disorders of development of teeth. may be prenatal or postnatal in origin may be prenatal or...

DISORDERS OF DISORDERS OF DEVELOPMENT OF DEVELOPMENT OF

TEETHTEETH

May be prenatal or postnatal in originMay be prenatal or postnatal in origin May be inherited or acquiredMay be inherited or acquiredCausesCauses : : Abnormalities in the differentiation of the Abnormalities in the differentiation of the

dental lamina and the tooth germs leading dental lamina and the tooth germs leading to anomalies in the number, the size and to anomalies in the number, the size and shape of teeth (abnormalities of shape of teeth (abnormalities of morphodifferentiation)morphodifferentiation)

Abnormalities in the formation of the dental Abnormalities in the formation of the dental hard tissues leading to disturbances in tooth hard tissues leading to disturbances in tooth structure (abnormalities of histodifferention).structure (abnormalities of histodifferention).

DISTURBANCES IN NUMBER DISTURBANCES IN NUMBER OF TEETH.OF TEETH.

ANODONTIA=ANODONTIA= Absence of teeth Absence of teeth May be :May be :

– Complete anodontiaComplete anodontia– Partial anodontia (hypodontia)Partial anodontia (hypodontia)– Pseudoanodontia : Absent teeth Pseudoanodontia : Absent teeth

because of impaction or delayed because of impaction or delayed eruptioneruption

– False anodontia : When teeth have False anodontia : When teeth have been exfoliated or extractedbeen exfoliated or extracted

NUMBER (cont…)NUMBER (cont…)

Partial anodontia is relatively Partial anodontia is relatively common, mostly third molars, common, mostly third molars, followed by second premolars and followed by second premolars and maxillary lateral incisors.maxillary lateral incisors.

Complete anodontia is rare but is Complete anodontia is rare but is often associated with hereditary often associated with hereditary ectodermal dysplasia (hypohidrotic ectodermal dysplasia (hypohidrotic ectodermal dysplasia).ectodermal dysplasia).

NUMBER (cont…)NUMBER (cont…)

SUPERNUMERARY TEETH.SUPERNUMERARY TEETH. May have a normal morphology : Supplementary May have a normal morphology : Supplementary

teethteeth May be rudimentary and miniatureMay be rudimentary and miniatureCauses:Causes: HereditaryHereditary Syndrome associated (cleft palate or cleidocranial Syndrome associated (cleft palate or cleidocranial

dysplasia)dysplasia)Location:Location: Most frequently in the anterior and molar regions Most frequently in the anterior and molar regions

of the maxilla, followed by the premolar region of of the maxilla, followed by the premolar region of the mandiblethe mandible

Permanent dentition more affected than primary ; Permanent dentition more affected than primary ; females more affected than males.females more affected than males.

SUPERNUMERARY SUPERNUMERARY TEETH(cont…).TEETH(cont…).

Significance:Significance: Supernumerary teeth occupy space, may prevent Supernumerary teeth occupy space, may prevent

the eruption of other teeth.the eruption of other teeth. May erupt into the buccal or lingual embrasure or May erupt into the buccal or lingual embrasure or

outside the line of the dental archoutside the line of the dental arch May cause delayed eruption, maleruption and May cause delayed eruption, maleruption and

malalignment of other teethmalalignment of other teeth InaestheticInaesthetic If between the roots of adjacent teeth, they cause If between the roots of adjacent teeth, they cause

diastemadiastema Resorption of adjacent teethResorption of adjacent teeth May develop into dentigerous cysts if uneruptedMay develop into dentigerous cysts if unerupted

SUPERNUMERARY SUPERNUMERARY TEETH(cont…).TEETH(cont…).

Mesiodens: Mesiodens: These are supernumerary teeth occurring between These are supernumerary teeth occurring between

central incisorscentral incisors Most common of all the supernumerary teethMost common of all the supernumerary teeth They mostly occur between the maxillary central They mostly occur between the maxillary central

incisorsincisorsNatal teeth:Natal teeth: Supernumerary teeth appearing at the time of birthSupernumerary teeth appearing at the time of birth Very rareVery rare Not to be confused with prematurely erupted Not to be confused with prematurely erupted

deciduous teeth and eruption cysts or false teethdeciduous teeth and eruption cysts or false teeth Usually mandibular central incisorsUsually mandibular central incisors

DISTURBANCES IN SIZE OF DISTURBANCES IN SIZE OF TEETHTEETH

MICRODONTIA.MICRODONTIA.May be May be Generalized or localizedGeneralized or localized True microdontia when teeth are measurably True microdontia when teeth are measurably

smaller than normal (in pituitary dwarfism)smaller than normal (in pituitary dwarfism) Relative microdontia in comparison with a large Relative microdontia in comparison with a large

mandible and maxillamandible and maxilla Usually the shape is also alteredUsually the shape is also altered Commonly seen with the maxillary lateral Commonly seen with the maxillary lateral

incisors= peg shaped laterals, followed by incisors= peg shaped laterals, followed by maxillary 3rd molars and supernumerary teethmaxillary 3rd molars and supernumerary teeth

Causes: Usually hereditary in originCauses: Usually hereditary in originSignificance: Only cosmeticSignificance: Only cosmetic

SIZE (cont…)SIZE (cont…)MACRODONTIA.MACRODONTIA.

May be generalized:May be generalized: Absolute macrodontia as seen in pituitary gigantismAbsolute macrodontia as seen in pituitary gigantism Relative macrodontia when seen on a disproportionately Relative macrodontia when seen on a disproportionately

small maxilla and mandiblesmall maxilla and mandibleMay also be localized:May also be localized: Abnormally large tooth or group of teethAbnormally large tooth or group of teeth Relatively uncommon conditionRelatively uncommon condition Usually seen with mandibular 3rd molars, incisor and Usually seen with mandibular 3rd molars, incisor and

canine region.canine region.

Hemifacial hypertrophyHemifacial hypertrophy: : The teeth on the affected side are abnormally large The teeth on the affected side are abnormally large

compared with the unaffected side compared with the unaffected side

DISTURBANCES IN SHAPE DISTURBANCES IN SHAPE OF TEETH.OF TEETH.

May involve the crown, the root or bothMay involve the crown, the root or both

GEMINATION.GEMINATION.Definition:Definition: This is a fusion of two teeth from a single enamel organ This is a fusion of two teeth from a single enamel organ

resulting either in:resulting either in: Partial cleavage leading to two crowns that share the same Partial cleavage leading to two crowns that share the same

root and same pulp canalroot and same pulp canal Complete cleavage making twinning (2 teeth from one Complete cleavage making twinning (2 teeth from one

tooth germ)tooth germ)The cause is unknown but trauma has been suggested The cause is unknown but trauma has been suggested as a possible causeas a possible causeSignificance:Significance:- InaestheticInaesthetic- May cause crowding of teethMay cause crowding of teeth

SHAPE (cont…)SHAPE (cont…)FUSION.FUSION.Definition:Definition: It is the joining of two developing tooth germs, resulting It is the joining of two developing tooth germs, resulting

in a single large tooth.in a single large tooth. The fusion process may involve the entire length of the The fusion process may involve the entire length of the

tooth or the roots only; in that case, cementum and tooth or the roots only; in that case, cementum and dentin are shared. Root canals may also be separate or dentin are shared. Root canals may also be separate or shared. May also involve the crown only.shared. May also involve the crown only.

The fusion must involve the dentin because, when 2 teeth The fusion must involve the dentin because, when 2 teeth are connected only by cementum, the condition is termed are connected only by cementum, the condition is termed “concrescence”“concrescence”

It may be impossible to differentiate fusion of normal or It may be impossible to differentiate fusion of normal or supernumerary teeth from germination.supernumerary teeth from germination.

The cause is unknown but trauma has been suggestedThe cause is unknown but trauma has been suggested

SHAPE (cont…) SHAPE (cont…) CONCRESCENCE.CONCRESCENCE.Definition:Definition: It is a form of fusion in which the adjacent, already formed It is a form of fusion in which the adjacent, already formed

teeth are joined by cementum. It is an acquired anomalyteeth are joined by cementum. It is an acquired anomaly This may take place before or after eruption of teethThis may take place before or after eruption of teeth Most commonly seen in association with the maxillary Most commonly seen in association with the maxillary

second and third molarssecond and third molarsCauses: Causes: Believed to be related to trauma or overcrowdingBelieved to be related to trauma or overcrowding Most frequently seen in the permanent dentition where Most frequently seen in the permanent dentition where

the roots develop close togetherthe roots develop close together Hypercementosis associated with chronic inflammationHypercementosis associated with chronic inflammationSignificance:Significance: None unless one of the teeth involved requires extraction. None unless one of the teeth involved requires extraction.

Surgical sectioning may be required to save the other Surgical sectioning may be required to save the other tooth.tooth.

