dental morphology & anatomy

8/13/2019 Dental Morphology & Anatomy

1/22

Maxillary Central Incisor (#8 And #9)

Chronology:Eruption of deciduous: 10 monthsEruption of permanent: 7-8 yearsCalcification initiation: 3-4 months

Interproximal contacts: (And heights of contour)mesial: incisal 1/3distal: junction of incisal 1/3 and middle 1/3

All contacts are centered faciolin ually!

Heights of contour:"uccal / la#ial / facial: junction of incisal 1/3 and middle 1/3 $one source claims Cer%ical 3 rd&lin ual: cer%ical 1/3

m!rasures:Em#rasures #et'een the t'o (a) central incisors is smaller than #et'een (a) central and laterals!

"oot:*in le root+ sin le pulp canal+ root is lon er than cro'n! ,(ost li ely tooth to ha%e 1 root canal.

acial %ie': pulp cham#er 'ith 3 pulp horns+ cone-shaped 'ith #lunt ape) pointin sli htly distalin ual %ie': cone-shaped tapers distally sli htly

Cross-sectional %ie': $trian ular& mesial aspect lon er 2ulp ca%ity is flattened mesiodistally

acial $ la!ial $ !uccal:utline is trape oidala#ial surface is smooth and con%e) in the cer%ical 3 rd

anatomical cro'n is lon er than 'ide $also 'ider at incisal ed e&mesial outline is relati%ely strai ht or only sli htly con%e)distal outline is more con%e) than mesial outlineincisal outline is strai ht mamelons present on ne'ly erupted teeth $rounded terminations of 3 la#ial lo#es& mesioincisal an le is a ri ht an le+ 5istoincisal an le is more roundedCE6 cur%ed ,con%e). to'ard ape)*li ht de%elopmental depressions and rid es $distola#ial and mesiola#ial depressions&

%ingual:hese teeth are 'ider mesio-distal than #ucco-lin ual!utline is trape oidal

(esial and distal mar inal rid es are presentin ual fossa is present and is #ounded #y incisal rid e mesial and distal mar inal rid es cin ulumccasionally a lin ual pit is present

Mesial:utline is trian ular or 'ed e-shapedacial outline is cur%ed sli htly flat incisallyin ual outline is conca%ocon%e) $conca%e at incisal and con%e) at cer%ical&ooth #isects lon itudinally

Cer%ical line is conca%e to'ard root $con%e) to incisal&Mesial curvature of the CEJ is greater than the curvature on the distal aspect the CEJ on the MESIAL surface is has theGREATEST cervical curvature of any tooth in the outh!

&istal:*imilar to mesial e)cept:

Cro'n appears thic er in the incisal 1/3 $due to arch shape&CE6 cur%ature is less the mesial

Incisal:rian ular outlineooth is 'ider facially than lin ually

9ncisal ed e #isects the faciolin ual diameter ,on line 'ith root center.9ncisal surface slopes to'ard the lin ual2oint of con%e)ity is at cin ulum distal to it;s center mesial and distal contact points centered la#iolin uallymesiofacial and distofacial line an les are more prominent than ( and 5 line an les

5 is more rounded than (5e%elopmental depressions and rid es seen on la#ial surface(esial and distal mar inal rid es are present

%o!es: 4 lo#es

3 facialmesial: mesial mar inal rid e and mesial part of la#ial surfacedistal: distal mar inal rid e and distal part of the la#ial surfacela#ial: la#ial rid e $not %ery prominent&

1 lin uallin ual: cin ulum


2/22


3/22

Mandi!ular Central Incisor (#+, And #+-)

Chronology:eruption of deciduous: 8 monthseruption of permanent: D-7 yearscalcification initiation: 3-4 months

Interproximal Contacts:mesial-distal contact points are at same le%els

mesial: incisal 1/3distal: incisal 1/3

Heights of contour:#uccal: cer%ical 1/3lin ual: cer%ical 1/3

"oot:*in le $%ery narro' mesiodistally&+ cur%es distally in some cases+ $o%oid or round&>oot is lon er than cro'n len th

sually 1 pulp canal $may ha%e = - called acial and in ual pulp canals&"roader $than (5&>oot may ha%e #road de%elopmental depression alon its len th $deeper on distal than on mesial&>oot tapers apically near the middle 3 rd

*eneral:/nly sy etrical tooth in outh1 st succedaneous =th to erupt!S allest adult tooth S allest M0 di ension of any cro#n1*ets in ja' 'ith root apices facial and cro'ns lin ualFider than (5

%a!ial:utline is trape oidal!

incisal outline is strai ht $mamelons present 'hen first erupt&cro'n appro)imately t'ice as lon as 'idemesial and distal outlines are strai ht to the contact point and then taper $narro'& to cer%i)mesioincisal and distoincisal line an les are sharp $


4/22

Mandi!ular %ateral Incisor (#+. And #+/)

Chronology:eruption of deciduous: 13 monthseruption of permanent: 7-8 years calcification initiation: 3-4 months

Interproximal contact points:mesial: incisal 1/3distal: incisal 1/3 $more cer%ical&


"oot:$o%oid or round& 1 pulp canalsimilar to mand! central incisor #ut sli htly lar er depression on the distal is deeper than on the mand! central incisor

*eneral:Larger than central incisor $'ider cro'n (5 than the central incisor&

ll extra width appears to !e added to the distal aspect of the toothon a)es are positioned 'ith root apices facially and cro'ns lin ually!ar er than the mandi#ular central incisor

(ost li ely $alon 'ith mand central& of all incisors to ha%e #oth mesial and distal conca%ities!

%a!ial:incisal edge slopes do#n#ard distally distal cro'n hei ht is often shorter than the mesial cro'n hei ht(esioincisal an le is sharp $


5/22

Maxillary Canine (#/ And # )

Chronology:eruption of deciduous: 1< monthseruption of permanent: 11-1= yearscalcification initiation: 4-H months

Interproximal contact points:mesial: junction of incisal 1/3 and middle 1/3distal: middle 1/3


m!rasures: he incisal em#rasure #et'een ma) canine and lat incisor is the largest incisal e "rasure !

