developmental disturbances of teeth

DEVELOPMENTAL DISTURBANCES OF TEETH

Presented by Melbia shinyFirst MDS

contents

Classification Clinical features Radiological features Treatment

Development of tooth

amelogenesis

Formation of enamel matrix Mineralisation of matrix Maturation of enamel

dentinogenesis

Cusp tip Predentin Dentin till tooth eruption Hydroxyapatite crystals Crystal deposition radially from

centre (spherulite)

classification

1)In number Hypodontia Anodontia Hyperdontia2)In size microdontia macrodontia

3)in shape Gemination Fusion Concrescence Accessory cusp Dens invaginatus Ectopic enamel Taurodontism Hypercementosis Acessory roots dilaceration

In size of teeth

1)Microdontia – teeth physically smaller than usual.i)True generalised microdontia: all teeth smaller than normal uncommon in downs syndrome , pituitary dwarfism ii)Relative generalised microdontia: normal sized teeth in larger jaws. hereditary

iii)Isolated microdontia

common in max lateral incisors(peg shaped crown)

third molars.

Macrodontia/megalodontia

Teeth are physically larger than usual.i)True generalised macrodontia/diffuse: rare all teeth larger than normal. in pituitary

gigantism ,otodental syndrome & pineal hyperplasia with hyperinsulinism.

i

ii) Relative generalised macrodontia: – normal sized teeth

crowed in small jaw. - hereditary.iii)Isolated macrodontia: uncommon in incisors, canine,

second premolar & third molar.

HEMIFACIAL HYPERPLASIA

Treatment and prognosis

Done for aesthetic purpose Peg laterals- full size porcelain

crowns.

In number of teeth

Anodontia

Total lack of tooth development.i)True anodontia/congenital absence of

teeth: all teeth are missing. affect both dentition. rare in hereditary

hypohidrotic ectodermal dysplasia

Anhydrotic ectodermal dysplasia:

Hypodontia

Lack of development of 1/more teeth. common in permanents. Affect third molars, Second premolar,laterals. Associated with microdontia,retained primary, Decrease alveolar development. Non syndromic involment is due to gene

mutation.

Affected gene correlates to missing teeth: AXIN2 gene - second & third molar,second

premolar, lower incisor. Associated with adenomatous polyp of

colon & colorectal carcinoma. PAX9 gene – second molar MSX1 gene – second premolar & third

molar He-Zhao gene – third molar, second

premolar,max laterals.

Syndromes associated with hypodontia

Book’s syndrome:(PHC syndrome) agenesis of premolars hypohidrosis canities white hair

Riegers syndrome:

agenesis of incisors. congenital glaucoma.

Incontinentia pigmenti/bloch- sulzberger syndrome:

peg/cone shaped baldness

Crouzon disease:

early closure of dysostosis acanthosis nigricans hypoplastic maxilla

Ellis van crevold syndrome:

enamel hypoplasia middle upper lip fuse with

max gingival margin. delayed tooth eruption

Apert syndrome

Mid face hypoplasiaSyndactylyShovel shaped incisor

Down syndrome

Enamel hypoplasiaHypo & hyperdontiamacroglossia

Ehler danlos syndrome

Pulp stones Enamel hypoplasia both

Oligodontia

Lack of development of 6/more teeth.

Radiology Panoramic radiographs

Hyperdontia

increase number of tooth Supernumerary- additional teeth Associated with macrodontia. Develop from third tooth bud from

dental lamina. Splitting of permanent bud Local , conditioned hyperactivity of

dental lamina.

Classification of supernumerary

According to morphology :1)Rudimentary abnormal shape & size. Conical Peg shaped, common, as mesiodens Tuberculate barrel shape anterior with> 1 cusp, less

frequent , associated with delayed incisor eruption.

Molariform small molar/premolar like.

2)supplemental: normal size & shape common in max laterals.3)Odontome hamartomas ,included in

odontogenic neoplasm.

According to location:1)Mesiodens in max anterior incisors.

.

2)Distomolars distal to third molar

3)Paramolarlingual /buccal to molar. Supernumerary in soft palate, max

sinus ,nasal cavity, orbit, brain ,sphenomaxillary fissure.

Syndromes associated with hyperdontia

cleidocranial dysplasia

Gardner syndrome

Hallermann streiff syndrome Dicephalia Parrot/beaked nose Mandibular hypoplasia Dwarfism Blue sclera hypertrichosis

Dental transposition- normal teeth erupt into inappropriate position

Commonly involved max. canines , first premolars

Natal teeth – accessory teeth present shortly after birth

Most common mad. Incisors

Neonatal teethTeeth arising with in first 30 days of life

is Arise from bud of accessory dental

lamina.

