Developmental Disturbances of Teeth

DR IMAN METWALY

IntroductionIntroduction

��Development of human body begins with a of Development of human body begins with a of series series cell division , , multiplicationmultiplication & & differentiation differentiation into various structuresinto various structures

��AA failurefailure or or disturbancedisturbance that occurs during that occurs during ��AA failurefailure or or disturbancedisturbance that occurs during that occurs during these processes may results in a these processes may results in a lacklack ,,excessexcess or or deformitydeformity of a body partof a body part

��These are called These are called developmentaldevelopmental disorderdisorder , , developmental developmental anomaliesanomalies , , abnormalitiesabnormalities or or disturbancesdisturbances

Developmental disturbances of teethDevelopmental disturbances of teeth

��Abnormalities of morphodifferentiationAbnormalities of morphodifferentiation : :

abnormalities in the differentiation of dental abnormalities in the differentiation of dental

lamina & tooth germs causes abnormalities in lamina & tooth germs causes abnormalities in

thethe numbernumber , , sizesize ,and ,and formform of teethof teeththethe numbernumber , , sizesize ,and ,and formform of teethof teeth

��Abnormalities of histodifferentiationAbnormalities of histodifferentiation : :

abnormalities in the formation of the dental abnormalities in the formation of the dental

hard structure resulting in disturbances hard structure resulting in disturbances in tooth in tooth

structurestructure

��Disturbance may be :Disturbance may be :

Developmental disturbance of teethDevelopmental disturbance of teeth

Hereditary { genetics }Hereditary { genetics }

Acquired{ environmental }

11--Disturbances in number of teethDisturbances in number of teeth

1.1. Total Total anodontiaanodontia :total failure of development of a :total failure of development of a

complete dentition {extremelycomplete dentition {extremely rarerare} }

2.2. Partial Partial anodontiaanodontia {{hypodontiahypodontia} :failure of } :failure of

development of one or more teeth {relatively development of one or more teeth {relatively

common common and often hereditary} the teeth most and often hereditary} the teeth most common common and often hereditary} the teeth most and often hereditary} the teeth most

frequently missing are frequently missing are third molarsthird molars , permanent , permanent

maxillary lateral incisorsmaxillary lateral incisors , & , & 22ndnd premolarspremolars

3.3. HypodontiaHypodontia or or anodontiaanodontia associated with associated with systemic defectssystemic defects

11) Hereditary ) Hereditary hypohidrotichypohidrotic ectodermalectodermal dysplasia dysplasia

22) Down syndrome :missing third molars) Down syndrome :missing third molars

��Characterized by congenital Characterized by congenital losslossof of ectodermalectodermal structuresstructures

��HypodontiaHypodontia

Hereditary Hereditary hypohypohidrotic ectodermal dysplasiahidrotic ectodermal dysplasia


��Inability to sweat due to absence Inability to sweat due to absence

of of sweat glandssweat glands {{anhidrosisanhidrosis}}

��Smooth, shiny and dry Smooth, shiny and dry skinskin

��ScantyScanty hair hair {{hypotrichosishypotrichosis}}

��Defective finger Defective finger nailsnails

Sex linked recessive trait

Disturbances in number of teethDisturbances in number of teeth

��Missing maxillary lateral incisorsMissing maxillary lateral incisors

�� Partial Partial anodontiaanodontia , missing bilateral , missing bilateral maxillary maxillary

secondsecond

?premolar

?


bicuspidbicuspidCongenitally missing Congenitally missing

Anodontia of a permanent 2nd premolar with

ankylosis of an erupted deciduous molar

�� Additional teeth {relatively common}Additional teeth {relatively common}

�� These are the result of These are the result of excessive excessive growth growth

of the of the dental laminadental lamina {unknown cause}{unknown cause}

��Supplemental teethSupplemental teeth :: extra teeth that morphologically extra teeth that morphologically

resembleresemble normal teeth {normal teeth {maxillary lateral incisormaxillary lateral incisor, ,