"oot: *in le root 'ith 1 pulp canal+ narro' (5 'ide

acial %ie': Conical+ lon and narro' mesiodistally+ ape) cur%es in apical 1/3 $mostly distally& root is con%e) on la#ial surfacein ual %ie': Iarro'er than facial+ smooth and con%e)+ de%elopmental depressions on the mesial and distal $more prominent on distal&

(esial %ie': Conical+ #road from cer%i%cal line to $1/= =/3& len th (esial de%elopmental depression present+ cusp tip la#ial to root #isect!5istal %ie': 5efinite conca%ity #et'een contact and cer%ical line Cer%ical line is flatter than mesial;s #ut it cur%es to'ards the incisal ed e+distal mar inal rid e is hea%ier and more irre ular in outline+ de%elopmental depression on root is more pronounced than mesial;s!Cross-section: o%oid+ ets more o%oid as you et closer to ape) $ha%in only one pulp horn&The a$illary canine is the tooth #ith the longest single root !

*eneral:ar er than mandi#ular canineon est tooth in arch $=7J mm&hinner (5 and thic er than the mandi#ular canine! This is "roadest &2L( single rooted tooth1he a)is is nearly %ertical!eometric form is trape oidal

%a!ial $ acial:9s a H sided fi ure $#ut is called trape oidal& from the facial!Cusp hei ht of cro'n is 1/3 of cro'n hei ht $incisal mar inB1/3 total cro'n hei ht&Cusp tip is on line 'ith the center of root $'ell-centered tooth&

he mid-facial lo#e includes the cusp tip!(esial cusp rid e is shorter and less sloped than the distal cusp rid e!(esioincisal an le is more incisal and less rounded than distoincisal an leCer%ical line cur%es apically(esial and distal outline is conca%e cer%ical to contact point*mooth 'ith no de%elopmental roo%es*hallo' mesiofacial and distofacial depressions 'here the 3 la#ial lo#es joined $( and 5 depression&>elati%ely prominent facial rid e of middle la#ial lo#e

(esial surface of cro'n is nearly parallel to lon a)is of root!he mesial to facial rid e is ,con%e). relati%e from facial to mesialhe distal to facial rid e tconca%ity in cer%ical 3 rd $'hen %ie'ed from the incisal aspect&

%ingual:Cro'n and root narro'er lin ually than la#ially

reater CE6 cur%ature on lin ual side than la#ial!5istinct mesial and distal mar inal rid es2rominent con%e) cin ulum more pronounced than the mandu#ular canine!

in ual rid e---rid e from cusp tip and #lends into incisal portion of cin ulum (esiolin ual and distolin ual fossa are present #et'een the lin ual and mar inal rid es!(esial and distal mar inal rid es are more #ul y than the mandi#ular canine!

Mesial:$trian ular or 'ed e-shaped&E)tremely 'ide faciolin ually in cer%ical 1/3 of #oth cro'n and root

a#ial outline is sli htly con%e) 'ith hei ht of contour in the cer%ical 3 rd

lin ual outline is con%e) in cin ulum area and sli htly conca%e in incisal portionCer%ical line cur%es to'ard the incisal ed e

All mesial surface profile is con%e) e)cept the part cer%ical to contact pointprominent mesioincisal an leFhen %ie'ed from the mesial aspect the cusp tip is facial to the center line!

&istal:*imilar to mesial aspect e)cept:

5e%elopmental depression on root $more pronounced&5efinite conca%ity #et'een contact point and cer%ical line+*li htly flatter cer%ical line cer%ical line e)tends more incisally on mesial side!5istal mar inal rid e is hea%ier more irre ular in outline

Incisal:la#iolin ual dimension is reater than mesiodistal dimensionmesial and distal contact points centered faciolin uallycusp tip is la#ial to center of cro'nprominent facial and lin ual rid e and distolin ual and mesiolin ual fossae

,cornerstone of the arch.%ery important from an esthetic andfunctional aspectoften last remainin tooth in the arch

uide mandi#ular mo%ementscanine eminence $#one under ums&helps support the facial musculaturelon roots sta#le: support #rid esdentures etc!thic3est 2L root


6/22

Mandi!ular Canine (#++ And #+')

Chronology:eruption of deciduous: =0 months eruption of permanent: ecall: root de%elopment is 1/= at time of eruption!

Interproximal contact points: (heights of contour)mesial: incisal 1/3distal: middle 1/3


"oot:*in le root often cur%ed to mesial $typically&1 pulp horn+ mostly 1 pulp canal sometime has =+ sometimes #ifurcated root#ecause de%elopmental depression splits at apical end+>oot cur%ature -if present- is mesial $unusual&

-more prounouced distal root conca%ity than that on mesial-root is shorter #y 1-= mm than ma)! canine

cross-section: o%oid+ ets more o%oid as you et closer to ape) - in crosssection the root is flattened in a mesiodistal directionMost li3ely anterior tooth to have 4 roots or 4 root canals5"ifurcation

*eneral:Compared to ma) canine: narro'er (5 mesial distal rid es are not as #ul y cusp hei ht is shorter!more symmetrical cro'n than ma)! canine

eneral shape 'hen %ie'ed from the facial or lin ual aspect is a penta on measurement is reater than (5 measurement

5e%elops from 4 lo#es 3 la#ial $middle #est de%eloped formin cusp& and one lin ual

%a!ial $ acial:Cusp hei ht is 1/H of cro'n hei ht as opposed to 1/3 in ma)illaCro'n is narro'ed (5 than the ma)illary canine! $9s #roader thou h&Cro'n is as lon or lon er inciso in i%ally than ma)! canine(esial cusp arm is shorter than distal cusp arm(esial outline is strai ht and in line 'ith mesial outline of the root5istal outline is con%e) and o%erhan s the root $cro'n appears #ent distally on root&