Treatment & prognosis

Hypodontia is associated with Abnormal spacing of teeth Delayed tooth formation Delayed deciduous tooth exfoliation Late permanent tooth eruption Altered dimension of gnathic regionsSingle missing tooth – no treatment

Multiple teeth – prosthetic replacement with RPD, FPD, osseointegrated implant & resin bonded bridge.

Children – FPD not indicated due to risk of pulp exposure & implant not recommended till completion of skeletal growth.

Orthodontic treatment eliminate need for restorative treatment follow up radiographs since associated with external root resorption.

Radiology Panaromic radiograph with occlusal

& IOPA Natal tooth - extracted if it is mobile

& risk for aspiration. Traumatic ulceration of adjacent soft

tissue is Riga-Fede disease

In shape of teeth

Gemination/schizodontia

attempt of single tooth bud to divide with resultant formation of tooth with bifid crown,common root & canal . single enlarged tooth or joined tooth in which tooth count is normal.

Types of gemination

Both dentition > in max anterior Radiology Enlarged notched crown Two pulp chambers Single root & pulp canal

Fusion/syndontia

union of two normally separated tooth bud with resultant formation of joined tooth with confluence of dentin single enlargement of tooth /joined

tooth tooth count reveals missing tooth.

> in mandible.

Primary- thalidomide induced embropathy

Radiology Two pulp chambers & root canals

Concrescence

union of two teeth by cementum without confluence of dentine

True concrescence -developmental Acquired concrescence –tooth

completion postinflammatory (areas of damage repaired by cementum


Result in crowding , abnormal spacing & delayed /ectopic eruption of permanent

pronounced labial /lingual groove are caries prone so place fissure sealant or composite restoration.

Surgical division & endodontic treatment & full crown.

Concrescence interferes with eruption – surgical removal done.

Extraction difficulties & surgical separation done.

Accessory cusps

Cusp of carabelli Talon cusp Dens evaginatus

Cusp of carabelli

Accessory cusp on palatal surface of mesio lingual cusp of max molar.

In both dentition

Accessory cusp on mesiobuccal cusp of mad permanent /deciduous molar is protostylid

> in first molar

Talon cusp

Is a well delineated additional cusp that is located on anterior tooth extending from CEJ to incisal edge

> in permanent max incisors Resemble eagle’s talon Presence of deep developmental

groove .

R/F - seen in central portion of crown include enamel & dentin

Syndroms associated

Rubinstein taybi syndrome Mohr syndrome Ellis van creveld Incontinentia pigmenti achromias Sturge weber angiomatosis

Dens evaginatus/leong premolar Cusp like elevation of enamel located

in central groove/lingual ridge of buccal cusp of premolar or molar.

Bilateral

•Consist of enamel , dentin, & mostly pulp.

Due to proliferation & evagination of inner enamel epithelium & odontogenic mesenchyme into dental organ during tooth development

R/F – tuberculated appearance & pulpal extension of occlusal surface.

Shovel shaped incisors - affected incisors have prominent lateral margins & hollowed lingual surface resembling scoop of shovel.

Shovel shaped incisor syndrome Interproximal caries Lingual pit caries Periapical & pulpal lesion Shortened & tapered roots


Cusp of carabelli – no treatment. Deep grooves are sealed to prevent caries. Talon cusp – no therapy (mad teeth). In max – interfere with occlusion hence

removal Periodic grinding for tertiary dentin

deposition & pulpal recession , apply fluoride varnish (desensitizing).

After removal , dentin covered with Ca(OH)2 & enamel is etched & composite resin is placed.

Dens evaginatus - occlusal interference eliminated with removal of minimum dentin & treatment with stannous fluoride.

Shovel shaped incisors – restoration of deep fissures to prevent caries.

Dens invaginatus/dens indente

A deep surface invagination of crown/root

lined by enamel.

Due to invagination of surface of tooth crown before calcification occurred.

> max laterals

i)coronal dens invaginatus: Type I – invagination confined to

crown. Type II – extends below CEJ but not

communicating with pulp.

Type III – extends through root & perforate apical / lateral radicular area.

Tooth with in tooth

ii) radicular dens invaginatus – Arise secondary to proliferation of hertwig’s root sheath , with formation of enamel extending along surface of root. Enamel deposition simillar to enamel

pearl.

R/F – enlargement of root dilated invagination lined by

enamel & opening of invagination along lateral aspect of root.

Mild form – pear shaped invagination of enamel & dentin


Type I – restoration of invagination to prevent caries.

If caries – endodontic treatment Type III – temporary placement of

Ca(OH)2 with endodontic treatment Radicular - openings are closed

before pulpal necrosis.