SHAPE (cont…)SHAPE (cont…)

DILACERATION.DILACERATION.Definition:Definition: It is an extraordinary curving or angulation of It is an extraordinary curving or angulation of

tooth roots.tooth roots.Causes:Causes: Trauma during root developmentTrauma during root development Hereditary factorsHereditary factors Lack of space for developmentLack of space for developmentSignificance:Significance: Eruption generally continues without problemsEruption generally continues without problems Extraction may be difficultExtraction may be difficult Root canal treatment may be challengingRoot canal treatment may be challenging

SHAPE (cont…)SHAPE (cont…)DENS INVAGINATUS.DENS INVAGINATUS.

Definition:Definition: Also known as dens in dente, it is an uncommon tooth Also known as dens in dente, it is an uncommon tooth

anomaly that represents an exaggeration or accentuation anomaly that represents an exaggeration or accentuation of the lingual pit. Can range from superficial (only the of the lingual pit. Can range from superficial (only the crown affected) to deep (crown and root involved).crown affected) to deep (crown and root involved).

Permanent maxillary lateral incisors most commonly Permanent maxillary lateral incisors most commonly involvedinvolved

Any anterior tooth may be affectedAny anterior tooth may be affected Bilateral involvement commonly seenBilateral involvement commonly seenCause:Cause: UnknownUnknown Genetic factors believed to be involved in small Genetic factors believed to be involved in small

percentages of cases percentages of cases


Complications:Complications: Predisposes the tooth to early decay and Predisposes the tooth to early decay and

subsequent pulpitissubsequent pulpitis

Management:Management: Prophylactic filling of the pit is Prophylactic filling of the pit is

recommended to avoid these complicationsrecommended to avoid these complications When pulpitis has led to nonvitality, When pulpitis has led to nonvitality,

endodontic procedures may salvage the endodontic procedures may salvage the affected toothaffected tooth


DENS EVAGINATUS.DENS EVAGINATUS.

Definition:Definition: This is a relatively common developmental This is a relatively common developmental

condition characterized by an anomalous condition characterized by an anomalous tubercle, or cusp, often bilateral, located in the tubercle, or cusp, often bilateral, located in the center of the occlusal surface. The premolar center of the occlusal surface. The premolar teeth are predominantly affected.teeth are predominantly affected.

Causes:Causes: It is unknown but race related because it has It is unknown but race related because it has

been reported almost exclusively in Asians and been reported almost exclusively in Asians and Native Americans.Native Americans.


Complications:Complications: There can be an early exposure of an accessory There can be an early exposure of an accessory

pulp horn extending into the tubercle due to pulp horn extending into the tubercle due to quick occlusal abrasion.quick occlusal abrasion.

Periapical pathology in young caries-free teeth Periapical pathology in young caries-free teeth often before completion of root development and often before completion of root development and apical closure making root canal fillings apical closure making root canal fillings challengingchallenging

Management:Management: Grinding the opposing tooth or the tubercle to Grinding the opposing tooth or the tubercle to

stimulate secondary dentin formation in order to stimulate secondary dentin formation in order to prevent the periapical syndrome.prevent the periapical syndrome.

SHAPE (cont…)SHAPE (cont…)TAURODONTISM.TAURODONTISM.

Definition:Definition: A taurodont tooth(bull-like tooth) is one in which the pulp chamber A taurodont tooth(bull-like tooth) is one in which the pulp chamber

has a greater apico-occlusal height than in normal teeth, whith no has a greater apico-occlusal height than in normal teeth, whith no constriction at the level of the amelo-cemental junction; the constriction at the level of the amelo-cemental junction; the chamber extends apically well beyond the cervix.chamber extends apically well beyond the cervix.

It affects multirooted teeth and is rare in primary dentitionIt affects multirooted teeth and is rare in primary dentitionCauses:Causes: Failure of Hertwig’s sheath to invaginate at the proper horizontal Failure of Hertwig’s sheath to invaginate at the proper horizontal

levellevel Can be seen as an isolated incident or in association with Can be seen as an isolated incident or in association with

syndromes such as Down’s syndrome and Klinefelter’s syndrome.syndromes such as Down’s syndrome and Klinefelter’s syndrome. Genetic factors (high prevalence in Eskimos and Middle Eastern Genetic factors (high prevalence in Eskimos and Middle Eastern

population)population)Significance:Significance: Little clinical significance, no treatment requiredLittle clinical significance, no treatment required Aesthetic concernAesthetic concern


SUPERNUMERARY ROOTS.SUPERNUMERARY ROOTS.

Definition:Definition: These are accessory roots commonly seen in These are accessory roots commonly seen in

mandibular canines, premolars and molars. mandibular canines, premolars and molars. They are rarely seen in upper anterior teeth and They are rarely seen in upper anterior teeth and mandibular incisorsmandibular incisors

Significance:Significance: When extractions or root canal fillings are When extractions or root canal fillings are

necessary, radiographic recognition of an necessary, radiographic recognition of an extraordinary number of roots becomes extraordinary number of roots becomes important.important.

SHAPE (cont…)SHAPE (cont…)ENAMEL PEARLS.ENAMEL PEARLS.

Definition:Definition: These are small masses of enamel found apically to the These are small masses of enamel found apically to the

amelocemental junction.amelocemental junction. They occur most commonly in the bifurcation or trifurcation They occur most commonly in the bifurcation or trifurcation

of teeth but may appear on single-rooted premolar as well.of teeth but may appear on single-rooted premolar as well. Maxillary molars more commonly affected than mandibularMaxillary molars more commonly affected than mandibular Can be detected radigraphicallyCan be detected radigraphicallyCause:Cause: Hertwig’s sheath remains in contact with the dentin and Hertwig’s sheath remains in contact with the dentin and

stimulated to differentiate into functional ameloblasts.stimulated to differentiate into functional ameloblasts.Significance:Significance: Little clinical significance except when located in an area of Little clinical significance except when located in an area of

periodontal disease.periodontal disease.

DISTURBANCES IN DISTURBANCES IN STRUCTURE OF TEETH.STRUCTURE OF TEETH.

DISTURBANCES IN STRUCTURE OF ENAMEL.DISTURBANCES IN STRUCTURE OF ENAMEL. Enamel normally develops in two stages:Enamel normally develops in two stages:

Secretory stageSecretory stage:: Matrix productionMatrix production Initial mineralizationInitial mineralization

Matrix production: Synthesis and secretion of Matrix production: Synthesis and secretion of matrix proteins (amelogenins and enamelins)matrix proteins (amelogenins and enamelins)

Initial mineralization: Appears immediately after Initial mineralization: Appears immediately after secretion, crystals abut the plasmasecretion, crystals abut the plasma

ENAMEL DEFECTS (cont…)ENAMEL DEFECTS (cont…)Maturation stage:Maturation stage:

Withdrawal of water and proteinsWithdrawal of water and proteins Concomittant increase in mineral content before the tooth Concomittant increase in mineral content before the tooth

eruptserupts

Defective amelogenesis can be related either to matrix formation Defective amelogenesis can be related either to matrix formation leading to enamel hypoplasia or to mineralization and leading to enamel hypoplasia or to mineralization and maturation stages leading to hypomineralized enamel.maturation stages leading to hypomineralized enamel.

Enamel Hypoplasia:Enamel Hypoplasia: It is a quantitatively defective enamel, when of normal hardnessIt is a quantitatively defective enamel, when of normal hardness

Enamel hypocalcification:Enamel hypocalcification: It is a qualitatively defective enamel when normal amounts of It is a qualitatively defective enamel when normal amounts of

enamel is produced but are hypomineralized; the enamel is enamel is produced but are hypomineralized; the enamel is softer than normal.softer than normal.

ENAMEL DEFECTS (cont…)ENAMEL DEFECTS (cont…)

The extent of enamel defects depends on The extent of enamel defects depends on three conditions:three conditions:

The intensity of the etiologic factorThe intensity of the etiologic factor The duration of the factor’s presenceThe duration of the factor’s presence The time at which the factor occurs during The time at which the factor occurs during

crown development.crown development.Clinical features:Clinical features: Defects can range from yellowish or Defects can range from yellowish or

brownish pigmentation of the enamel to brownish pigmentation of the enamel to extensive pits and irregularities of the extensive pits and irregularities of the surfacesurface

The crown is usually smaller than normal.The crown is usually smaller than normal.


Localized causes:Localized causes: Local infections or trauma related to Local infections or trauma related to

the deciduous predecessor resulting the deciduous predecessor resulting in damage to the ameloblasts of in damage to the ameloblasts of permanent successor. Such teeth are permanent successor. Such teeth are often called Turner teeth.often called Turner teeth.