%ingual:*imilar to ma)! canine e)cept not as pronounced/de%eloped

in ual aspect is relati%ely flat smooth+

ess de%eloped $relati%e to ma)illary& cin ulum and mesial distal mar inal rid es and mesiolin ual d istolin ual fossa!Cro'n and root narro' lin ually $Fed e shape and much surface can #e seen!&

Mesial:Cer%ical 1/3 narro'er $'here is #ase of cro'n& incisal portion is thinner $(5& la#ial is less cur%ed than ma)! canine $cin etc&

in ual outline is more conca%e than ma)! canine due to less prominent cin ulumCusp tip is lin ual to line #isectin root from pro)imal %ie' $5uh&Continuous con%e) facial surface from incisal to apical end 'hen %ie'ed from the pro)imal aspect'hen %ie'ed from the a pro)imal point a line #isectin the root 'ill pass #uccal to the cusp tip

&istal:cur%ature of CE6 is less on distal than on mesialdistal de%elopmental depression is deeper than on mesial

Incisal:la#ial outline is less con%e) and facial rid e is less de%eloped than ma)illary canine $does not #ul e out as much&mesial and distal mar inal rid es are less de%eloped than ma)! canine $(ar inal rid es are lin ual structures&Cusp tip is sli htly lin ual(esial cusp arm is inclined sli htly lin ual

he cusp tip of the mandi#ular canine de%elops from the middle la#ial lo#e!

MaxillaryCro'n is lar er (ar ed con%er ence to'ard cer%ical area9ncisal mar in B 1/3 of cro'n hei ht

All anatomical features -rid es fossae etc more prominent(ar ed asymmetry 'hen %ie'ed from incisal

Mandi!ular Cro'n is smaller 9ncisal mar in B 1/H cro'n len th

in ual *urface is flatter ess prominent anatomical features

(ore symmetrical cro'n


7/22

Maxillary irst 0remolar (#- And # +)

Chronology:eruption of deciduous: $>eplaces ma) 1 st molar -eruption of permanent: 10-11 years calcification initiation: 1!H - =!H years

Interproximal contact points:mesial: middle 1/3 $9nterpro)imal contacts are offset #uccal&distal: middle 1/3 $9nterpro)imal contacts are offset #uccal& ocated just a #it more cer%ical than the mesial!

Heights of contour:#uccal: cer%ical 1/3lin ual: middle 1/3

"oot:sin le root $H0K&only premolar 'ith #ifurcated roots $H0K---= canals fused to ether& $"uccal and lin ual&

he root trun is lon a#out 1/= to =/3 total len th of root! $recall root trun is root #et'een #ifurcation and CE6road #uccolin ually narro' mesiodistallymesial de%elopmental depression#uccolin ual section: = pulp canals = pulp horns $#uccal is lar er&(5 section resem#les caninetrans%erse section: idney-shaped $cer%ical C*& #ecause of mesial conca%ity

1uccal:utline is rou hly trape oidal and is enerally con%e)!

only permanent tooth 'here mesial cusp arm is lon er and strai hter than distal cusp arm $shorter and more cur%ed&mesial conca%ity #elo' contact pointprominent #uccal rid e associated 'ith de%elopmental depressions

he mesial and distal lo#es are ,less de%eloped.

%ingual:cro'n tapers lin ually $lin ual part narro'er than #uccal and is smoothly con%e)&lin ual cusp located mesially and is 1 mm shorter more pointed than #uccal cusp so the #uccal cusp is %isi#le from this aspect!( cusp arm is shorter than 5 cusp arm so it ,2oints to'ard mesial.Io de%elopmental depressions %isi#le on the lin ual side!

Mesial:utline is trape oidal!

Cusp tip is located 'ithin confines of root surfacesmesial cusp rid e is lon er than its distal cusp rid e - only tooth 'here mesioincisal is lon er than the distoincisal"oth cusps are %isi#le and the #uccal cusp is 1 mm taller strai hter less pointed than lin ual cusp $more con%e)&mesial conca%ity is #elo' contact point $middle 1/3& allo's easy distin uish from distalmesial de%elopmental depression / conca%ity present note ma)illary second premolars don;t ha%e this

mesial mar inal rid e de%elopmental roo%e is present! $ his distin uish from ma)! second premolar&

&istal:fe' differences from mesial $a#sence of mesial conca%ity mesial de%elopmental depression mar inal rid e de%elopmental roo%e&

ess cur%ature of the cer%ical line $'hen compaed to mesial& is o#ser%ed

2cclusal:utline is he)a onal!

" dimension is reater than the (5he #uccal and lin ual cusps are each composed of 4 rid es

cro'n 'ider on the #uccal than on the lin ual(esial and distal de%elopmental pits and trian ular fossa are presentmesio#uccal cusp rid e is lon er than disto#uccal cusp rid emesiolin ual cusp rid e is shorter than distolin ual cusp rid emesial and distal mar inal rid es are present central de%elopmental roo%e is present on occlusal surface(esial mar inal de%elopmental roo%e located on occlusal surface#uccal trian ular rid e and lin ual trian ular rid e #oth end at central fossa and they are not ,an led strai ht.mesio#uccal cusp rid e mesial mar inal rid e form almost a


8/22

Maxillary 3econd 0remolar (#, And # .)

Chronology:eruption of deciduous: 5eciduous = nd ma)illary molar replaceseruption of permanent: 10-1= yearscalcification initiation: =-= L years

Interproximal contact points: (same as height of contour) mesial: middle 1/3distal: middle 1/3


"oot :*in le root is typical+ 40K ha%e = canals>oot len th is same as in ma) 12(#road " narro' (5no de%elopmental roo%e depressionM#uccolin ual section: = pulp horns of e?ual hei ht $usually 1 canal&mesiodistal section: resem#les canine $same as ma)! first premolar&trans%erse section: o%al shaped ci ar shaped pulp ca%ity

*eneral:>esem#les ma)illary first premolar---more rounded less an ular more %ariation sin le-rooted

1uccal:similar to ma)! first premolar

ess prominent than 12(: (" and 5" line an les #uccal cusp rid e #uccal de%elopmental depressions less prominent than 12((" cusp rid e is shorter than 5" cusp rid e"uccal cusp not as lon as in 12( #uccal cusp rid e is not as o#%ious!

he #uccal de%elopmental roo%es are not as 'ell de%eloped as in the 12(!

