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DENTAL DEFECTS

Tooth Anomalies, sporadic and genetic

CLASSIFICATION

• MORPHOLOGY• NUMBER• SIZE• STRUCTURE• ERUPTION DEFECTS

ALTERATION IN MORPHOLOGY• MICRODONTIA• MACRODONTIA• DILACERATION• DENS IN DENTE• DENS EVAGINATUS• ENAMEL PEARLS• TAURODONTIA• HYPERCEMENTOSIS• FUSION• GEMINATION• CONCRESCENCE• HUTCHINSON’S TEETH

Microdontia

• Focal or Limited – confined to one or only a few teeth

• Peg laterals• Conical teeth – hereditary

ectodermal dysplasia

Microdontia

Conical teeth

Macrodontia

• Focal – a single tooth is enlarged• Generalized – Gigantism• Hemifacial Hypertrophy• Fusion and Gemination

Macrodontia

Dilaceration• Difficult to extract

Dens in dente

• Developmental invagination of enamel organ

• Periapical infections without caries

Dens Invaginatus, apical abscess

Dens Evaginatus

• Evagination of enamel organ• Pulp horn protrudes into

evagenated region

Coronal Anomalies

Cuspal anatomy

Conical crowns

Enamel Pearl (Enameloma)Nodular round smooth deposit of enamel on the root surface

Taurodontia• Elongated pulp chambers (bull teeth)

Hypercementosis

• Osteitis deformans (Paget’s Disease)

• Complicated extractions

Hypercementosis

Fusion• Mergence of contiguous teeth into a single large tooth• Count teeth – one is missing

Gemination

• Duplication of tooth germ into a single large tooth

• Count teeth – none are missing

Concrescence

• Fusion of cementum between contiguous teeth

Congenital Syphilis

HUTCHINSON’S TEETHMulberry Molars

Notched incisors

Mulberry Molars, congential syphilis

Alterations in Number• Decreased numbers

– Partial Anodontia• 2nd bicuspid/3rd molar agenesis,

autosomel dominant, MSXI gene mutation

– Oligodontia– Anodontia– Hereditary Ectodermal Dysplasia– Ellis-van Crevald Syndrome– Incontinentia pigmenti

Partial Anodontia

Mandibular centrals

2nd premolar/3rd molarAgenesis

Hereditary Ectodermal Dysplasia• Inherited as an X-linked recessive, confined to

males. Heterozygotes may show mild manifestations. Rare forms are autosomal recessive.

• Mutation in ED1 gene that encodes ectodysplasin-A (EDA), a tumor necrosis factor family protein

• Anodontia, partial vrs complete• Conical crowns• Anhidrosis, heat intolerant (eccrine agenesis• Lanugo hair• Frontal bossing, saddle nose

Hereditary Ectodermal Dysplasia

HED

Lanugo Hair

Complete Anodontia

Incontinentia Pigmenti

• Skin and oral mucosal white and pigmented lesions

• Missing teeth, delayed eruption• Mutation in proteins involved with • signal transduction (NFkappaB)

Alterations in Number

• Increased Numbers– Supernumerary Teeth

• Mesiodens• Premolars• Paramolars

– Cleidocranial Dysplasia– Gardner Syndrome

Supernumerary Teeth

mesiodens

paramolar

Supernumerary Teeth

Lateral Incisor

Premolar

Cleidocranial Dysplasia

• Clavicular Agenesis• Supernumerary teeth• Multiple impactions• Cranial ossification anomalies