Palato gingival groove Associated with periodontal

defect

Ectopic enamel

Presence of enamel in unusual locations.

i)Enamel pearl /enameloma: Hemispheric structures consist

entirly of enamel/ contain dentin & pulp.

Due to prolonged contact b/t hertwig’s root sheath & developing dentin inducing enamel formation.

1-4 epithelial pearls.> in root furcation /near CEJ. R/F – well defined radiopaque

nodules along root surface.(CEJ)

enamel pearl pulp stone

iii)cervical enamel extension : Dipping of enamel from CEJ towards

bifurcation of molar teeth. Base of triangle is continuous with

coronal enamel.

Buccal bifurcation cyst


Enamel pearl – area of weak point of periodontal attachment .

Oral hygiene maintained to prevent loss of periodontal support.

Flattening / removal of enamel & furcation plasty .

Taurodontism

Enlagement of body & pulp chamber of multirooted tooth , with apical displacement of pulpal floor & bifurcation of root.

Bull like tooth. Unilateral/bilateral. rectangular teeth with pulp

chambers increased apico occlusal height & bifucation close to apex

etiology

Failure of hertwig’s epithelial sheath to invaginate

Mutation resulting from odontoblastic deficiency during dentinogenesis of root. Atavistic feature

Classification

According to degree of apical displacement of pulpal floor:

i)Hypotaurodontism – mildii)Mesotaurodontism - moderateiii)Hypertaurodontism - severe

Hypertaurodont

Radiological features

Rectangular shape Large pulp chambers with > apico

occlusal height. Lack of pulpal constriction ot cervical

region. Short roots Bifurcation few mm above root apex.

Syndrome associated with taurodontism

Tricho dentoosseous syndrome Kinky hair Thin nail Thickening of bones

Klinfelter syndrome Mohr syndrome Down’s syndrome


No specific therapy Significant periodontal destruction

before furcation involvement occurs.

Roots

i) dilaceration Abnormal angulation /bend in root. Mostly idiopathic , but can occur due to

injury , due to cyst /tumour. Mostly in mad third molar, then max

secon premolar, then mad second molar. Deciduous involvement - inappropriate

resorption & delayed eruption of permanent


Extraction of deciduous teeth Endodontic treatment done carefully

to avoid root perforation. Splinting of dilacerated tooth done to

overcome stress related problems , when used as abutment for prosthetic problems

Supernumerary root

Development of increase number of root in tooth.

Both dentition. > in molars than cuspid & premolar Radix entomolaris R/F – some are seen , others

superimposed

radix entomolaris

Hypercementosis/cemental hyperplasia Non neoplastic deposition of

excessive cementum continuous with normal radicular cementum

Generalised - paget’s Disease isolated

radiology thickening/blunting of rootroot outline is enlarged &delineated by PDLspace & lamina dura

hypercementosis

condensing osteitis

Bulbous root

Increased dentin Widened root apex


Detection of accessory root – decrease failure of endodontic treatment

Significance in exodontia.

Screw driver incisors/hutchinson’s teeth

Mulberry molars/fournier molar

Structure of teeth

a)Amelogenesis imperfecta/hereditary enamel dysplasia:

Developmental alteration in structure of enamel in absence of systemic disorders

Classification according to Wit kop (based on phenotype & pedigree.

Type I -HYPOPLASTIC Generalised pitted Localised pitted Localised pitted Diffuse smooth Diffuse smooth Diffuse rough Enamel agenesis

Type II – HYPOMATURATION Diffuse pigmented Diffuse Snow capped Snow capped

Type III- HYPOCALCIFIED Diffuse Diffuse Type IV A– HYPOMATURATION-

HYPOPLASTIC Type IV B –HYPOPLASTIC -

HYPOMATURATION

Mutated genes

1)AMELX gene amelogenin(protein for enamel

formation).2)ENAM gene enamelin3)MMP-20 gene enamelysin(proteinase)4)KLK4 gene kallikrein -4 (proteinase)

5)DLX3 gene code for proteins for

craniofacial, tooth , hair , brain & neural development.

6)AMBN gene ameloblastin

Hypoplastic amelogenesis imperfecta

Inadequate deposition of enamel matrix.

Generalised pattern: Pin point to pinhead sized pits Affect buccal surface Staining of pit

Localised pattern Both dentition Incisal,middle & buccal surface.Autosomal dominant smooth pattern: Enamel is thin hard & glossy Open contact points Opaque white to translucent brown.

Rough pattern: Thin , hard ,rough surfaced enamel. Colour – white to yellowish white Anterior open bite

X linked smooth pattern: Males - diffuse,thin, smooth, & shiny Females – vertical furrows Open bite Brown – yellow brown.