RadiotherapyRadiotherapy IdiopathicIdiopathic


General causes:General causes: Environmental/Systemic factors: Can be Environmental/Systemic factors: Can be

either either

Prenatal:- Infections, e.g. rubella, syphilisPrenatal:- Infections, e.g. rubella, syphilis Maternal diseaseMaternal disease Excess fluoride ionsExcess fluoride ions

Neonatal: -Haemolytic disease of the newbornNeonatal: -Haemolytic disease of the newborn HypocalcaemiaHypocalcaemia Premature birth/ Prolonged labourPremature birth/ Prolonged labour


Postnatal:Postnatal: Severe childhood infections especially Severe childhood infections especially

the viral exanthemathe viral exanthema Chronic diseases in childhood e.g. Chronic diseases in childhood e.g.

congenital heart disease, congenital heart disease, gastrointestinal and endocrine diseasesgastrointestinal and endocrine diseases

Nutritional deficiencies e.g. vit DNutritional deficiencies e.g. vit D Cancer chemotherapyCancer chemotherapy Excess fluoride ionsExcess fluoride ions


For systemic factors to have an effect on the For systemic factors to have an effect on the developing permanent teeth, they must developing permanent teeth, they must generally occur after birth and before the age generally occur after birth and before the age of 6 years.of 6 years.

Genetic factors:Genetic factors: Only teeth affected- Amelogenesis imperfectaOnly teeth affected- Amelogenesis imperfecta Teeth affected in association with generalized Teeth affected in association with generalized

defects- Ectodermal dysplasia syndromesdefects- Ectodermal dysplasia syndromes Down’s syndrome (Trisomy 21)Down’s syndrome (Trisomy 21)

ENAMEL DEFECTS (cont…)ENAMEL DEFECTS (cont…)ENAMEL OPACITIES.ENAMEL OPACITIES.

Definition:Definition: These are white spots seen in smooth surface enamel, some of These are white spots seen in smooth surface enamel, some of

which become brown-stained after eruption.which become brown-stained after eruption.

They are most common in children aged 12-14yearsThey are most common in children aged 12-14years Both deciduous and permanent dentitions are affected.Both deciduous and permanent dentitions are affected. Maxillary permanent central incisors most frequently involvedMaxillary permanent central incisors most frequently involved

Causes:Causes: Unknown but are thought to be due to local rather than systemic Unknown but are thought to be due to local rather than systemic

factors factors The prevalence is less in areas with 1 PPM of fluoride in the The prevalence is less in areas with 1 PPM of fluoride in the

drinking waterdrinking water The opaque spots are hypomineralized.The opaque spots are hypomineralized.

ENAMEL DEFECTS (cont…)ENAMEL DEFECTS (cont…) CHRONOLOGICAL HYPOPLASIAS.CHRONOLOGICAL HYPOPLASIAS.

Most enamel hypoplasias due to environmental Most enamel hypoplasias due to environmental causes are of this type. They are time related causes are of this type. They are time related disturbances. E.g. Any serious nutritional deficiency disturbances. E.g. Any serious nutritional deficiency or systemic disease occurring during the time of or systemic disease occurring during the time of formation of teeth.formation of teeth.

The disturbance occurring in utero, at or soon after The disturbance occurring in utero, at or soon after birth may affect the incisal edges of the permanent birth may affect the incisal edges of the permanent central incisors and the occlusal surfaces of the first central incisors and the occlusal surfaces of the first permanent molars, in addition to the deciduous teeth.permanent molars, in addition to the deciduous teeth.


CONGENITAL SYPHILIS.CONGENITAL SYPHILIS. Affects permanent incisors and first Affects permanent incisors and first

molarsmolars Affected incisors (Hutchinson’s Affected incisors (Hutchinson’s

incisors) are tapered incisally and incisors) are tapered incisally and notched centrally on the incisal edgenotched centrally on the incisal edge

Affected molars (Mulberry molars) Affected molars (Mulberry molars) show a lobulated occlusal surface.show a lobulated occlusal surface.


FLUORIDE IONS.FLUORIDE IONS. Ingestion of drinking water containing fluoride at Ingestion of drinking water containing fluoride at

levels greater than 1 PPM during the time the levels greater than 1 PPM during the time the crowns are being formed may result in enamel crowns are being formed may result in enamel hypoplasia or hypocalcification= Fluorosis.hypoplasia or hypocalcification= Fluorosis.

Clinical features:Clinical features:Mild to moderate fluorosis:Mild to moderate fluorosis: Ranges from white enamel spots to mottled Ranges from white enamel spots to mottled

brown-and-white discolorationsbrown-and-white discolorationsSevere fluorosis:Severe fluorosis: Pitted, irregular, discolored enamelPitted, irregular, discolored enamel Are cosmetically objectionable.Are cosmetically objectionable.


AMELOGENESIS IMPERFECTA.AMELOGENESIS IMPERFECTA.Definition:Definition: It is an inherited developmental abnormality of It is an inherited developmental abnormality of

enamel. Affects both dentitions.enamel. Affects both dentitions.Classification:Classification: 2 main types 2 main types Hypoplastic: Defective matrix formationHypoplastic: Defective matrix formation Hypocalcified: Matrix formation is normal but Hypocalcified: Matrix formation is normal but

calcification is abnormalcalcification is abnormalCauses:Causes: Genetic factors Genetic factors Autosomal dominantAutosomal dominant Autosomal recessiveAutosomal recessive X-linked patternsX-linked patterns


Clinical manifestations:Clinical manifestations: The defects range from pits and grooves in one The defects range from pits and grooves in one

patient to complete absence (aplasia) in anotherpatient to complete absence (aplasia) in another Abnormal contour and absent interproximal Abnormal contour and absent interproximal

contact points may be evidentcontact points may be evident Fractures and wears due to gross attrition appear Fractures and wears due to gross attrition appear

readily in the hypocalcified type, exposing the readily in the hypocalcified type, exposing the dentinedentine

Sometimes, in the smooth form, teeth have Sometimes, in the smooth form, teeth have sharp, needle-like cuspssharp, needle-like cusps

Color varies from white opaque to yellow to Color varies from white opaque to yellow to brownbrown


Teeth tend to darken with age due to Teeth tend to darken with age due to exogenous stainingexogenous staining

The teeth are not caries proneThe teeth are not caries proneRadiographic features:Radiographic features: Enamel appears reduced in bulk, often Enamel appears reduced in bulk, often

showing a thin layer over occlusal and showing a thin layer over occlusal and interproximal surfacesinterproximal surfaces

Dentin and pulp chambers appear normalDentin and pulp chambers appear normalTreatment:Treatment: Full crown coverage for aesthetic concernsFull crown coverage for aesthetic concerns

DISTURBANCES IN DISTURBANCES IN STRUCTURE OF STRUCTURE OF

DENTINE.DENTINE.DENTINOGENESIS IMPERFECTA.DENTINOGENESIS IMPERFECTA.

Definition:Definition: Dentinogenesis imperfecta is an autosomal-dominant Dentinogenesis imperfecta is an autosomal-dominant

trait affecting the dentine, with variable expressivity. trait affecting the dentine, with variable expressivity. Affects both dentitions.Affects both dentitions.

Classification: 3 typesClassification: 3 types Type 1: Type 1: Dentin abnormality occurs in patients with concurrent Dentin abnormality occurs in patients with concurrent

osteogenesis imperfectaosteogenesis imperfecta Primary teeth more affected than permanent teethPrimary teeth more affected than permanent teeth Type 2: Only dentin abnormalities and no bone diseasesType 2: Only dentin abnormalities and no bone diseases Type 3: Similar to type 2 but with multiple pulp Type 3: Similar to type 2 but with multiple pulp

exposures, periapical radioluscencies, variable exposures, periapical radioluscencies, variable radiographic appearances.radiographic appearances.