%ingual:in ual cusp is lon er than that of ma) 12( so as a result less of #uccal cusp is %isi#le 'hen %ie'ed from the lin ual $compared to the 1 st

premolar&

Mesial:"uccal and lin ual cusps are appro)imately e?ual in si e#uccal and lin ual cusps are shorter than ma)illary first premolar #uccal and lin ual cusp tips are further apartno mesial mar inal rid e de%elopmental roo%e no mesial de%elopmental depression this is ma) 12( stuff!

&istal:

similar to mesial! CE6 is more strai ht!

2cclusal:*hape is rounded or o%al(" and 5" line an les are more rounded

ess lin ual con%er encehe central roo%e is shorter $mesial and distal mar inal rid es are 'ider&

@as more supplemental roo%es than the 1 st ma)illary premolar $'rin led appearance&


9/22

Mandi!ular irst 0remolar (#+ And #+8)

Chronology:eruption of deciduous: I 5EC95 *eruption of permanent: 10-1= years calcification initiation: 1!H =!H years

Interproximal contact points:mesial: middle 1/3distal: middle 1/3 $#roader than mesial&

Heights of contour:#uccal: junction of middle 1/3 and cer%ical 1/3lin ual: middle 1/3

"oot:*in le rootrounded cur%es distally roo%ed lon itudinally $mesial roo%e more mar ed&may #e #ifurcated #ut rare

1uccal:*hape is trape oidalprominent #uccal rid e'ell-de%eloped middle #uccal lo#emesial cusp arm is shorter than distal cusp armmesial outline is strai ht/sli htly conca%edistal outline is sli htly conca%ecer%i) is much narro'er mesiodistally than the cro'n 'idth at the contact points

%ingual:lin ual cusp is small and may resem#le canine cin ulumcro'n and root taper from #uccal to lin ualocclusal surface slopes lin ually in a cer%ical directionmesial and distal outlines are conca%e from cer%ical mar in-contact areasonly premolar that has a mesiolin ual de%elopmental roo%e $demarcates lin ual lo#e from mesiofacial lo#e---separates mesial mar inal rid efrom lin ual cusp&root tapers to pointed ape)more de%elopmental depressions or roo%es mesially on root

Mesial:*hape is rhom#oidal!#uccal outline is %ery cur%ed/con%e)lin ual outline is much less con%e)#uccal cusp tip is centered o%er the midline of the rootlin ual cusp tip on a line 'ith lin ual #order of root

distance from CE6 to lin ual cusp tip is =/3 distance from CE6 to #uccal cusp tip

&istal:only tooth in 'hich the mesial mar inal rid e is at a lo'er le%el than the distal mar inal rid e $slopes cer%ically from #uccal to lin ual notperpendicular li e most other teeth&distal mar inal rid e almost at ri ht an les to the lon a)is of toothroot shallo' de%elopmental depression #ut not roo%e

2cclusal:mesio- and disto- #uccal line an les prominent yet roundedmesial and distal contacts centered la#iolin ually#uccal and lin ual trian ular rid es joined to ether to form a sin le rid e called the trans%erse rid e Nseparates mesial occlusal fossa fromdistal occlusal fossaO $#uccal trian ular rid e lar er than lin ual trian ular rid e&distal occlusal fossa is lar er than mesial occlusal fossacusps separated #y a central roo%e as in ma)illary premolars


10/22

Mandi!ular 3econd 0remolar (#+ And #+9)

Chronology:eruption of deciduous: I 5EC95 *eruption of permanent: 10-13 years $usually erupt after the ma)illary canine #ut may occur alon 'ith it&calcification initiation: 1!H =!H years

Interproximal contact points:mesial: middle 1/3distal: middle 1/3

Heights of contour:#uccal: junction of middle 1/3 and cer%ical 1/3lin ual: middle 1/3

"oot :*in le root that cur%es distallyroot ape) is more #lunt and lon er than mandi#ular first premolar

*eneral:= types of (andi#ular = nd premolar e)ist:

)3 cusp type N1 facial = lin ualO $H lo#es& --- most common#uccal cusp > mesiolin ual cusp > distolin ual cusp

+)= cusp type $4 lo#es&

1uccal:resem#les mandi#ular first premolar #uccal cusp is shorter and less pointed than that of mand! first premolar

%ingual:differs from cro'n of mand! first premolar lin ual lo#es are #etterde%eloped3 cusp type---= lin ual cusps $mesiolin ual and distolin ual cusps& areseparated #y lin ual roo%e

Mesial:*hape is rhom#oidaldifferences from mand! first premolar

-cro'n and root are 'ider #uccolin ually than mand! first premolar -#uccal cusp tip is not as lin ually placed-lin ual and #uccal cusps are more e?ual in si e-mesial mar inal rid e is at ri ht an les to the lon a)is of the tooth-no mesiolin ual de%elopmental roo%e

can only see = cusps from this %ie'

&istal:*imilar to mesial e)cept that distal mar inal rid e is at a lo'er le%el can see all 3 cusps

2cclusal:

. cusp type $most common formin a P-shape more common&= lin ual cusps and 1 #uccalde%elopmental roo%es separate cusps to form a P-shape on occlusal $mesial distal lin ual&central pit---'here the 3 roo%es meetmesial trian ular fossa and distal trian ular fossalar e mesiolin ual roo%e that separates the mesial mar inal rid e from the lin ual cusp!

