe tooth as seen from the proximal aspect (this feature is seen indeciduous but not in permanent)

*** How to differentiate btwn permanent maxillary central incisorand deciduous maxillary central incisor ?? Use the set traits and :

> the labial surface of deciduous is flat and it doesn't have any lobesor any labial grooves or any mamelons>> MI and DI angles in deciduous are markedly overhanging theoutline of the root>>> the cingulum in deciduous is very big and more incisally located

than in permanent and has a ridge that extends toward the incisaledge>>>> the MD dimension of the crown is greater than the ICdimension in deciduous (while in permanent the IC dimension of thecrown is slightly greater than the MD dimension) this point is veryimportant

While other features are the same like for example : sharp MI angleand rounded DI angle, the MHOC is higher than the DHOC, the root

is conical,

*** How to differentiate btwn permanent canines and deciduouscanines?? Follow the set traits and :

> the labial surface of deciduous is flat and it doesn't have anylobes or any labial grooves

>> the M and D HOCs in deciduous are more cervically located(more toward the cervix of the tooth) than in permanent

** Deciduous molars **

*** Can you identify this tooth??1

. What is the set of this tooth??

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Follow the set traits and :

> notice how the roots are widely separated fromeach other (more flared outward and moredivergent and very thin)>> very little root trunk>>> the presence of cervical buccal ridge

So >>> The set of this tooth is the deciduousdentition


> It has 4 cusps



> It has 3 roots (2 B and 1 L roots)

>> The roots are located under the cusps>>> As seen from the occlusal aspect the BL dimension of the crownis greater than the MD dimension>>>> This tooth has 3 major cusps (that are arranged in tricuspatetriangular pattern) and 1 lesser sized cusp>>>>> The 2 lingual cusps are of unequal size (ML cusp is muchlarger than DL cusp)>>>>>> The 2 buccal cusps aren't100 equal in size, actually the MBcusp is slightly bigger than the DB cusp

So >>> The arch of this tooth is the maxillary arch4. What is the type of this tooth??

Follow this role :

The last deciduous tooth looks like the permanent tooth behind it

The deciduous 2nd

molars look exactly like the permanent1st

molars

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Based on this role if the deciduous molar looks like the permanent1

stmolar behind it then it's type is 2nd molar, BUT if it doesn't looklike the permanent1stmolar then it's type is 1stmolar

i.e. if you have mandibular deciduous molar and you find that itlooks exactly like the mandibular permanent1stmolar behind it thenit's type is 2nd molar, but if it doesn't then it's type is 1stmolar

*** Do you think that this maxillary deciduous molar looks exactlylike the maxillary permanent1stmolar??

Yes, so it is a typical maxillary deciduous molar and it's type is

2nd molar

*** How to differentiate btwn maxillary permanent 1st molar andmaxillary deciduous 2nd molar ?? Simply use the set traits, like:

> Size (deciduous smaller)

>> Color (deciduous lighter)>>> Amount of root trunk (very little in deciduous)>>>> Amount of root divergence and their thickness (very flaredoutward and divergent and thin in deciduous)>>>>> Cervical constriction (exists in deciduous but not inpermanent)>>>>>> The presence of buccal cervical ridge (exists in deciduous)


orient the tooth so that it's buccal aspect is in front of you

*** How to know the buccal side??

Simply the B side is the side where the 2 cusps (MB and DB cusps)are equal in height and it is the side where we have 2 roots (MB andDB roots) and it's the side with a ridge cervically (BCR) and if youview the tooth from the proximal aspect you will find that the buccal

aspect is the side where you have very prominent bulging

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Then, you have to determine which side is mesial and which side isdistal

*** How to know that??There are 5 ways:1. look at the tooth from the occlusal aspect and look for thesmallest cusp which is the DL cusp to know the D side2. look at the tooth from the occlusal aspect and look for the largestcusp which is the ML cusp to know the M side3. search for cusp of carabelli which is situated on the lingualaspect of the ML cusp to know the M side again4

. look at the tooth from the occlusal aspect the MMR is longer thanthe DMR so that you can know the M and D sides5. look at the tooth from the buccal aspect the MB cusp is wider MDthan the DB cusp (it is the easiest way coz the tooth here is orientedcorrectly and that exclude getting confused in determining the sideof the tooth)


>>> This tooth is maxillary right deciduous 2nd molar ()