HyperdontiaHyperdontia

resembleresemble normal teeth {normal teeth {maxillary lateral incisormaxillary lateral incisor, ,

premolarspremolars & & 44thth molarmolar}}

��Supernumerary teethSupernumerary teeth : extra teeth that : extra teeth that

morphologically morphologically differdiffer from normal teeth {from normal teeth {conicalconical or or

peg peg shaped}shaped}��Several Several termsterms have been used to describe have been used to describe

supernumerary teeth depending on their supernumerary teeth depending on their

locationlocation

MesiodensMesiodens : a supernumerary : a supernumerary tooth in the tooth in the midlinemidline between between the maxillary central incisors the maxillary central incisors

DistomolarsDistomolars : : an accessory an accessory fourth molarfourth molar


fourth molarfourth molar

ParamolarParamolar ::a posterior tooth a posterior tooth situated situated linguallylinguallyor or buccallybuccally to a molarto a molar


MesiodensMesiodens

��SupplementalSupplemental

��lateral incisorslateral incisors


��Right Right mandibularmandibular

dentition exhibiting dentition exhibiting

44 erupted erupted bicuspidbicuspid

�� Natal teethNatal teeth :accessory :accessory

teeth that may be teeth that may be

present present at birthat birth

Neonatal teethNeonatal teeth : are : are


�� Neonatal teethNeonatal teeth : are : are

those arising those arising within within 3030

days of lifedays of life

��Supernumerary teeth may Supernumerary teeth may prevent the eruptionprevent the eruption

or causeor cause malpositionmalposition oror resorptionresorption of adjacent of adjacent

teeth , and may develop teeth , and may develop dentigerous cystsdentigerous cysts


teeth , and may develop teeth , and may develop dentigerous cystsdentigerous cysts

22--Developmental alteration in the sizeDevelopmental alteration in the size

�� Tooth size is variable among different races and Tooth size is variable among different races and

between sexes between sexes

��MacrodontiaMacrodontia : teeth larger than average {i.e. : teeth larger than average {i.e.

physically larger than normal }physically larger than normal }physically larger than normal }physically larger than normal }

��MicrodontiaMicrodontia : unusual small teeth { i.e. : unusual small teeth { i.e.

physically smaller than usual}physically smaller than usual}

Developmental alteration in the sizeDevelopmental alteration in the size

�� Generalized Generalized MacrodontiaMacrodontia has been noted in has been noted in

associationassociation1. Pituitary gigantism

2.Facial hemihypertrophy

�� GeneralizedGeneralized MicrodontiaMicrodontia has been noted in has been noted in

association with :association with :1.1. Pituitary dwarfism Pituitary dwarfism

2.2.Down syndromeDown syndrome

2.Facial hemihypertrophy


�� MacrodontiaMacrodontia affecting affecting single toothsingle tooth is is

uncommonuncommon

�� MicrodontiaMicrodontia involving a involving a single toothsingle tooth is is

more commonmore common than generalized than generalized microdontiamicrodontiamore commonmore common than generalized than generalized microdontiamicrodontia

�� Most Most commonly affectedcommonly affected teethteeth

1.1. Maxillary lateral incisorsMaxillary lateral incisors

2.2. Third molarsThird molars

NB. Both maxillary lateral incisors and third molars are among

the most common teeth to be congenitally missing


��The The maxillary lateral incisormaxillary lateral incisor

appear as : appear as : Peg shapedPeg shaped crowns crowns

overlying a normal root length . overlying a normal root length .

TheThe mesiodistalmesiodistal diameter is reduced diameter is reduced

thethe proximal surfacesproximal surfaces converge converge

towards the towards the incisalincisal edgeedgetowards the towards the incisalincisal edgeedge

��The The maxillary molarmaxillary molar appears appears

small but normally shapedsmall but normally shaped

�� Maxillary lateralMaxillary lateral

�� 22ndnd premolarpremolar

�� 33rdrd molarmolar


�� PremolarPremolar

�� 44thth molarmolar

��HypodontiaHypodontia

�� SupplementalSupplemental


�� 33rd molarrd molar

oo MesiodensMesiodens

oo ParamolarParamolar

oo distomolardistomolar

��MicrodontiaMicrodontia

oo supernumerarysupernumerary

��FusionFusion ,,geminationgemination ,,concrescencconcrescence: e:

terms used for teeth joined together terms used for teeth joined together

33--Developmental alterations in the Developmental alterations in the

shape of teethshape of teeth

terms used for teeth joined together terms used for teeth joined together

based on the based on the suspected suspected aetiologyaetiology

Developmental alterations in the Developmental alterations in the

shape of teethshape of teeth�� FusionFusion ::unionunion between the dentine & or between the dentine & or

the enamel of the enamel of two separatetwo separate developing developing teeth teeth