DENTINE (cont…) DENTINE DENTINE (cont…) DENTINE (cont…)(cont…)

Clinical features:Clinical features:

In both dentitions, the teeth exhibit an unusual In both dentitions, the teeth exhibit an unusual transluscent, opalescent appearancetransluscent, opalescent appearance

Color variation from yellow-brown to gray to violetColor variation from yellow-brown to gray to violet Entire crown appears discolored because of the Entire crown appears discolored because of the

abnormal underlying dentinabnormal underlying dentin Enamel fractures easily, resulting in rapid wearEnamel fractures easily, resulting in rapid wear Overall tooth morphology unusual due to excessive Overall tooth morphology unusual due to excessive

constriction at the cemento-enamel junction, giving constriction at the cemento-enamel junction, giving the crown a tylip or bell shapethe crown a tylip or bell shape

Roots are shortened and bluntedRoots are shortened and blunted Teeth do not exhibit any greater susceptibility to Teeth do not exhibit any greater susceptibility to

cariescaries

DENTINE DEFECTS (cont…)DENTINE DEFECTS (cont…)

Radiographic features:Radiographic features:Type 1 and 2 exhibit identical features such Type 1 and 2 exhibit identical features such

as:as: Opacification of dental pulp because of Opacification of dental pulp because of

continued deposition of abnormal dentincontinued deposition of abnormal dentin Short rootsShort roots Bell-shaped crownsBell-shaped crownsType 3:Type 3: Dentin appears thinDentin appears thin Pulp chambers and root canals extremely Pulp chambers and root canals extremely

large giving the appearance of thin dentin large giving the appearance of thin dentin shells=shell teethshells=shell teeth


Histological features:Histological features: Dentin contains fewer but larger and irregular Dentin contains fewer but larger and irregular

dentinal tubulesdentinal tubules Dentin poorly calcified with occasional cellular Dentin poorly calcified with occasional cellular

inclusionsinclusions Dentin is softer and has a greater water and Dentin is softer and has a greater water and

inorganic contentinorganic content Enamel appears normalEnamel appears normal Dentino-enamel junction is smooth instead of Dentino-enamel junction is smooth instead of

scalloped.scalloped.Treatment:Treatment: Full-crown coverage (protection against tooth wear Full-crown coverage (protection against tooth wear

and aesthetic concern)and aesthetic concern)

DENTINE DEFECTS (cont…)DENTINE DEFECTS (cont…)DENTIN DYSPLASIA.DENTIN DYSPLASIA.Definition:Definition:

It is an autosomal-dominant trait that affects dentin. This It is an autosomal-dominant trait that affects dentin. This is a rare condition subdivided into type I (radicular type) is a rare condition subdivided into type I (radicular type) and a more rare type II (coronal type)and a more rare type II (coronal type)

Both dentitions are affectedBoth dentitions are affectedSimilarities with dentinogenesis imperfecta:Similarities with dentinogenesis imperfecta: Early obliteration of pulp chambers and root canals by Early obliteration of pulp chambers and root canals by

atypical dentinatypical dentinDifferencies from dentinogenesis imperfecta:Differencies from dentinogenesis imperfecta: The teeth are normal in colorThe teeth are normal in color No tendency for the enamel to chip offNo tendency for the enamel to chip off No rapid attritionNo rapid attrition Altered, retarded, deficient root formation with Altered, retarded, deficient root formation with

radioluscent areas at the apices of some teeth.radioluscent areas at the apices of some teeth.


Clinical features:Clinical features: Teeth of normal color with no attritionTeeth of normal color with no attrition Looseness, malposition, early loss of teeth due to Looseness, malposition, early loss of teeth due to

retarded root formation and lack of supporting retarded root formation and lack of supporting bonebone

Radiographic features:Radiographic features:Type I:Type I: Roots appear extremely shortRoots appear extremely short Pulps almost completely obliteratedPulps almost completely obliterated Residual fragments of pulp tissue appear typically Residual fragments of pulp tissue appear typically

as horizontal lucenciesas horizontal lucencies Periapical lucencies (chronic abscesses, Periapical lucencies (chronic abscesses,

granulomas, cysts)granulomas, cysts)

DENTINE DEFECTS (cont…)DENTINE DEFECTS (cont…)Type II:Type II:

Deciduous teeth radiographically similar to type I Deciduous teeth radiographically similar to type I Permanent teeth exhibit enlarged pulp chambers that have Permanent teeth exhibit enlarged pulp chambers that have

been described as thistle tube appearancebeen described as thistle tube appearance

Histological features:Histological features: The enamel and immediately subjacent dentin appear normalThe enamel and immediately subjacent dentin appear normal Deeper layers of dentin show atypical tubular patterns and Deeper layers of dentin show atypical tubular patterns and

irregular organizationirregular organization

Treatment:Treatment: The treatment is directed toward retention of teeth for as The treatment is directed toward retention of teeth for as

long as possiblelong as possible The prognosis is poor due to short roots and periapical The prognosis is poor due to short roots and periapical

lesions.lesions.


REGIONAL ODONTODYSPLASIA=Ghost teethREGIONAL ODONTODYSPLASIA=Ghost teeth

Definition:Definition:It is a dental abnormality that involves the hard It is a dental abnormality that involves the hard tissues derived from both the epithelial (enamel) tissues derived from both the epithelial (enamel) and mesenchymal (dentin, cementum and pulp) and mesenchymal (dentin, cementum and pulp) components of the tooth-forming apparatus.components of the tooth-forming apparatus.

Several teeth in a quadrant or region are affectedSeveral teeth in a quadrant or region are affected Both mandible and maxilla can be affectedBoth mandible and maxilla can be affected Permanent teeth more affected than deciduousPermanent teeth more affected than deciduous Maxillary anteriors mostly affectedMaxillary anteriors mostly affected

DENTINE DEFECTS (cont…)DENTINE DEFECTS (cont…) Clinical features:Clinical features:

The teeth exhibit short roots, open apical foramina and The teeth exhibit short roots, open apical foramina and enlarged pulp chambersenlarged pulp chambers

Eruption of the affected teeth is delayed or does not occurEruption of the affected teeth is delayed or does not occur Teeth have irregular shapeTeeth have irregular shape Hypoplastic and irregularly mineralized enamelHypoplastic and irregularly mineralized enamel

Radiographic features:Radiographic features:

Wide, open apicesWide, open apices Pulp stonesPulp stones Reduced radiopacity of the teethReduced radiopacity of the teeth Loss of distinction between the enamel and dentine Loss of distinction between the enamel and dentine

described as a “ghostly” appearance.described as a “ghostly” appearance.

DISTURBANCES IN DISTURBANCES IN STRUCTURE OF STRUCTURE OF

CEMENTUM.CEMENTUM. The coronal 1/3 of the cement consists The coronal 1/3 of the cement consists

of acellular cementum (primary) of acellular cementum (primary) whereas the apical 2/3 consists of whereas the apical 2/3 consists of cellular cementum (secondary).cellular cementum (secondary).

The cellular cementum continues to be The cellular cementum continues to be formed throughout the life of the tooth.formed throughout the life of the tooth.

Thickness varies between individuals, Thickness varies between individuals, generally increases with age to generally increases with age to compensate for occlusal wear.compensate for occlusal wear.

CEMENTUM DEFECTS CEMENTUM DEFECTS (cont…)(cont…)

HYPERCEMENTOSIS.HYPERCEMENTOSIS.Definition:Definition: This is an abnormally increased cementogenesisThis is an abnormally increased cementogenesisAetiology:Aetiology: Some cases are idiopathicSome cases are idiopathic Others may be associated with certain conditions like:Others may be associated with certain conditions like: Periapical inflammation (generalized thickening or Periapical inflammation (generalized thickening or

localized knob-like enlargement)localized knob-like enlargement) Mechanical stimulationMechanical stimulation Functionless and unerupted teethFunctionless and unerupted teeth Paget’s disease of bonePaget’s disease of bone Hypercementosis may be associated with root ankylosisHypercementosis may be associated with root ankylosisSignificance: The tooth extraction can be laboriousSignificance: The tooth extraction can be laborious

CEMENTUM DEFECTS CEMENTUM DEFECTS (cont…)(cont…)

HYPOCEMENTOSIS.HYPOCEMENTOSIS.Hypoplasia and aplasia of cementum are uncommonHypoplasia and aplasia of cementum are uncommonHypocementum is associated with:Hypocementum is associated with:

Cleidocranial dysplasia in which there is lack of cellular Cleidocranial dysplasia in which there is lack of cellular cementumcementum

Hypophosphatasia characterized by: Reduced serum Hypophosphatasia characterized by: Reduced serum alkaline phosphatase level, Deformities of extremities alkaline phosphatase level, Deformities of extremities similar to those of rickets, Failure of calcification of the similar to those of rickets, Failure of calcification of the calvariumcalvarium

Clinical complications:Clinical complications: Premature loss of some or all deciduous and permanent Premature loss of some or all deciduous and permanent

teeth due to poor periodontal attachment and abnormal teeth due to poor periodontal attachment and abnormal dentine formation.dentine formation.

DISTURBANCES IN DISTURBANCES IN STRUCTURE OF THE STRUCTURE OF THE

PULP.PULP.PULP CALCIFICATION.PULP CALCIFICATION.