+ cusp type $@-shaped and -shaped--- -shaped is least common&outline is roundedlin ual con%er ence of mesial and distal mar inal rid es lin ual cusp 'ell de%elopedmesiolin ual and distolin ual line an les are rounded

central de%elopmental roo%e mesial and distal de%elopmental fossamay or may not ha%e mesial and distal de%elopmental pits


11/22


12/22

*eneral Characteristics of MA6&I1 %A" 0" M2%A"3

succedaneous teeth $replace deciduous molars&misleadin to refer to them as ,#icuspids.mandi#ular first premolar de%elops from 4 lo#es $3 facial and 1 lin ual& = cuspsmandi#ular second molar de%elops from 4 or H lo#es $3 facial and 1-= lin ual& =-3 cuspsmandi#ular second premolar is #i er than mandi#ular first premolar lin ual cusp$s& are less prominent than the #uccal cuspcro'ns are mar ed 'ith lin ual inclinationmandi#ular first premolar has one roothei ht of contour of lin ual profile is closer to cusp tipmandi#ular first premolar: mesiolin ual de%elopmental roo%e

= cusp premolar 3 cusp premolar 4 lo#es H lo#es

1&lin ual 1&mesiolin ual=&mesiofacial =&distofacial3&middlefacial 3&mesiofacial4&distofacial 4&middlefacial

H&distofacial

*eneral Characteristics of MA4I%%A"5 M2%A"3

3 roots----= #uccal 1 lin ual $the lar est&4 cusps----3 major cusps 1 smaller cusp $1 st molar has H th cusp&( cusp is the lar est( (" and 5" cusps form a trian le----tri on or primary cusp trian le5" cusp is the smallest and decreases in si e from the first to the third molar cro'ns are #roader " than (55" cusp is connected to ( cusp #y an o#li?ue rid ecro'n relati%ely short occluso-cer%ically

*eneral Characteristics of MA6&I1 %A" M2%A"3

lar est mandi#ular teeth%ariations in num#ers of cusps

- enerally H cusps in 1 st 4 cusps in = nd

teeth #roader mesiodistally than #uccolin ually

1st

molar has H lo#es and H cusps=nd molar has 4 lo#es and 4 cusps

7 7H 7I& 1I73

All teeth are trape oidal in shape from the #uccal aspect

9n most teeth the distal contact point is positioned more cer%ically than mesial contact point $e%en if it is located in the same 1/3 of tooth&

All teeth are #road on facial and narro' on lin ual

All teeth ha%e a reater #uccolin ual dimension than mesiodistal dimension 4C 07 : mandi#ular molarsma)illary incisors $central and lateral&

All teeth are shorter as you o anterior to posterior #ecause distal mar inal rid e is usually shorter than mesial mar inal rid e 4C 07: mandi#ular firstpremolar

(esial mar inal rid e is usually perpendicular for most teeth 4C 07: mandi#ular first premolar $slopes cer%ically from #uccal to lin ual&

A ma)illary molars $permanent 1-3 and primary 1-=& ha%e o#li?ue rid es


13/22

&eciduous &entition Chronology:

irst si n of tooth de%elopment: D-7 'ee s $in utero&Calcification #e ins: 13-1D 'ee s $in utero&Calcification of all teeth ha%e #e un: 18-=0 'ee s2rimary dentition completed: =!H - 3 yearsCompletion of root de%elopment for primary dentition: 1!H yr after eruption

mandi#ular central incisorQQQQQQ!8 monthsma)illary central incisorQQQQQQQ10 months

ma)illary lateral incisorQQQQQQQ!11 monthsmandi#ular lateral incisorQQQQQQ13 months

ma)illary first molarQQQQQQQQQ!1D months "generally !efore mandi!ular first molar)mandi#ular first molarQQQQQQQQ1D months

(a)illary canineQQQQQQQQQQQQ!!1< monthsmandi#ular canineQQQQQQQQQQQ!=0 months

mandi#ular second molarQQQQQQ!!=7 monthsma)illary second molarQQQQQQQQ=< months

0ermanent &entition Chronology:

Calcification initiation:$1st part to calcify is the cro'n&

Incisors - 3-4 monthse)cept: ma)illary lateral incisor: 10-1= months

Canines: 4-H months0remolars : 1!H =!H years

ma)! 1 st : 1 G - 1 R years ma)! = nd : =- = L yearsmand! 1 st: 1 R - = years mand! = nd : = L - = G years

st molars : "9> @+nd molars : =-3 years

ma)!: = G - 3 years mand!: = G - 3 years. rd molars : 7-10 years

ma)!: 7-< years mand!: 8 10 years

Calcification complete: 1/= time of eruptionOJ1 year

"oot de;elopment complete: =-3 years after eruption

mandi#ular first molarQQQQ!!D yearsma)illary first molarQQQQ!QQD years

mandi#ular central incisorQQ!!D-7 yearsma)illary central incisorQQQ!!7-8 years

mandi#ular lateral incisorQQ!!7-8 yearsma)illary lateral incisorQQQQ8-< years

mandi#ular canineQQQQQQQQ


14/22

Maxillary irst Molar (#. And # ,)

Chronology:eruption of deciduous: 1D months $ enerally #efore the mandi#ular first molar&eruption of permanent: D years $ enerally after the mandi#ular first molar&calcification initiation: "9> @

Interproximal contact points: mesial: middle 1/3 $offset to #uccal&distal: middle 1/3 $offset to #uccal&


"oot:3 roots: = #uccal and 1 lin ual $(esio#uccal 5isto#uccal in ual&>oots are splayed $'ider than cro'n 'idth&

$13 mm& S (" $1= mm& S 5" $1=mm&in ualB1 canal

("B1 $or = canals H0K of time&5"B1 canal

#uccal %ie': 3 roots %isi#le---(": strai ht cur%es distally at ape)+ 5": smallest+ : lon estroot trun is 1/3 len th of root+ point of #ifurcation is 4 mm apical CE6+ roots t'ice as lon as cro'n $'hole root is 1= mm&

lin ual %ie': 3 roots %isi#le---lin ual root is lon est and in line 'ith lin ual roo%e+ shallo' depression on lin ual aspect from terminus oflin ual roo%e to the center of the lin ual roo%e to the center of the lin ual root until the middle 1/3 of root

e%els of #ifurcations:mesial : 3 mm apical to CE6#uccal: 4 mm apical to CE6distal: H mm apical to CE6