�� GeminationGemination :: partial development of two partial development of two �� GeminationGemination :: partial development of two partial development of two teeth from a teeth from a single tooth budsingle tooth bud followingfollowingincompleteincomplete divisiondivision

�� ConcrescenceConcrescence :it is the:it is the unionunion of of two teeth two teeth by by cementumcementum iit is not a developmental t is not a developmental anomaly it occurs after root development anomaly it occurs after root development caused bycaused by trauma trauma or adjacent tooth or adjacent tooth malpositionmalposition & crowding of teeth& crowding of teeth

Bifid crown

Fusion Gemination Concrescence

�� DistinctionDistinction between gemination and fusion is between gemination and fusion is made made by countingby counting the number of teeth in the the number of teeth in the dentitiondentition

�� In case of fusionIn case of fusion their their number is number is decreaseddecreased by by


shape of teethshape of teeth

�� In case of fusionIn case of fusion their their number is number is decreaseddecreased by by one as two teeth are replaced by one single one as two teeth are replaced by one single abnormally formed fusion productabnormally formed fusion product

�� In case of geminationIn case of gemination , the , the number is number is normalnormalbut with one of the teeth being replaced by an but with one of the teeth being replaced by an abnormally formed oneabnormally formed one

�� Fusion :Fusion : bilateralbilateral double double

teeth in the place of the teeth in the place of the

mandibularmandibular lateral incisorslateral incisors

and and cuspidscuspidsand and cuspidscuspids

�� Bilateral geminationBilateral gemination : Maxillary central : Maxillary central

incisorsincisors

?

BA BA

concrescenceconcrescence

Accessory cusps Accessory cusps

Three different pattern are recognizedThree different pattern are recognized

�� Cusp of Cusp of CarabelliCarabelli : located : located on the on the palatal palatal surface of surface of the the mesiolingualmesiolingual cusp cusp of a of a maxillarymaxillary molarmolar

�� Talon cusp Talon cusp :: located on thelocated on thelinguallingual aspect of aspect of anterioranterior teethteethwhich resembles an eagle talonwhich resembles an eagle talonlinguallingual aspect of aspect of anterioranterior teethteethwhich resembles an eagle talonwhich resembles an eagle talon

�� Central tubercleCentral tuberclean accessory cusp on an accessory cusp on the the occlusalocclusal surface surface between the between the buccalbuccal & & lingual cusps of lingual cusps of permanent permanent premolars premolars or molarsor molars

Part of the enamel

organ invaginate into

the papillae

dens in dente} dens in dente} {{vaginatusvaginatusininDens Dens

vaginatusvaginatusee&Dens &Dens

the papillae

producing enamel

lined cavity which

communicates to the

surface

Ouward

exageration of an

area of inner

enamel

epithelium&

adjacent

odontogenic

mesenchyme

EO

DP

Inner

epithelium

Dens invaginatus {dens in dente} Dens invaginatus {dens in dente}

&Dens evaginatus&Dens evaginatus

�� Dens Dens invaginatusinvaginatus {{dens in dentedens in dente}: }: duedue to to invaginationinvagination of an area of the of an area of the inner enamelinner enamelepitheliumepithelium into the dental papillae during into the dental papillae during odontogenesisodontogenesis resulting in the formation of resulting in the formation of enamel lined cavity which communicates with enamel lined cavity which communicates with enamel lined cavity which communicates with enamel lined cavity which communicates with the surfacethe surface

�� Dens Dens evagenatusevagenatus : : duedue to proliferation & to proliferation & evaginationevagination of an area of of an area of inner enamel inner enamel epitheliumepithelium & adjacent & adjacent odontogenicodontogenicmesenchymemesenchyme

Dens invaginatus {dens in dente}Dens invaginatus {dens in dente}

�� The The depth of depth of invaginationinvagination varies from a varies from a slightslightenlargement of the enlargement of the cingulumcingulum pitpit{{e.ie.i. . exagerationexageration of the pit } of the pit } to a to a deep deep infoldinginfolding that that extends to the apexextends to the apexextends to the apexextends to the apex