It is a common phenomenon that occurs with increasing age for no It is a common phenomenon that occurs with increasing age for no apparent reasonapparent reason

There appears to be no relation to inflammation, trauma or There appears to be no relation to inflammation, trauma or systemic diseasesystemic disease

May be of microscopic size or large enough to be detected May be of microscopic size or large enough to be detected radiographicallyradiographically

Calcifications may be diffuse (linear) or nodular (pulp stones)Calcifications may be diffuse (linear) or nodular (pulp stones) Linear calcifications are typically found in root canals, pulp stones Linear calcifications are typically found in root canals, pulp stones

in pulp chambersin pulp chambers Can be true denticles when composed predominantly by dentin or Can be true denticles when composed predominantly by dentin or

false denticles when they represent foci of dystrophic false denticles when they represent foci of dystrophic calcificationscalcifications

Are referred to as attached pulp stones when incorporated into Are referred to as attached pulp stones when incorporated into dentine or free pulp stones when surrounded by pulpal tissue dentine or free pulp stones when surrounded by pulpal tissue

Clinical significance:Clinical significance: None but can be problematic during endodontic therapy None but can be problematic during endodontic therapy

OTHER DISORDERS OF TEETHOTHER DISORDERS OF TEETH

DISORDERS OF ERUPTION DISORDERS OF ERUPTION AND SHEDDING OF AND SHEDDING OF

TEETH.TEETH.1.1. PREMATURE ERUPTION, NATAL AND NEONATAL PREMATURE ERUPTION, NATAL AND NEONATAL

TEETH.TEETH.

Natal teeth are slightly more common than neonatal teethNatal teeth are slightly more common than neonatal teeth They are seen in +/- 1 in 3000 live birthsThey are seen in +/- 1 in 3000 live births Almost always one or two central incisors are involvedAlmost always one or two central incisors are involved The mandible is four time more involved than the maxillaThe mandible is four time more involved than the maxillaAetiology:Aetiology: Normal tooth germ developing in a superficial position in a Normal tooth germ developing in a superficial position in a

superficial position in the jawsuperficial position in the jawPrognosis:Prognosis: They are either lost spontaneouslyThey are either lost spontaneously Can be extracted to prevent them being inhaled or ulcerate Can be extracted to prevent them being inhaled or ulcerate

the tongue or the mother’s nipplethe tongue or the mother’s nipple If left in the jaw, the roots may sometimes continue to If left in the jaw, the roots may sometimes continue to

develop and the teeth become firm.develop and the teeth become firm.

ERUPTION AND SHEDDING ERUPTION AND SHEDDING (cont…)(cont…)

2.RETARDED ERUPTION.2.RETARDED ERUPTION.Can be associated with:Can be associated with: Endocrinopathies (e.g. hypothyroidism)Endocrinopathies (e.g. hypothyroidism) PrematurityPrematurity Nutritional deficienciesNutritional deficiencies Down’s syndromeDown’s syndromeBoth dentitions can be affectedBoth dentitions can be affectedOther causes involved:Other causes involved: Idiopathic migrationIdiopathic migration Traumatic displacement of tooth germsTraumatic displacement of tooth germs Abnormally large crownsAbnormally large crowns Cleidocranial dysplasia causing delayed eruption and Cleidocranial dysplasia causing delayed eruption and multiple and impacted supernumerary teeth.multiple and impacted supernumerary teeth.


3.PREMATURE LOSS.3.PREMATURE LOSS.

Usually it is the result of either dental caries and its Usually it is the result of either dental caries and its sequelae or chronic periodontal diseasesequelae or chronic periodontal disease

Occasionally associated with:-HypophasphatasiaOccasionally associated with:-Hypophasphatasia -Prepubertal periodontitis-Prepubertal periodontitis -Hereditary palmar-plantar -Hereditary palmar-plantar

hyperkeratosishyperkeratosis

4.PERSISTANCE OF DECIDUOUS TEETH.4.PERSISTANCE OF DECIDUOUS TEETH. Usually associated with the failure of eruption of the Usually associated with the failure of eruption of the

permanent successorspermanent successors Persistance of the entire deciduous dentition is uncommon Persistance of the entire deciduous dentition is uncommon ( cleidocranial dysplasia when eruption of permanent teeth is ( cleidocranial dysplasia when eruption of permanent teeth is

impeded)impeded)


5. IMPACTION OF TEETH.5. IMPACTION OF TEETH.Definition:Definition:

An impacted tooth is one which remains An impacted tooth is one which remains unerupted or only partly erupted, in the jaw unerupted or only partly erupted, in the jaw beyond the time it should normally be fully beyond the time it should normally be fully erupted.erupted.

One or several teeth may be affectedOne or several teeth may be affected The condition may be symmetricalThe condition may be symmetrical Rarely seen in primary dentitionRarely seen in primary dentitionTeeth most frequently involved are:Teeth most frequently involved are: Third molarsThird molars Mandibular premolarsMandibular premolars Maxillary caninesMaxillary canines


Aetiology:Aetiology:

Local factors:Local factors: Abnormal position of the tooth germAbnormal position of the tooth germ Lack of space for the teethLack of space for the teeth Supernumerary teethSupernumerary teeth Cysts and tumoursCysts and tumours

Systemic factorsSystemic factors: Cleidocranial dysplasia (multiple impacted : Cleidocranial dysplasia (multiple impacted teeth)teeth)

Possible complications:Possible complications:

Resorption of the impacted tooth or adjacent erupted teethResorption of the impacted tooth or adjacent erupted teeth Development of dentigerous cysts and odontogenic Development of dentigerous cysts and odontogenic

tumours tumours


REIMPACTION OF TEETH (Infraocclusion, REIMPACTION OF TEETH (Infraocclusion, Submerged teeth).Submerged teeth).

Definition:Definition: It is a situation in which previously erupted tooth It is a situation in which previously erupted tooth becomes submerged in the tissues.becomes submerged in the tissues.

The deciduous second molar most commonly The deciduous second molar most commonly affectedaffected

Mandible two times more affected than maxillaMandible two times more affected than maxillaClinical features.Clinical features. Deficient development of the alveolar process Deficient development of the alveolar process

around the reimpacted tooth which may become around the reimpacted tooth which may become completely covered by oral mucosacompletely covered by oral mucosa

The roots are usually partly resorbed and The roots are usually partly resorbed and ankylosed to the bone.ankylosed to the bone.

NON-BACTERIAL NON-BACTERIAL LOSS OF TOOTH STRUCTURE.LOSS OF TOOTH STRUCTURE.

TOOTH WEARTOOTH WEAR

ATTRITION.ATTRITION.Definition:Definition:

This is a loss of tooth substance as a result of This is a loss of tooth substance as a result of tooth-to-tooth contact. It is an age-related tooth-to-tooth contact. It is an age-related process and varies from one individual to process and varies from one individual to another.another.

It may be physiological or pathological in originIt may be physiological or pathological in originChronology:Chronology: Incisal edges of the incisors are worn firstIncisal edges of the incisors are worn first Occlusal surfaces of the molarsOcclusal surfaces of the molars Palatal cusps of the maxillary teeth and buccal Palatal cusps of the maxillary teeth and buccal

cusps of mandibular teeth.cusps of mandibular teeth.

TOOTH WEAR (cont…)TOOTH WEAR (cont…) When the dentine becomes exposed, it generally When the dentine becomes exposed, it generally

becomes discoloured brown.becomes discoloured brown. The patient may complain of hypersensitive The patient may complain of hypersensitive

dentine.dentine. Men generally show more severe attrition than Men generally show more severe attrition than

womenwomenAetiology:Aetiology: Abnormal occlusionAbnormal occlusion Bruxism and habits such as tobacco and betel Bruxism and habits such as tobacco and betel

chewingchewing Abnormal tooth structureAbnormal tooth structure Abrasive property of foodAbrasive property of food

TOOTH WEAR (cont…)TOOTH WEAR (cont…)

ABRASION.ABRASION. Definition:Definition: It is a pathological wearing away of tooth It is a pathological wearing away of tooth

substance as a result of an abnormal use substance as a result of an abnormal use of abrasive substances orally or abnormal of abrasive substances orally or abnormal use of abrasive substances orally.use of abrasive substances orally.

-The location and pattern are directly -The location and pattern are directly dependaent on the causedependaent on the cause

-The gingival 1/3, incisal edges and -The gingival 1/3, incisal edges and proximal surfaces are more affectedproximal surfaces are more affected


Aetiology:Aetiology: Tooth brush abrasion (left side more Tooth brush abrasion (left side more

involved in righthanded and vice versa)involved in righthanded and vice versa) Pipe smokingPipe smoking Chewing tobacco and various foreign Chewing tobacco and various foreign

substances (sand, stones)substances (sand, stones) Use of abrasive dentifriceUse of abrasive dentifrice Occupational abrasion( holding objects Occupational abrasion( holding objects

between or against teeth during work like between or against teeth during work like thread or nails)thread or nails)

Ritual abrasionRitual abrasion


EROSION.EROSION.Definition:Definition: This is loss of tooth structure from a This is loss of tooth structure from a

non-bacterial chemical processnon-bacterial chemical processAetiology:Aetiology: External or internal acids such as: External or internal acids such as: Excessive intake of acidic beveragesExcessive intake of acidic beverages Sucking citrus fruits (lemons)Sucking citrus fruits (lemons) Occupational erosion (e.g. battery Occupational erosion (e.g. battery

manufacturing)manufacturing) Chronic alcoholismChronic alcoholism Idiopathic erosion (acidic saliva)Idiopathic erosion (acidic saliva) The patient may complain of hypersensitive The patient may complain of hypersensitive

dentine.dentine.