1uccal:*hape is rou hly trape oidal!parts of the 4 major cusps are %isi#lemesial profile: con%e) and flat+ distal profile: con%e) spheroidal $o#tuse perspecti%e&(" cusp S 5" cusp5" cusp is more pointed that (" cusp(" and 5" cusp are separated #y #uccal de%elopmental roo%ecan #e difficult to remo%e calculus and restore tooth #ecause of conca%ity at the cer%ical area on the distal surface of the 5" cusp

%ingual:= %isi#le cusps $( and 5 &( and 5 cusps separated #y lin ual roo%e $ends in the middle of the lin ual surface&( cusp B 3/H mesiodistal 'idth of tooth

-( #roader and the lon est and the lar est-( cusp has Cusp of Cara#elli

-5 is spheroidalMesial:*hape is trape oidal!tooth con%er es occlusally $ma)imum " 'idth is at cer%i)&only (" and ( cusp are %isi#lecer%ically to contact area shallo' conca%ity 'hich e)tends to the mesial area of the root trunmesio#uccal and lin ual roots %isi#le

-(" root is #road " hides 5" root-lin ual root is narro' " $#anana-shaped& H0K cur%es #uccally-le%el of #ifurcation B 3 mm apical to CE6

2cclusal:*hape is rhom#oidal!acute an les B (" and 5o#tuse an les B ( and 5"cro'n 'ider #uccolin ually than mesiodistallymesial aspect S distalonly tooth 'hich #roadens to'ard the lin ual( cusp lar est S (" S 5" S 5 S fifth cusp of Cusp of Cara#elli( (" and 5" cusps are from the primary molar trian le $tri on&o#li?ue rid e B distolin ual cusp rid e of the ( cusp and the trian ular rid e of the 5" cusp

-o#li?ue rid e is the same le%el in center as the mar inal rid es= major fossae

-central fossa lies in the center of the tri on mesial to the o#li?ue rid e rou hly trian ular -distal fossa distal to o#li?ue rid e rou hly linear

= minor fossa-mesial trian ular fossa-distal trian ular fossa

central pit: central de%elopmental roo%e #uccal roo%e trans%erse roo%e of the o#li?ue rid edistal pit: distal o#li?ue roo%e lin ual roo%e

&istal:cro'n constricts to'ard distal $#uccalaspect is %isi#le from distal&3 roots %isi#le#ifurcation is a#out H mm apical to CE6distal root smoothly rounded5" conca%ity around the cer%ical area


15/22

Maxillary 3econd Molar (#+ And # -)

Chronology:eruption of deciduous: =< monthseruption of permanent: 1=-13 yearscalcification initiation: = G -3 years

Interproximal contact points:mesial: middle 1/3 $offset to #uccal&distal: middle 1/3 $offset to #uccal&


*eneral:cro'n is smaller shorter more rhom#oidal than ma)illary 1 st molar = occlusal types:

1& rhom#oidal $resem#les 1 st molar&---most common=& heart-shaped $resem#les 3 rd molar&---'hen 5 is a#sent

roots are as lon or lon er distally inclined5 cusp is smaller 5" cusp is less de%elopedIo cusp of Cara#elli

1uccal:cro'n is shorter and narro'er mesiodistally5" cusp is smaller roots are more parallel and inclined to distal(" root ape) is in line 'ith #uccal roo%e

%ingual:5 cusp is much smaller lin ual root is narro'er mesiodistallylin ual root distal inclination

-ape) lines up 'ith 5 cusp tipno Cusp of Cara#elli

Mesial:similar to ma)! 1 st molar #ut shorter cro'n hei htsame " 'idth as the ma)! 1 st

roots do not di%er e as much----confined 'ithin cro'n 'idth

&istal:cro'n con%er es to'ards the distal

5" and 5 cusps are smaller and much of the occlusal surface and ( cusp %isi#leall 3 roots %isi#le

2cclusal:*hape is more rhom#oidal!(" ( cusps are 'ell-de%eloped" dimension similar to 1 st (5 smaller 5" and 5 cusps less de%eloped ---tooth constricts to'ards the distalcro'n con%er es to'ards the lin ualmore %aria#le pit and roo%e anatomysome ha%e no 5 cusp---heart-shaped

Maxillary 7hird Molar (# And # /)

Chronology:

eruption of deciduous: I 5EC95 *eruption of permanent: 17-=1 years $ enerally after ma)illary 3 rd molar&calcification initiation: 7-< years

*eneral:most %aria#le tooth anatomy in dentitionsmaller (5 and cer%ico-occlusally less de%eloped than the ma)! = nd molar may resem#le 1 st or = nd molar 5 cusp is poorly de%eloped or a#sent1 lin ual cusp usuallyheart-shaped occlusal usuallyroots are shorter and usually fused $3&


16/22

Mandi!ular irst Molar (# 9 And #. )Chronology:

eruption of deciduous: 1D months $ enerally after the ma)illary first molar&eruption of permanent: D years $ enerally #efore the ma)illary first molar&calcification initiation: "9> @

Interproximal contact points:mesial: middle 1/3distal: middle 1/3


"oots: = roots---mesial root cur%es distally and the distal root points in a distal direction $roots are #road la#iolin uallyuccal %ie': = roots $mesial and distal&

-#ifurcation is 3 mm apical to CE6-roots are 'ider (5 on #uccal than on lin ual-de%elopmental depressions on mesial and distal aspects of each root and #uccally on root trun from CE6 to furcation $hour- lassshape&

1uccal:*hape is trape oidal!H cusps %isi#le $lin ual cusps is taller than the #uccal cusps&(" cusp S 5" cusp S distal cusp= roo%es