�� In the interior of the tooth, the pit In the interior of the tooth, the pit dilates to form a dilates to form a large cavitylarge cavity

�� Through this pitThrough this pitbacteria bacteria from the oral cavity have free access to the from the oral cavity have free access to the inner part of the tooth which makes it vulnerable for inner part of the tooth which makes it vulnerable for carious decaycarious decay

�� When dentine & enamel When dentine & enamel

forming tissue forming tissue invaginateinvaginate

the whole length of a the whole length of a

tooth {tooth {e.i.whene.i.when

Dens invaginatus {dens in dente}Dens invaginatus {dens in dente}

tooth {tooth {e.i.whene.i.when

invaginationinvagination is large} it is large} it

appears appears radiographicallyradiographically as as

a tooth within a tootha tooth within a tooth

{ { dens in dentedens in dente}}

�� A small A small nodule of enamelnodule of enamel formed on formed on

the root surface near the the root surface near the amelocementalamelocemental

junction , on junction , on maxillary molarsmaxillary molars at the at the

furcationfurcation areaarea

This may result from This may result from

Enamel pearl or enameloma

{ectopic enamel}

�� This may result from This may result from

cells of cells of HertwigHertwig’’ss sheath which have sheath which have become differentiated into become differentiated into ameloblastameloblast

�� Occasionally Occasionally

containing containing

minute horn of minute horn of

small pulpsmall pulp

Taurodontism {bull like tooth}Taurodontism {bull like tooth}

�� Elongated Elongated crownscrowns & & apically displaced apically displaced

furcationfurcation {i.e. tends to be rectangular}{i.e. tends to be rectangular}

�� Resulting in Resulting in pulp chamberpulp chamber that have that have

increasedincreased apicalapical--occlusalocclusal heightheight

�� This condition is due to This condition is due to failure of epithelial root failure of epithelial root

sheath of sheath of hertwighertwig’’ssto to invaginateinvaginateat properat proper

horizontal horizontal

directiondirection

Dilaceration Dilaceration

�� Abnormal Abnormal angulationangulation or bend in the rootor bend in the root

�� The most The most comonlycomonly affected teeth are the affected teeth are the

maxillary central incisorsmaxillary central incisors

DilacerationDilaceration

�� The causeThe cause :trauma during root development :trauma during root development

�� Movement Movement of the crown or the crown & part of of the crown or the crown & part of

the root {the root {i.e. calcified parti.e. calcified part } } from from the remaining the remaining

developing root {developing root {i.e. not yet calcifiedi.e. not yet calcified} may } may

result in sharp angulation after the tooth result in sharp angulation after the tooth

completes developmentcompletes development

Normal enamel is formed in Normal enamel is formed in 3 3 stagesstages

�� 11. . Formative stageFormative stage : : ameloblastsameloblasts deposit deposit

organicorganic matrix normal matrix normal thicknessthickness of of

enamelenamel

�� 22.Calcification stage.Calcification stage : : mineralizationmineralization of of �� 22.Calcification stage.Calcification stage : : mineralizationmineralization of of

enamel matrix by enamel matrix by formation of crystals formation of crystals & & removal removal of of

the majority of the original the majority of the original proteinsproteins

�� 33. . Maturation stageMaturation stage : : crystals enlarges crystals enlarges & &

mature mature withdrawal of organic withdrawal of organic component component

Normal thickness

Hypoplastic

enamel

Hypocalcified

enamal

Formative stage

Calcificationstage

Inadequate formation of enamel

matrix .Enamel is reduced in

quantity but is of normal

hardness.{irregular, pitted, thin or vertical grooves}

A defect not in the quantitybut in the quality of enamel

It is poorly mineralized soft& chips & wears easily

1st Enamel is opaque {dull, white}& soft

Then Enamel becomes hard & translucent

Maturation

stage

Hypomaturation

of enamel

& chips & wears easily

A defect in the crystal

structure of enamel leads to a

mottled enamel with white to brown to yellow

Amelogenesis imperfectaAmelogenesis imperfecta

�� It is aIt is a geneticallygenetically determined defect of enamel determined defect of enamel