Resorption.Resorption. It can be physiological like the resorption of It can be physiological like the resorption of

deciduous teeth or microscopic areas of deciduous teeth or microscopic areas of superficial resorption of the roots of permanent superficial resorption of the roots of permanent teeth.teeth.

When the resorption is sufficient to be When the resorption is sufficient to be diagnosed radiologically it is always diagnosed radiologically it is always pathologicalpathological

It is not a continuous process, osteoclasts are It is not a continuous process, osteoclasts are not always present.not always present.

There are 2 types: External resorption and There are 2 types: External resorption and internal resorptioninternal resorption

TOOTH WEAR (cont…)TOOTH WEAR (cont…) Pathological external resorption may be Pathological external resorption may be

associated with:associated with: Periapical inflammationPeriapical inflammation Mechanical stimulation (excessive force in Mechanical stimulation (excessive force in

orthodontic treatment)orthodontic treatment) Neoplasms or cystsNeoplasms or cysts Unerupted teethUnerupted teeth Transplanted or replanted teetTransplanted or replanted teet Idiopathic resorptionIdiopathic resorption Pathological internal resorption is usually Pathological internal resorption is usually

associated with pulpitis. associated with pulpitis.

DISCOLORATION OF TEETH.DISCOLORATION OF TEETH.

Normal variation in the color of teeth must Normal variation in the color of teeth must be distinguished from pathological be distinguished from pathological

discoloration.discoloration.Aetiology:Aetiology: Surface deposits (Extrinsic stains)Surface deposits (Extrinsic stains) Changes in the structure or thickness of Changes in the structure or thickness of

the dental hard tissuesthe dental hard tissues Diffusion of pigments into the dental hard Diffusion of pigments into the dental hard

tissues after their formationtissues after their formation Incorporation of pigments into the dental Incorporation of pigments into the dental

hard tissues during their formationhard tissues during their formation

DISCOLORATION OF TEETH DISCOLORATION OF TEETH (cont…).(cont…).

Extrinsic stains:Extrinsic stains: Substances in the dietSubstances in the diet Habitual chewing of betel nut or Habitual chewing of betel nut or

tobaccotobacco Tobacco smokingTobacco smoking MedicationsMedications Chromogenic bacteriaChromogenic bacteria


Changes in the structure or thickness Changes in the structure or thickness of of

dental tissuesdental tissues

Enamel hypoplasia, fluorosisEnamel hypoplasia, fluorosis Amelogenesis imperfectaAmelogenesis imperfecta Enamel opacitiesEnamel opacities Enamel cariesEnamel caries Dentinogenesis imperfectaDentinogenesis imperfecta Dentinal dysplasia type IIDentinal dysplasia type II Age changes in dental tisúesAge changes in dental tisúes


DIFFUSION OF PIGMENTS INTO DENTAL TISSÚES AFTER DIFFUSION OF PIGMENTS INTO DENTAL TISSÚES AFTER THEIR FORMATION.THEIR FORMATION.

Extrinsic stainsExtrinsic stains Endodontic materialsEndodontic materials Products of pulp necrosis (Lysis of necrotic tissue and red Products of pulp necrosis (Lysis of necrotic tissue and red

blood cells)blood cells)

PIGMENTS INCORPORATED DURING FORMATION OF PIGMENTS INCORPORATED DURING FORMATION OF DENTAL TISSUES.DENTAL TISSUES. Bile pigments (Rhesus incompatibility); the color appears Bile pigments (Rhesus incompatibility); the color appears

yellowish-brownyellowish-brown Porphyrins; the color appears pinkish-brownPorphyrins; the color appears pinkish-brown Tetracyclins; the color appears yellowish at eruption then Tetracyclins; the color appears yellowish at eruption then

darker and brownerdarker and browner

REIMPLANTATION OF REIMPLANTATION OF TEETH.TEETH.

Definition:Definition:It is an avulsed tooth following traumatism It is an avulsed tooth following traumatism that is returned to its own socket.that is returned to its own socket.

Clinical features:Clinical features: Usually, the pulp and soft tissues attached to Usually, the pulp and soft tissues attached to

the root degenerate due to traumatic injury of the root degenerate due to traumatic injury of the blood supplythe blood supply

Sometimes the resorption is rapid but other Sometimes the resorption is rapid but other times it is slowly progressive up to 10-15 yearstimes it is slowly progressive up to 10-15 years

Resorption is largely a function of the length of Resorption is largely a function of the length of time the tooth has been out of the jaw.time the tooth has been out of the jaw.

ROOT FRACTURE.ROOT FRACTURE.

The outcome of an intra-alveolar The outcome of an intra-alveolar fracture of a root depends on:fracture of a root depends on:

Presence or absence of infectionPresence or absence of infection The vitality of the pulpThe vitality of the pulp The position of the fragmentsThe position of the fragments The degree of communitionThe degree of communition The location of the fractureThe location of the fracture The mobility of the coronal The mobility of the coronal

fragmentfragment

ROOT FRACTURE ROOT FRACTURE (cont…).(cont…).

Healing processHealing process: It may occur in 3 patterns: It may occur in 3 patterns The roots fragments become united totally, or in part, The roots fragments become united totally, or in part,

by calcified repair tissue resembling bone and/or by calcified repair tissue resembling bone and/or cementumcementum

The fractured surfaces of each fragment become The fractured surfaces of each fragment become rounded off and clothed by cementum but are not rounded off and clothed by cementum but are not united by calcified tissue. Fibrous tissue fills the space.united by calcified tissue. Fibrous tissue fills the space.

The fractured surfaces of each fragment become The fractured surfaces of each fragment become rounded off and clothed by cementum but the rounded off and clothed by cementum but the fragments are widely separated. Alveolar bone fills the fragments are widely separated. Alveolar bone fills the space.space.

The pulp chamber in either fragment may The pulp chamber in either fragment may become obliterated by calcified tissue.become obliterated by calcified tissue.

AGE CHANGES IN TEETH.AGE CHANGES IN TEETH.

These include changes in morphology associated with tooth wear These include changes in morphology associated with tooth wear especially attrition and changes in structure and composition especially attrition and changes in structure and composition of the dental hard tissues.of the dental hard tissues.

Enamel.Enamel. Tends to become more brittle and less permeable (ionic Tends to become more brittle and less permeable (ionic

exchange)exchange) It darken with age (absorption of organic material)It darken with age (absorption of organic material)Dentine.Dentine. Continued formation of secondary dentine leading to Continued formation of secondary dentine leading to

reduction in size or obliteration of the pulp chamber.reduction in size or obliteration of the pulp chamber. Dentinal sclerosis associated with continued production of Dentinal sclerosis associated with continued production of

peritubular dentine resulting in root brittleness that may peritubular dentine resulting in root brittleness that may fracture during extractionfracture during extraction

The dentinal sclerosis is also associated with increasing The dentinal sclerosis is also associated with increasing translucency that can be used in forensic dentistry as one translucency that can be used in forensic dentistry as one method of age estimation.method of age estimation.

AGE CHANGES (cont…)AGE CHANGES (cont…)

Cementum.Cementum. Gradual increase in thickness to compensate for Gradual increase in thickness to compensate for

interproximal and occlusal attritioninterproximal and occlusal attrition The amount of secondary cementum can also The amount of secondary cementum can also

be used for age estimationbe used for age estimationPulp.Pulp. The volume gradually decreases due to The volume gradually decreases due to

continued production of secondary dentinecontinued production of secondary dentine Decreased vascularity, reduction in cellularity Decreased vascularity, reduction in cellularity

and increase in collagen fibres may impair the and increase in collagen fibres may impair the response to injury and its healing potential.response to injury and its healing potential.

Prevalence of pulp stones and diffuse Prevalence of pulp stones and diffuse calcification increase.calcification increase.

ODONTOMAS AND ODONTOGENIC ODONTOMAS AND ODONTOGENIC TUMOURS.TUMOURS.

A. ODONTOMAS.A. ODONTOMAS.

Definition:Definition:It is a non-neoplastic, developmental anomally or It is a non-neoplastic, developmental anomally or malformation that contains fully formed enamel malformation that contains fully formed enamel and dentine. It can be considered as dental and dentine. It can be considered as dental hamartomas containing the calcified dental hamartomas containing the calcified dental tissues. Are the most common odontogenic tissues. Are the most common odontogenic tumours.tumours.

There are 2 types:There are 2 types: Compound odontomas: Numerous miniature or Compound odontomas: Numerous miniature or

rudimentary teethrudimentary teeth Complex odontomas: Amorphous Complex odontomas: Amorphous

conglomerations of hard tissuesconglomerations of hard tissues

ODONTOMAS (cont…).ODONTOMAS (cont…).

