developmental disturbances of teeth
TRANSCRIPT
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
11--Disturbances in number of teethDisturbances in number of teeth
��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
?
Disturbances in number of teethDisturbances in number of teeth
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, ,
11--Disturbances in number of teethDisturbances in number of teeth
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
Disturbances in number of teethDisturbances in number of teeth
fourth molarfourth molar
ParamolarParamolar ::a posterior tooth a posterior tooth situated situated linguallylinguallyor or buccallybuccally to a molarto a molar
Disturbances in number of teethDisturbances in number of teeth
MesiodensMesiodens
��SupplementalSupplemental
��lateral incisorslateral incisors
Disturbances in number of teethDisturbances in number of teeth
��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
11--Disturbances in number of teethDisturbances in number of teeth
�� 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
Disturbances in number of teethDisturbances in number of teeth
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
Developmental alteration in the sizeDevelopmental alteration in the size
�� 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
Developmental alteration in the sizeDevelopmental alteration in the size
��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
�� Maxillary lateralMaxillary lateral
�� PremolarPremolar
�� 44thth molarmolar
��HypodontiaHypodontia
�� SupplementalSupplemental
�� Maxillary lateralMaxillary lateral
�� 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
Developmental alterations in the Developmental alterations in the
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
imperfectaimperfecta
open contact pointsopen contact points
22--Hypocalcified Hypocalcified amelogenesisamelogenesis
imperfectaimperfecta
�� 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
Developmental alterations in the Developmental alterations in the
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
imperfectaimperfecta
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
imperfectaimperfecta
��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