formationformation

�� 1616 different hereditary subtypes exist with different hereditary subtypes exist with

numerous numerous patterns of inheritance patterns of inheritance {{autosomalautosomalnumerous numerous patterns of inheritance patterns of inheritance {{autosomalautosomal

dominant , dominant , recessiverecessive or or sex linkedsex linked

�� DeciduousDeciduous & & permanentpermanent teeth are involved teeth are involved

but not to the same extent but not to the same extent

11--Hypoplastic Hypoplastic amelogenesisamelogenesis

imperfectaimperfecta

��DefectiveDefective organic matrixorganic matrix

formation {quantitative formation {quantitative

defect}defect}

��ThicknessThickness of enamel is of enamel is less less

than normalthan normal

��IrregularIrregular enamel , enamel , thin thin ,,

pittedpitted or or vertical groovesvertical grooves

�� CalcificationCalcification & &

maturation maturation is is normalnormal

pittedpitted or or vertical groovesvertical grooves

��Pits allow stains Pits allow stains to to

accumulate causing accumulate causing

discolorationdiscoloration

�� NormalNormal hardnesshardness& &

translucencytranslucency

�� RadiographicallyRadiographically enamel shows enamel shows

normal normal radiopacityradiopacity

Amelogenenesis imperfectaAmelogenenesis imperfecta

{sex linked dominant type}{sex linked dominant type}

�� Typical Typical vertical vertical

ridged enamelridged enamel

�� HypoplasticHypoplastic

amelogenesisamelogenesis

imperfectaimperfecta pitted pitted

patternpattern

�� Rough pattern . Small Rough pattern . Small

yellow teeth with yellow teeth with

rough enamel surface , rough enamel surface ,

open contact pointsopen contact points

Hypoplastic amelogenesis Hypoplastic amelogenesis


open contact pointsopen contact points

22--Hypocalcified Hypocalcified amelogenesisamelogenesis


�� Normal quantityNormal quantity of of enamel matrixenamel matrix

��Failure in normal Failure in normal

�� Normal thicknessNormal thickness & & shapeshape in in

newly newly erupted teeth erupted teeth onlyonly

��Enamel Enamel softsoft to probe to probe abrades abrades

easilyeasily exposing the dentine exposing the dentine to to ��Failure in normal Failure in normal calcification calcification

easilyeasily exposing the dentine exposing the dentine to to

wear down wear down rapidlyrapidly to level of to level of

gumgum lineline {shoulder form}{shoulder form}

��The color The color variesvaries from from whitewhite

opaqueopaque to to yellow yellow to to brownbrown

��Enamel has Enamel has similar densitysimilar density to to

dentin on radiograph dentin on radiograph

Hypomaturation amelogenesis Hypomaturation amelogenesis

imperfectaimperfecta�� Normal Normal enamel enamel matrixmatrix

which which beginsbegins to to

mineralizemineralize

��The defect is in the The defect is in the

maturationmaturation of the of the

�� Teeth are Teeth are normalnormal in shape & in shape &

thicknessthickness

��MottledMottled,, opaque opaque , , whitewhite--brown brown

yellowyellow discolorationdiscoloration

��Enamel is Enamel is softer softer than normal, than normal, maturationmaturation of the of the

enamelenamel’’s crystals crystal structurestructure��Enamel is Enamel is softer softer than normal, than normal,

can be pierced by probe can be pierced by probe under under

pressurepressure & & attrition attrition occurs occurs

but but not not as severely as in the as severely as in the

hypocalcifiedhypocalcified typetype

��RadiodensityRadiodensity similar similar to dentinto dentin

�Commonly seen in permanent teeth in which the

overlying deciduous tooth becomes abscessed or

physically forced into the enamel organ of the

Environmental factors affecting Environmental factors affecting

developing teethdeveloping teeth

I. Local factors a.Trauma b. Infection {abscess}

physically forced into the enamel organ of the

permanent tooth

�Ameloblasts overlying the developing crown are

affected resulting in enamel hypocalcification or

hypoplasia

�Affected tooth may have areas of coronal discoloration

or pits& irrigularities {turner’tooth}

environmental factors affecting environmental factors affecting

developing teethdeveloping teeth

1. Congenital syphilis

2. Ingestion of chemicals {fluorides , tetracycline}

II.II. Systemic factorsSystemic factors

tetracycline}

3. Nutritional deficiency {Vit .A , D , calcium, phosphorus

4. Exanthematous fevers {Scarlet fever , measles, chicken pox}

5. General diseases ex. Rickets , Down syndrome Cleidocranial dysplasia

Acquired {environmental} alterations in the Acquired {environmental} alterations in the

structure of enamelstructure of enamel

To differentiate between developmental & acquired

alterations that may affect the tooth you must notice the

following :