.Enamel agenesis Total lack of enamel formation Yellow brown hue Open contact points

Hypomaturation

defect in maturation of enamel crystals

Normal shape Mottled, opaque, white brown yellow

discoloratioN

Pigmented pattern: Agar brown & mottled enamel Enamel fracture from dentin.X linked pattern : Lyonization seen Focal areas of brown discolouration Males – opaque with translucent mottling Females – vertical bands of white opaque

enamel.

Snow capped pattern: White opaque enamel on

incisal/occlusal one third of crown. Both dentition. Anterior & posterior distribution.

Snow capped

Hypocalcified

Enamel matrix is laid down appropriately but no mineralization.

Enamel is soft & easily lost. Yellow – brown / orange but exhibit

stained brown- black. Coronal enamel is removed with

cervical portion calcified

Amelogenesis imperfecta with taurodontia

hypomaturation/hypoplastic : Both dentition Enamel – mottled yellow- white to

yellow-brown. Buccal side – pits R/F – enamel & dentine same density - large pulp chambers.

Hypoplastic hypomaturation: Enamel – thin R/F - enamel & dentin same density. - large pulp chambers. In tricho -dentoosseous syndrome

CLINICAL FEATURES

Hypoplastic - pitted surface Hypocalcified - soft enamel

removed with Prophylaxis scaler Hypomaturation - can be pierced

by explorer, lost by chipping

radiology

Hypoplastic - tapered crown lack of contact Hypocalcified - no contrast b/t

enamel & dentin Enamel moth eaten appearance Hypomaturation - enamel chips &

abrades

H/F – decalcification – enamel is lost. Ground section of non- decalcified

specimens


Placement of full crowns Severe case – full dentures (over

dentures)

Turner’s tooth

Hypoplasia due to antineoplastic therapy

Environmental enamel hypoplasia

Dentinogenesis Imperfecta

Hereditary developmental disturbance of dentin in absence of systemic disorder.

Mutation of DSPP(dentin sialophosphoprotein) gene

Shield’s classification

a)Dentinogenesis imperfecta I /capdepont teeth/shield’s type II/DI with out osteogenesis imperfecta.

b)Dentinogenesis imperfecta II/ shield’s type I/DI with osteogenesis imperfecta.

c)Dentinogenesis imperfecta III/brandy wine type/shell teeth

DI with out osteogenesis imperfecta/opalescent dentin Blue brown discoloration

DI with osteogenesis imperfecta Genes COL I A1, COL I A 2 code for

type I collagen.

radiology

.bulbous crown.thin roots.obliteration of root canal & pulp

chamber. .cervical constriction.enamel hypoplasia.

Dentinogenesis imperfecta III/brandy wine type/shell teeth Dentin is amber & smooth R/L - enamel normal Thin dentin Enlarged pulp (shell teeth)

Histology

Dentin near enamel is normal, rest abnormal

Atypical odontoblast lining pulp surface are entrapped in defective dentin

Enamel is normal


Crown not recommended ( cervical fracture) , so over lay dentures & teeth covered with Fluorid releasing GIC

Dentin dysplasia

Type I - radicular dentin dysplasia/ rootless teeth

Type II - coronal dentin dysplasia

Rootless tooth

Short root - less root dentin Tooth mobility (premature

exfoliation) Predispose to fracture

O’carroll’s classification of Dentin dysplasia

Type I a

typeI d

Coronal dentin dysplasia

blue–amber-brownR/L – thistle tube/ flamed shape

Pulpal dysplasia

Normal clinically Both dentition thistle tube shaped /

flamed shaped Multiple pulp stones

Histology

Type I coronal enamel & dentin normal

Whorls of dentin & atypical osteodentin (stream flowing around boulders)

Type II numerous interglobular dentin near pulp

Pulp stones


Type I - short root s (early loss from periodontitis)

Pulp channels close to DEJ ( restoratio n & endodontic treatment)

Type II - permanent - endodontic treatment

Regional odontodysplasia/ghost teeth Localised , non hereditary

developmental abnormality of teeth with extensive adverse effect on formation of enamel dentin & pulp

Clinical feature

Yellow to brown , rough surface Dentinal cleft & long pulp horn Max > R/L - short root open apex Thin enamel & dentin Widened pulp chamber Ghost teeth

Histology

Enameloid conglomerates - focal collection of basophilic enamel like calcification.


Retension of altered teeth to pressure surrounding alveolar ridge

Unerupted teeth - left till skeletal growth completes

Erupted teeth - etched retained restoration/stainless steel crowns

Osseointegrated implant after pubertal growth.

references

Text book of oral pathology shafer, hine levy

Colour atlas of common oral diseases langlais miller

Human embryology inderber singh Diagnostic imaging of jaws – langlais

langland Oral 7 maxillofacial pathology

neville damm Orbans oral histology & embrology

Thank you

developmental disturbances of teeth

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