Clinical features:Clinical features: Lesions of children and young adults (2nd decade Lesions of children and young adults (2nd decade

of life)of life) Maxilla affected slightly more often than Maxilla affected slightly more often than

mandiblemandible Compound odontomas have a tendency to occur Compound odontomas have a tendency to occur

in the anterior jawsin the anterior jaws Complex odontomas in the posterior jawsComplex odontomas in the posterior jaws No gender predilectionNo gender predilection Associated with a retained deciduous tooth, an Associated with a retained deciduous tooth, an

impacted tooth and alveolar swellingimpacted tooth and alveolar swelling Generally no symptoms.Generally no symptoms.

ODONTOMAS (cont…). ODONTOMAS (cont…).

Radiographic features:Radiographic features:1.Compound odontomas:1.Compound odontomas: Appear as numerous tiny teeth in a single focusAppear as numerous tiny teeth in a single focus The focus is typically in a tooth-bearing area, The focus is typically in a tooth-bearing area,

between roots or over the crown of an impacted between roots or over the crown of an impacted toothtooth

As many as 200 such structures have been As many as 200 such structures have been observed in a single lesionobserved in a single lesion

2.Complex odontomas:2.Complex odontomas: Appear in the same regions but as amorphous, Appear in the same regions but as amorphous,

opaque mass.opaque mass.

ODONTOMAS (cont…).ODONTOMAS (cont…).Histological features:Histological features: Normal-appearing enamel, dentin, cementum, and pulp Normal-appearing enamel, dentin, cementum, and pulp

may be seen in these lesionsmay be seen in these lesions Prominent enamel matrix and the associated enamel organ Prominent enamel matrix and the associated enamel organ

are often seen before final maturation of hard tissue.are often seen before final maturation of hard tissue.Differential diagnosis:Differential diagnosis: Other opaque jaw lesions such as: -Focal sclerosing osteitisOther opaque jaw lesions such as: -Focal sclerosing osteitis

-Osteoma-Osteoma -Periapical cemental dysplasia-Periapical cemental dysplasia

-Ossifying fibroma-Ossifying fibroma -Cementoblastoma-Cementoblastoma Usually compound odontomas are self-diagnostic and Usually compound odontomas are self-diagnostic and

complex odontomas present a solid opacification in complex odontomas present a solid opacification in relationship to teeth.relationship to teeth.

B. ODONTOGENIC B. ODONTOGENIC TUMOURS.TUMOURS.

Odontogenic tumours are lesions derived from Odontogenic tumours are lesions derived from the epithelial and/or mesenchymal remnants of the epithelial and/or mesenchymal remnants of the tooth-forming apparatus.the tooth-forming apparatus.

Are therefore found exclusively in the mandible Are therefore found exclusively in the mandible and the maxillaand the maxilla

The etiology and pathogenesis are unknownThe etiology and pathogenesis are unknown Clinically asymptomatic but may cause jaw Clinically asymptomatic but may cause jaw

expansion, movement of teeth, root resorption expansion, movement of teeth, root resorption and bone loss.and bone loss.

Differential diagnosis can be based on age, Differential diagnosis can be based on age, location, radiographic appearance location, radiographic appearance

Range from benign to malignant tumors.Range from benign to malignant tumors.

ODONTOGENIC TUMOURS ODONTOGENIC TUMOURS (cont…)(cont…)

EPITHELIAL TUMOURS.EPITHELIAL TUMOURS.AMELOBLASTOMA.AMELOBLASTOMA.Definition:Definition:

This is a benign but locally invasive This is a benign but locally invasive neoplasm derived from odontogenic neoplasm derived from odontogenic epithelium. It is the commonest of the epithelium. It is the commonest of the odontogenic tumours.odontogenic tumours.

Accounts for approximately 1% of all oral Accounts for approximately 1% of all oral tumourstumours

-More common in black Americans and -More common in black Americans and West Africans (6% or more of oral tumours)West Africans (6% or more of oral tumours)

AMELOBLASTOMA(cont…AMELOBLASTOMA(cont…))

Clinical features:Clinical features: Can occur in children or the elderly butCan occur in children or the elderly but In industrialized countries, usually in fourth or fifth In industrialized countries, usually in fourth or fifth

decades of lifedecades of life In developing countries, about 10-15 years earlierIn developing countries, about 10-15 years earlier About 80% occur in the mandible of which 70% About 80% occur in the mandible of which 70%

arise in molar region and ascending ramus, 20% in arise in molar region and ascending ramus, 20% in the premolar region and 10% in the incisor region.the premolar region and 10% in the incisor region.

In the maxilla, most also occur in the molar region, In the maxilla, most also occur in the molar region, 15% involving the antrum15% involving the antrum

The tumour is slow-growing but locally invasiveThe tumour is slow-growing but locally invasive It is asymptomatic in early stages and can be It is asymptomatic in early stages and can be

discovered as an incidental findingdiscovered as an incidental finding


As the tumour enlarges, there is facial deformity As the tumour enlarges, there is facial deformity and expansion of the jaw boneand expansion of the jaw bone

The enlargement is initially bony hard, non-The enlargement is initially bony hard, non-tender, ovoid or fusiform in outlinetender, ovoid or fusiform in outline

In advanced cases, egg-shell crackling may be In advanced cases, egg-shell crackling may be elicited due to thinning of the overlying boneelicited due to thinning of the overlying bone

In late features, there is perforation of bone and In late features, there is perforation of bone and extension of the tumour into soft tissues. In extension of the tumour into soft tissues. In maxilla, it can expand into the sinus and beyondmaxilla, it can expand into the sinus and beyond

Teeth may become loosened, pain is rarely a Teeth may become loosened, pain is rarely a featurefeature

In rare cases, pulmonary metastases may occurIn rare cases, pulmonary metastases may occur


Malignant variants of ameloblastoma may Malignant variants of ameloblastoma may rarely be encountered:rarely be encountered:

-Malignant ameloblastomas: well -Malignant ameloblastomas: well differentiateddifferentiated

-Ameloblastic carcinomas: less microscopic -Ameloblastic carcinomas: less microscopic differentiation with cytologic atypia and differentiation with cytologic atypia and mitotic figures.mitotic figures.

Metastases appear usually in the lung, Metastases appear usually in the lung, followed by regional lymphnodes, the followed by regional lymphnodes, the skull, liver, spleen, kidney and skin.skull, liver, spleen, kidney and skin.


Radiographic features:Radiographic features: Appears most commonly as a multilocular Appears most commonly as a multilocular

radiolucency but may also be unilocularradiolucency but may also be unilocular Roots of teeth involved show varying Roots of teeth involved show varying

degrees of resorptiondegrees of resorption The margins are well defined and scleroticThe margins are well defined and sclerotic May become associated with an unerupted May become associated with an unerupted

tooth, particularly an impacted third molar tooth, particularly an impacted third molar and mimic the appearance of a and mimic the appearance of a dentigerous cystdentigerous cyst

At an early stage, can be mistaken for an At an early stage, can be mistaken for an odontogenic cystodontogenic cyst


Histological features:Histological features: There are 2 types: The follicular and the plexiform patterns.There are 2 types: The follicular and the plexiform patterns.

a.Follicular pattern:a.Follicular pattern: The tumour epithelium is arranged into more or less The tumour epithelium is arranged into more or less

discrete, round islands or follicles, resembling the enamel discrete, round islands or follicles, resembling the enamel organ of the developing tooth germorgan of the developing tooth germ

The follicles consist of a central mass of loosely connected, The follicles consist of a central mass of loosely connected, angular cells resembling the stellate reticulum of the angular cells resembling the stellate reticulum of the normal enamel organ, surrounded by a layer of cuboidal or normal enamel organ, surrounded by a layer of cuboidal or columnar cells resembling ameloblastscolumnar cells resembling ameloblasts

The nuclei are stimulated away from the basal ends of the The nuclei are stimulated away from the basal ends of the cells= reversed polaritycells= reversed polarity

The follicles are separated by varying amounts of fibrous The follicles are separated by varying amounts of fibrous connective tissueconnective tissue


Microcyst formation is common that may coalesce to form Microcyst formation is common that may coalesce to form larger areas of cystic change within the tumourlarger areas of cystic change within the tumour

Sometimes, small areas of squamous metaplasia may occur Sometimes, small areas of squamous metaplasia may occur and then the tumour is called acanthomatous and then the tumour is called acanthomatous ameloblastomaameloblastoma

b.Plexiform pattern:b.Plexiform pattern:

The tumour epithelium is arranged as a tangled network of The tumour epithelium is arranged as a tangled network of anastomosing strands and irregular masses each of which anastomosing strands and irregular masses each of which shows the same cell layers as for foliicular patternshows the same cell layers as for foliicular pattern

Each strand or mass is bounded by columnar or cuboidal Each strand or mass is bounded by columnar or cuboidal cells resembling ameloblastscells resembling ameloblasts