Hereditary Environmental

�� Affect Affect bothboth deciduousdeciduous & &

permanentpermanent

�� Affect Affect eithereither the enamel the enamel

or the dentineor the dentine

�� Produce Produce diffuse diffuse or or

verticallyvertically oriented oriented

defects defects

�� Affect Affect onlyonly one dentition one dentition

{{permanentpermanent>deciduous}>deciduous}

�� Affects Affects bothboth enamel enamel & &

dentinedentine

�� Produce Produce horizontalhorizontal

oriented defectsoriented defects

�Enamel hypoplasia

following a pattern sugestive of

systemic problem such as

high fever

Fluorosis {mottled enamel}Fluorosis {mottled enamel}

�� Seen in people who grow up in areas where the Seen in people who grow up in areas where the

water supply contains a large amount of water supply contains a large amount of

fluorides fluorides more more than than 11ppmppm

�� OverdoseOverdose of fluorides interferes with the of fluorides interferes with the �� OverdoseOverdose of fluorides interferes with the of fluorides interferes with the

function function of of amelobastsamelobasts & & calcification calcification of the of the

enamel matrixenamel matrix

�� Defect rangeDefect range from from small white spotssmall white spots to white to white

opaque areasopaque areas to to darkly staineddarkly stained & & pittedpitted enamelenamel

FluorosisFluorosis {mottled enamel{mottled enamel}}

The extent of damage is dependent on the duration

timing & concentration of fluoride

Congenital syphilisCongenital syphilis

�� Prenatal syphilis is due to Prenatal syphilis is due to maternal infectionmaternal infection

��If the fetus is infected , early abortion occurs If the fetus is infected , early abortion occurs

��Later fetal infection results in infant born with Later fetal infection results in infant born with stigmatastigmata or congenital syphilisor congenital syphilisstigmatastigmata or congenital syphilisor congenital syphilis

��The The permanentpermanent teeth are affectedteeth are affected

��Because Because spirochetes spirochetes do not enter the do not enter the circulation until the circulation until the 1616thth week of intrauterine life week of intrauterine life {deciduous teeth has completely formed by the {deciduous teeth has completely formed by the end of the end of the 1616thth week}week}

Congenital syphilisCongenital syphilis�� A A . . Mulberry molarMulberry molar : the : the 11stst molar molar

may be dome shaped {moon molar} . may be dome shaped {moon molar} .

Its Its occlusalocclusal surface exhibit multiple surface exhibit multiple

irregular tuberclesirregular tubercles replacing normal replacing normal

cuspscusps

�� B . B . HutchinsonHutchinson’’s teeth {upper s teeth {upper �� B . B . HutchinsonHutchinson’’s teeth {upper s teeth {upper

incisorsincisors}}

�Barrel shaped teeth

�Mesio & distal convergence

in incisal half of teeth

�Mesial & distal angles are rounded

�Notch in the middle of incisor edge

Tetracycline pigmentationTetracycline pigmentation

1.1. Tetracycline binds to the Tetracycline binds to the

calcifying tissue calcifying tissue stains stains

the developing teeth &bonethe developing teeth &bone

2.2. Tetracycline is deposited along Tetracycline is deposited along

the the incremental lines incremental lines of dentine of dentine

& enamel whole tooth may be & enamel whole tooth may be

discolored {bright discolored {bright yellow yellow dirty dirty

greyishgreyish brown brown } }

3.3. Affected teeth Affected teeth exhibit exhibit

fluorescencefluorescence under under

ultraviolet raysultraviolet rays


dentinedentine of the toothof the tooth

1.1. DentinogenesisDentinogenesis imperfectaimperfecta

2.2. Dentinal dysplasia{rootless teeth} Dentinal dysplasia{rootless teeth}

3.3. Regional Regional odontodysplasiaodontodysplasia {ghost cells}{ghost cells}3.3. Regional Regional odontodysplasiaodontodysplasia {ghost cells}{ghost cells}