-(" de%elopmental roo%e shorter and terminates in middle 1/3 of tooth mesial to the #ifurcation-5" de%elopmental roo%e terminates in cer%ical 1/3 near 5" line an le

cer%ical line cur%es apicallymesial outline is con%e) and conca%e+ distal outline is con%e) and strai htconca%ity is small at the CE6

%ingual:3 cusps %isi#le $( 5 and distal&( S 5 $'ider and taller&lin ual de%elopmental roo%e separatin ( and 5 cuspsmesial and distal aspects of the cro'n %isi#le due to lin ual con%er ence= roots: lon er on lin ual than #uccal $J 1mm& #ecause CE6 is more coronalCE6 is 4mm from #ifurcation $#ifurcation is in l ine 'ith lin ual roo%e&root narro's faciolin ually

Mesial:*hape is rhom#oid!= cusps $(5 and ( & and 1 root $mesial& are %isi#ledistal portion of tooth is I %isi#le

-mesial of tooth is #roader " than distal-mesial cusps are taller/hi her than distal cusps

tooth con%er es distolin uallycro'n has a lin ual tilt in relation to its root a)is(" cusp in line 'ith #uccal 1/3 mesial root

lin ual cusp tip in line 'ith lin ual 1/3 of the root#lunt root ape) that lies under (" cusp+ sli ht mesial de%elopmental depression on rootcer%ical line cur%es occlusally----1 mm+ cer%ical line is hi her lin ually than #uccally

&istal:more tooth %isi#le---can see all cusps $tooth is shorter and narro'er to distal&distal mar inal rid e is shorter and dips cer%ically5" de%elopmental roo%e ends on distal surface at disto#uccal line an le---can see 5" roo%edistal cusp ma es up the distal contact

2cclusal:*hape is he)a onal or D sided!(5 'idth of cro'n is reater than "cro'n is 'ider " on mesial aspect $tapers distally&cro'n is 'ider (5 on #uccal aspect $tapers lin ually&---#ecause the 3 rd cusp is on #uccal(" S ( S or B 5 S 5" S 5most #uccal surface %isi#letooth narro's mesiodistally1 major fossa B central fossa----circular centrally placed #et'een cusp rid es

#oundaries of central fossa-distal slope of (" cusp-mesial and distal slopes of 5" cusp-mesial slope of distal cusp-distal slope of ( cusp-mesial slope of 5 cusp

= minor fossae B mesial trian ular fossa and distal trian ular fossa $#ase of trian le at mar inal rid e&de%elopmental roo%es

-central de%elopmental roo%e $mesial mar inal rid e distal mar inal rid e&-mesio#uccal de%elopmental roo%e $(" from 5" cusp&-disto#uccal de%elopmental roo%e $5" cusp from distal cusp&-lin ual de%elopmental roo%e

can ha%e central pit at #ase of fossa-mesial and distal pit


17/22

Mandi!ular 3econd Molar (# 8 And #. )

Chronology:eruption of deciduous: =7 monthseruption of permanent: 11-13 yearscalcification initiation: = G -3 years

Interproximal contact points: $more cer%ical than mand! 1 st molars&mesial: middle 1/3distal: middle 1/3

Heights of contour:#uccal: cer%ical 1/3 $not as pronounced&lin ual: middle 1/3

*eneral:smaller than mandi#ular 1 st molar 4 cusps $(" ( 5" 5 &----no distal or H th cusp= roots $mesial and distal root&---roots are not as #road #uccolin ually $narro'er&

roots are not as 'idely separated as in the 1 st mandi#ular molar

1uccalal:*hape is trape oidal!cro'n is shorter and narro'er than the first molar 4 cusps %isi#le $(" 5" ( and 5 &

-lin ual cusps are taller and more pointed than #uccal cusps#uccal de%elopmental roo%e separates = #uccal cuspscer%ical line points to'ard #ifurcationroots closer more parallel inclined distallyroot trun is shorter

%ingual: *hape is trape oidal!cro'n con%er es to lin ual #ut less than the 1 st molar CE6 hi her on lin ual than on #uccalcan only see = cusps $lin ual cusps&

Mesial:similar to 1 st molar e)cept:

#uccal cur%ature and #uccal cer%ical rid e are less pronouncedcer%ical line is less cur%edmesial root more pointed ape)#uccal hei ht of contour $cer%ical 1/3& is not as pronounced

&istal: no distal cuspcan see more of occlusal surface

2cclusal:*hape is rectan ular!no distal cusp---rectan ular 5" cusp is more prominentall 4 cusps relati%ely e?ual in si ecross-shaped de%elopmental roo%es $central lin ual and #uccal roo%es&

-central roo%e runs mesiodistallymore supplemental roo%es---'rin ly appearance


18/22

Mandi!ular 7hird Molar (# ' And #.+)

Chronology:eruption of deciduous: I 5EC95 *eruption of permanent: 17-=1 years $ enerally #efore ma)illary 3 rd molar&calcification initiation: 8-10 years

*eneral:ma)illary and mandi#ular 3 rd molars are most %aria#le teeth in mouth-----mandi#ular 3 rd molar is the second most %aria#le tooth in mouthusually similar to other mandi#ular molarsanomalies:

-most of mandi#ular 3 rd cro'ns are o%ersi ed-most ma)illary 3 rd molars are undersi ed

mandi#ular 3 rd molars are commonly impactedcro'n tends to #e lar er and ha%e more cusps

-4 cusps---cross-shaped-H cusps---P-shaped-D cusps

1uccal:= cusps and = roots $shorter&

%ingual:*imilar to #uccal

Mesial:root shorter and more tapered

&istal:similar to mesial #ut narro'er

2cclusal:more rounded


19/22

&eciduous (0rimary) 7eeth

=0 in num#er erupt from 8-30 months and complete at =!H years

pattern of eruption:Central incisors: $mand ma)&

ateral incisors: $ma) mand&irst molars: $ma) mand&

Canines: $ma) mand&*econd molars: $mand ma)&

pattern of e)foliation:9ncisors

irst molarsCanines*econd molars - hi hest caries ris #ecause of anatomy of occlusal are present the lon est

eeth e)foliate #et'een D-1= years>esorption #e ins 1-= years after root formation is complete and initiates at ape)!