*** Can you identify this tooth??1. It is deciduous


> It has 5 cusps



>This tooth has 2 roots (1 M and 1 D)

>> The roots are located under the MRs not thecusps

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>> This tooth has 4 major cusps and 1 lesser sized cusp>>> As seen from the occlusal aspect the crown is wider MD than BL>>>> MB and DB cusps are approximately equal in size, ML and DLcusps are approximately equal in size also, but the D cusp is the

smallest



This tooth looks exactly like mandibular permanent1stmolar

this tooth is mandibular deciduous 2nd molar

*** How to differentiate btwn the 2 teeth (permanent1stmolar anddeciduous 2nd molar) ??

in the same way I told you before


Here you have first to orient the tooth so that it's buccal aspect is infront of you

*** How can we know which side is buccal and which side is lingual??

>>> The B side has 3 cusps and 2 grooves while the L side has 2 cuspsand 1 groove

After you orient the tooth correctly, you have now to determine which

side is M and which side is D

*** How can we know which side is M and which side is D??

>>> Look at the tooth from it's occlusal aspect, identify the B and Lsides in the same way I told you before, in the B side there are 3 cusps,2 of them are of equal size and 1 is of lesser size, the 2 that are equal insize are the MB and DB cusps while the one of lesser size is the D cuspthat can tell you about the D side, so that you can now know the side of

this tooth in the mouth

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>>> This tooth is the mandibular right deciduous 2nd molar (5)



> it is a cusped tooth with occlusalsurface

So >>> the class of this tooth is molar3. What is the arch of this tooth??

> This tooth has 3 roots (2 B and 1 L)>> The roots are located under the cusps>>> As seen from the occlusal aspect the crown is wider BL than MD

So >>> The arch of this tooth is the maxillary arch4. What is the type of this tooth??

** Do you think that this tooth look exactly like the maxillarypermanent1stmolar???

NO, so it is an atypical maxillary deciduous molar and it's type is1

st molar

You can confirm your decision depending on many clues, like:

> this tooth has 2 major cusps (MB and ML) and 2 minor cusps (DBand DL)

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>> as seen from the buccal aspect the cervical line isn't straight(uniform), it is lower M and higher D that's why the OC dimension Mis larger than that D>>> This tooth is intermediate btwn premolar and molar



> Look at the tooth from the occlusal aspect, the M cusps are widerMD than the D cusps>> Look at the tooth from the buccal aspect, the M side is longer OC

than the D side (as we go mesially the cervical line goes cervically)So >>> The side of this tooth is the right side

>>> This tooth is the maxillary right deciduous 1st molar (4)



> cusped tooth with occlusal surface>> It has 4 cusps



> This tooth has 2 roots (1 M and 1 D)>> The roots are located under the MRs not thecusps>>> As seen from the occlusal aspect the crownis wider MD than BL

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*** Does this mandibular deciduous molar look like mandibularpermanent1stmolar??

NO, so it is the atypical mandibular molar and it's type is 1st molarHow to confirm that??

> This tooth has 4 cusps only

>>> The cervical line isn't uniform (straight), it inclines cervically aswe go mesially that's why the M side is longer OC than the D side>>>> This tooth is intermediate btwn premolar and molar



> Look at the buccal aspect of the tooth, the M side is longer OCthan the D side (the cervical line is lower M than D)>> Look at the occlusal aspect of the tooth, the largest cusp is theMB cusp that tells you about the M side


>>> This tooth is the mandibular right deciduous 1st molar (54)

*** NOTE :

If you are sure that the tooth you are looking at is a deciduous molarthen you have 4 choices :

1. if the deciduous molar looks exactly like the maxillary permanent1

stmolar then the tooth you have is maxillary deciduous 2nd molar2. if the deciduous molar looks exactly like the mandibularpermanent1stmolar then the tooth you have is mandibular

deciduous 2nd molar

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3. if the deciduous molar doesn't look like any permanent1stmolarthen it is deciduous 1stmolar (atypical molar)

*** How to differentiate btwn the 2 atypical deciduous molars??

Use the arch traits :> Number of roots (2 roots = mandibular, 3 roots = maxillary)>> Location of roots (under the MRs = mandibular, under the cusps= maxillary)>>> Dimensions of the crown as seen from the occlusal aspect(MD>BL = mandibular, BL>MD = maxillary)

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