4.4. Shell teethShell teeth

DentinogenesisDentinogenesis imperfectaimperfecta

�� Uncommon defect of Uncommon defect of collagen collagen formation formation

transmitted as an transmitted as an autosomalautosomal dominant traitdominant trait

��Both dentitionBoth dentition are affectedare affected

��Dentin is Dentin is softsoft and has an and has an abnormal high water abnormal high water ��Dentin is Dentin is softsoft and has an and has an abnormal high water abnormal high water

contentcontent

�� Appears alone or associated with Appears alone or associated with osteogenesisosteogenesis


Dentinogenesis imperfectaDentinogenesis imperfecta

1.1. Tooth crown shows Tooth crown shows amber amber coloration coloration {{blue brown } blue brown } or opalescent or opalescent {abnormally {abnormally transluscenttransluscent }}{abnormally {abnormally transluscenttransluscent }}

2.2. Bulbous crownBulbous crown & & short rootsshort roots

DentinogenesisDentinogenesis imperfectaimperfecta

�� Absence of scallopingAbsence of scalloping between enamel and between enamel and dentine flat ADJ dentine flat ADJ union betweenunion between enamel enamel and dentine is and dentine is defectivdefective e enamel chipsenamel chips away away soft dentinesoft dentine will be will be exposed exposed rapidly wear rapidly wear offoff worn down to gum levelworn down to gum level by by

3.Absence of scalloping

offoff worn down to gum levelworn down to gum level by by adolescenceadolescence

Some enamel remains around

the necks of the posterior

teeth

4.4. Pulp chamberPulp chamber is is obliteratedobliterated by by continuous formation of the continuous formation of the imperfect dentineimperfect dentine

Dentinogenesis imperfectaDentinogenesis imperfecta

imperfect dentineimperfect dentine

Picrothinonin stain

Remnants of pulp

chamber

Dentine dysplasia {rootless teeth}Dentine dysplasia {rootless teeth}

1.1. Characterized by teeth with Characterized by teeth with veryvery

short rootsshort roots

2.2. ObliterationObliteration of the pulpof the pulp

chamber by fused chamber by fused rounded rounded

nodulesnodules of poorly formed of poorly formed nodulesnodules of poorly formed of poorly formed

dentinedentine

��The teeth are typically The teeth are typically lost earlylost early in in

life life becausebecause of the of the weak support weak support

given by the short rootsgiven by the short roots or or

periapicalperiapical inflammatory lesionsinflammatory lesions

Regional Regional odontodysplasiaodontodysplasia {{ghost ghost

teeth}teeth}

�� Unknown cause Unknown cause

��Involves Involves deficienciesdeficiencies of all the hard of all the hard

tissues of the teeth {tissues of the teeth {enamelenamel

dentinedentine & & cementumcementum }}

��Tissues are Tissues are thinthin, , poorly poorly

mineralizedmineralized & are & are

described as described as ghost teethghost teeth

radiographicallyradiographically

�� The poor quality of the The poor quality of the

affected teeth make them affected teeth make them of little of little

useuse

Shell teethShell teeth

�� Excessively large pulp chamberExcessively large pulp chamber

�� After the formation of a After the formation of a thin thin

layerlayer of dentineof dentine the formation of the formation of

dentine ceases & results in a dentine ceases & results in a veryvery

large pulp chamberlarge pulp chamber surrounded surrounded large pulp chamberlarge pulp chamber surrounded surrounded

by a by a thin shellthin shell of dentineof dentine

�� Enamel is normalEnamel is normal

��Variant of Variant of dentinogenesisdentinogenesis


��Transmitted through the same Transmitted through the same

genegene

�� Normal thickness of enamel ,extremely thin Normal thickness of enamel ,extremely thin

dentine& dramatically enlarged pulpdentine& dramatically enlarged pulp

Shell teethShell teeth

Normal pulp

Developmental Disturbances of Teeth

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