Anterior permanent teeth de%elop lin ual to the primary teeth $lin ual is resor#ed #efore the facial&2osterior permanent teeth de%elop #et'een roots of primary teeth1= permanent teeth erupt distal to the primary second molars! hese are referred to as accessional or nonsuccedaneous teeth!

Importance of primary teeth:1! (echanical preparation of food=! (aintenance of space:

Early loss may cause se%ere cro'din2rimary teeth maintain space for permanent teeth

3! *peech4! AppearanceH! *timulate ro'th of mandi#le and ma)illary

0rimate space: A space that e)ists mesial to the primary ma)illary canine and distal to the primary mandi#ular canine in some deciduous dentitions+named after similarity found in primate dentition%ee


20/22

0rimary Maxillary Central Incisor ( And )

*eneral:de%elops from 4 lo#es $3 facial and 1 lin ual&root: cone-shaped lon and slender dimensions:

-(5 S "-(5 S 9-cro'n tapers from facial to lin ual-root tapers from facial to lin ual

%a!ial:Fider (5 than tall $ &

(5 diameter $D!H mm& of cro'n is reater than the inciso in i%al len th $D!0 mm&opposite to the permanent central incisorsonly incisor in either dentition 'ith this feature

root len th is proportionately reater than permanent central incisor root/cro'n for primary central B 10/Droot/cro'n for permanent central B 10/13

%ingual:anatomy is similar to permanent central incisor

mesial and distal mar inal rid es %ery 'ell de%elopedcin ulum is %ery pronounced $%ery tall&cin ulum e)tends up to'ard incisal ed e partially di%idin the lin ual fossa into ( and 5 fossaemore rounded distoincisal an le

Mesial and &istal:e)tremely 'ell-de%eloped lin ual and facial cer%ical rid es in the cer%ical third of the toothmuch more #ul y tooth than the permanent central incisor CE6 cur%ature reater on mesial than on distal

Incisal:mesiodistal diameter is reater than faciolin ual diameter facial of tooth is #roader than lin ual

0rimary Maxillary %ateral Incisor (& And *)

*imilar to primary central incisor #ut smaller ETCE2 :inciso in i%al $9 & len th is reater than mesiodistal $(5&distoincisal an le is more rounded than the central incisor o%erall the cro'n is smaller cin ulum doesn;t e)tend to incisal ed eprominent cer%ical rid es on mesial and distal

0rimary Maxillary Canine (C And H)

acial:resem#les permanent canine---sin le 'ell de%eloped sharp cusp%ery pronounced cer%ical constrictionmesial slope of the cusp is lon er than the distal slope of the cuspcusp hei ht is reater percenta e of cro'n hei ht $H0K& than in the permanent toothmesial and distal contact points are at the same le%elroot loo s t'ice as lon as len th of cro'n

%ingual:same anatomy as ma)illary permanent canine

mesial and distal mar inal rid eslin ual rid e---tu#ercle at the cusp tip( and 5 fossaecin ulum

root is %ery lon ---almost t'ice as lon as cro'n+ root tapers from facial to lin ual

Mesial and &istal:%ery 'ide in cer%ical areaCE6 cur%ature is reater on mesial

Incisal:diamond shapedcusp tip is distal to midline


21/22

0rimary Mandi!ular Central Incisor (2 And 0)

*mallest tooth in the mouthoo s li e permanent mandi#ular incisors

>oot is lon and slender >oot is t'ice the len th of cro'n

2ronounced cer%ical #ul es on facial and lin ual aspects

0rimary Mandi!ular %ateral Incisor (6 And =)

Cro'n is similar to the central incisor #ut is sli htly lon er in ual anatomy may #e more pronounced

(ore prominent mar inal rid es5eeper lin ual fossa

59 an le is sli htly rounded(9 an le is reater than


22/22

0rimary Maxillary 3econd Molar (A And >)

*eneral:>esem#les permanent ma)illary first molar >hom#oidal outline( (" 5" 5 cusps $(" S 5"&@as accessory cusp 7u!ercle $ Cusp of Cara!ellio#li?ue rid esame fossae and roo%es as permanent ma)illary first molar 3 roots----(" 5" and

Comparison dips apically on mesialmesial contour is strai ht or flatdistal is mar edly con%e)= distinct #uccal cusps not de%elopmental roo%e #et'een cuspse)tremely prominent (" con%e)ity

prominent (" line an le%ery prominent (" cer%ical #ul e/rid e

%ingual:( and 5 cusps( cusp is centered in the tooth ----in line 'ith mesial root $%ery pointed&mesial mar inal rid e is %ery 'ell de%eloped and loo s almost li e another cusp

Mesial and &istal:e)treme con%e)ity #uccally on the (" cuspflattened #uccal surface especially 'hen %ie'ed from the mesialrectan ular appearance of the mesial rootdistal root tapers at the ape)

2cclusal:*hape is rhom#oid!4 cusps $( (" 5 5"&( cusp is lar est and centered in the lin ual aspectmesial and distal trian ular fossae joined #y central de%elopmental roo%elin ual and #uccal de%elopmental roo%esmesial pit and central pit

0rimary Mandi!ular 3econd Molar (? And 7)

Closely resem#les the permanent mandi#ular first molar

H cusps---3 #uccal and = lin ual3 #uccal cusps are more e?ual in si edistal cusp is relati%ely lar er compared to the permanent mandi#ular first molar

= lin ual cusps e?ual in si e

= roots---mesial and distalslender and splayed

Comparison 'ith 2ermanent (andi#ular irst (olar "ifurcation of root close to CE6>oots flared3 #uccal cusps e?ual in si e: distal 5" and ("= lin ual cusps: ( and 5Cer%ical constricition

dental morphology & anatomy

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