The central area is occupied by stellate reticulum-like cellsThe central area is occupied by stellate reticulum-like cells Cystic formation is common, caused by stromal Cystic formation is common, caused by stromal

degeneration degeneration


Pathogenesis:Pathogenesis: Originates within the mandible or maxilla from Originates within the mandible or maxilla from

epithelium involved in the formation of teeth epithelium involved in the formation of teeth Potential epithelial sources: Potential epithelial sources: - Enamel organ- Enamel organ-Odontogenic rests (rests of Mallassez, rests of Serres)-Odontogenic rests (rests of Mallassez, rests of Serres)-Reduced enamel epithelium-Reduced enamel epithelium-Epithelial lining of odontogenic cysts (e.g. -Epithelial lining of odontogenic cysts (e.g.

dentigerous cyst)dentigerous cyst)-Basal layer of oral epithelium-Basal layer of oral epithelium The trigger for neoplastic transformation totally The trigger for neoplastic transformation totally

unknown unknown


Differential diagnosis:Differential diagnosis: Odontogenic tumours (calcifying epithelial Odontogenic tumours (calcifying epithelial

odontogenic tumour)odontogenic tumour) Odontogenic cysts (dentigerous cyst, odontogenic Odontogenic cysts (dentigerous cyst, odontogenic

keratcyst)keratcyst) Benign non-odontogenic lesions (central giant cell Benign non-odontogenic lesions (central giant cell

granuloma, ossifying fibroma)granuloma, ossifying fibroma)Management:Management: Surgical resection with a margin of normal boneSurgical resection with a margin of normal bone Simple curettage is associated with high Simple curettage is associated with high

recurrence rate (50-90%)recurrence rate (50-90%) Good follow-up since recurrence can appear 10-Good follow-up since recurrence can appear 10-

20 years later.20 years later.

ODONTOGENIC MYXOMA.ODONTOGENIC MYXOMA.

Definition:Definition: This is a benign but locally invasive and This is a benign but locally invasive and aggressive neoplasm. It is a mesenchymal aggressive neoplasm. It is a mesenchymal lesion that mimics microscopically the lesion that mimics microscopically the dental pulp or follicular connective tissue.dental pulp or follicular connective tissue.

Clinical features:Clinical features: -Age extends from 10 to 50 years with a -Age extends from 10 to 50 years with a

mean of about 30 yearsmean of about 30 years -No gender predilection-No gender predilection -Mandible and maxilla equally affected-Mandible and maxilla equally affected

ODONTOGENIC MYXOMA ODONTOGENIC MYXOMA (cont…)(cont…)

Radiographic features:Radiographic features: The lesion is always lucent, the pattern may be variableThe lesion is always lucent, the pattern may be variable May appear as a well –circumscribed or a diffuse lesionMay appear as a well –circumscribed or a diffuse lesion Often multilocular and has a honey-comb or a soap-bubble Often multilocular and has a honey-comb or a soap-bubble

appearancesappearances Cortical expansion or perforation and root displacement or Cortical expansion or perforation and root displacement or

resorption may be seenresorption may be seenHistologic features:Histologic features: Stellate, fibroblast-like cells with long anastomosing Stellate, fibroblast-like cells with long anastomosing

processes, separated by abundant connective processes, separated by abundant connective tissue=glucosaminoglucanstissue=glucosaminoglucans

Some cases contain a few strands of odontogenic epitheliumSome cases contain a few strands of odontogenic epithelium Variant amount of collagen may be present making it Variant amount of collagen may be present making it

difficult to distinguish between myxoid change in a fibroma difficult to distinguish between myxoid change in a fibroma and fibrous change in a myxoma hence the terms and fibrous change in a myxoma hence the terms myxofibroma and fibromyxoma.myxofibroma and fibromyxoma.

ODONTOGENIC MYXOMA ODONTOGENIC MYXOMA (cont…)(cont…)

Differential diagnosis:Differential diagnosis: Same as for ameloblastomaSame as for ameloblastoma

Management:Management: Surgical excision for complete Surgical excision for complete

removal but the locally invasive removal but the locally invasive growth makes it difficult and growth makes it difficult and predisposes to local recurrencepredisposes to local recurrence

Prognosis is good.Prognosis is good.

CEMENTOBLASTOMA.CEMENTOBLASTOMA.

CEMENTOBLASTOMA.CEMENTOBLASTOMA.Definition:Definition: It is also known as true cementoma and it is a rare benign It is also known as true cementoma and it is a rare benign

neoplasm of cementoblast origin.neoplasm of cementoblast origin.Clinical features:Clinical features: Occurs predominantly in the 2nd and 3rd decades of life, Occurs predominantly in the 2nd and 3rd decades of life,

typically before 25 years of agetypically before 25 years of age No gender predilectionNo gender predilection Mandible more affected than maxillaMandible more affected than maxilla Posterior region more involved than anteriorPosterior region more involved than anterior Intimately associated with the root of a toothIntimately associated with the root of a tooth The tooth involved is vitalThe tooth involved is vital It is slowly enlargingIt is slowly enlarging May cause cortical expansion and occasionally low-grade May cause cortical expansion and occasionally low-grade

intermittent pain.intermittent pain.

CEMENTOBLASTOMA CEMENTOBLASTOMA (cont…).(cont…).

Radiographic features:Radiographic features: Opaque lesion replacing the root of the toothOpaque lesion replacing the root of the tooth Usually surrounded by a radiolucent ring Usually surrounded by a radiolucent ring

representing the periodontal ligament space representing the periodontal ligament space and the advancing front of the tumourand the advancing front of the tumour

The root usually shows resorptionThe root usually shows resorptionHistologic features:Histologic features: Appears as a dense mass of mineralized Appears as a dense mass of mineralized

cementum-like materialcementum-like material Intervening well-vascularized soft issue Intervening well-vascularized soft issue

containing numerous, large and hyperchromatic containing numerous, large and hyperchromatic cementoblastscementoblasts

CEMENTOBLASTOMA CEMENTOBLASTOMA (cont…).(cont…).

Differential diagnosis:Differential diagnosis: OdontomasOdontomas OsteoblastomasOsteoblastomas Focal sclerosing osteomyelitisFocal sclerosing osteomyelitis HypercementosisHypercementosisTreatment:Treatment: Surgical excision for complete removalSurgical excision for complete removal Sacrifice the tooth because of the intimate Sacrifice the tooth because of the intimate

association between the root and the association between the root and the tumourtumour

Prognosis:Prognosis: Good, recurrence not seen Good, recurrence not seen

OTHER ODONTOGENIC OTHER ODONTOGENIC TUMOURSTUMOURS

Epithelial tumours:Epithelial tumours:

-Calcifying epithelial odontogenic -Calcifying epithelial odontogenic tumourtumour

-Adenomatoid odontogenic tumour-Adenomatoid odontogenic tumour

-Squamous odontogenic tumour-Squamous odontogenic tumour

-Clear cell odontogenic tumour-Clear cell odontogenic tumour

Mesenchymal tumours:Mesenchymal tumours:

-Central odontogenic fibroma-Central odontogenic fibroma

-Cementifying fibroma-Cementifying fibroma

-Periapical cementoosseous dysplasia-Periapical cementoosseous dysplasia

Mixed tumoursMixed tumours (epithelial and (epithelial and mesenchymal): mesenchymal):

-Ameloblastic fibroma and -Ameloblastic fibroma and Ameloblastic Ameloblastic fibroodontomafibroodontoma

ReferencesReferences

Hamilton B.G.Robinson, Arthur S.Miller (1993), Colby, Kerr and Robinson’s Hamilton B.G.Robinson, Arthur S.Miller (1993), Colby, Kerr and Robinson’s Color Atlas of Oral Pathology, 4Color Atlas of Oral Pathology, 4thth edition, edition, J.B. Lippincott CompanyJ.B. Lippincott Company, pp.35-, pp.35-50;53-67;146-15150;53-67;146-151

Joseph A.Regezi, DDS,MS; James J.Sciubba, DMD,PHD; Richard Joseph A.Regezi, DDS,MS; James J.Sciubba, DMD,PHD; Richard C,K,Jordan, DDS, Msc, Phd, FRCD (C) (1999),Oral Pathology, 4C,K,Jordan, DDS, Msc, Phd, FRCD (C) (1999),Oral Pathology, 4 thth Edition, Edition, Saunders, Saunders, pp 267-288; 367-384pp 267-288; 367-384

Soames J.V. and Southan J.C. (1999), Oral Pathology, Third Edition, Soames J.V. and Southan J.C. (1999), Oral Pathology, Third Edition, Oxford, Oxford, pp 1-17; 37-48; 59;267-285pp 1-17; 37-48; 59;267-285

disorders of development of teeth. may be prenatal or postnatal in origin may be prenatal or...

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