Cleidocranial Dysplasia: Clavicular Agenesis

Cleidocranial Dysplasia

Cleidocranial Dysplasia: Dental Changes

Supernumeraty Impacted Teeth

Gardner SyndromeAdenomatous Polyposis Syndrome

• Premalignant Colonic Polyps that transform into adenocarcinomas

• Hereditary loss or mutation of the tumor suppressor gene APC1

• Multiple osteomas of the craniofacial bones

• Multiple supernumerary impacted teeth

Gardner Syndrome

Tooth Wear and Loss of Structure

• Attrition• Abrasion• Erosion

– Subcervical Erosion• Enamel hypoplasia• Fracture

Attrition

• Physiologic wear, course diet

Abrasion

• Pathologic Tooth Wear

carpenter

toothbrush

Erosion• Idiopathic loss of tooth structure• Defective DEJ, acidic foods, regurgitation

Bulemia> Gastric Acid Erosion of the lingual surfaces

Enamel Hypoplasia• Linear pitted loss of enamel

corresponding to date of precipitating event (fever).

• In today’s world, fevers are usually controlled with antipyretic analgesics; hence, hypoplastic dental changes are very rare.

• Delve into potential heritable cause – c/w pitted hypoplastic form of

amelogenesis imperfecta– Pitted enamel in Tuberous

Sclerosis• Turner’s tooth

Turner’s ToothInfection of deciduous tooth, usually an anterior tooth,

causing damage to underlying secondary tooth

Coronal Fracture

Alterations in Structure• Fluorosis• Amelogenesis imperfecta• Dentinogenesis imperfecta• Dentin dysplasia• Cemental agenesis (hypophosphatasia)• Hypophosphatemia (Vit D refractory

rickets)• Regional Odontodysplasia• Internal and External Root Resortion

Fluorosis• Fluoride ion in excess of 1 ppm in

drinking water, encountered in well water and assimilated into developing teeth.

• Mottled enamel, brown and chalky white.

Amelogenesis Imperfecta• Various forms with differing modes of

inheritance– Specific mutations have been discovered, many

involving the amelogenin and enamelin enamel proteins

• Three major phenotypes– Hypomaturation: enamel is structurally defective and

soft, often being discolored– Hypoplastic: enamel is sound structurally, yet is thin, a

defect in quantitative synthesis– Hypocalcification: enamel matrix is formed, yet

hydroxyappatite crystal formation is defective, leaving punctate pits similar to acquired enamel hypoplasia

Amelogenesis Imperfecta

HYPOPLASTICTYPE

AMELOGENESIS IMPERFECTASnow Capped Teeth

Amelogenesis ImperfectaPigmented Hypomaturation

Amelogenesis ImperfectaHypoplastic Pitted

Dentinogenesis Imperfecta• Dentin is defective with haphazardly arranged dentinal tubules• Autosomal dominant

– Type I: DGI1 (DI with OI) > COLIA1 and COLIA2, genes that encode the α-1 and α-2 chains of type I collagen

– Type II: DGI2 > (DI alone with mutation in dentinal sialoprotein) – Type III: DGI3 (Brandywine type) > mutations in Dentin

sialophosphoprotein gene, sialoprotein fraction (DSP)• Pulp chambers are obliterated• Spike shaped roots• Enamel is sound, yet DEJ adhesion is poor and it therefore flakes

away• Once enamel goes, the defective dentin is rapidly abraded away,

being most severe in DGI3 where pulp exposures are common• Association with osteogenesis imperfecta (DGI1)

– Multiple fractures– Blue sclera

Dentinogenesis Imperfecta (DGI2)

“opalescent teeth”

Dentinogenesis imperfecta

“pulpless teeth”

Dentinogenesis Imperfecta with Osteogenesis Imperfecta (DGI1)

• Autosomal dominant heritable disease, mutations in type 1 collagen genes

• Dentinogenesis imperfecta exhibits same appearance as the uncomplicated form

• Osteogenesis imperfecta is characterized by weak fragile bones with a history of multiple fractures

• Blue Sclera• Diminutive stature• Truncated life span

Dentinogenesis/Osteogenesis Imperfecta (DGI1)

Blue sclera

“Pulpless teeth”

Dentin dysplasia type I• Heritable disorder involving dentin

and radicular morphogenesis• “Rootless” teeth; normal appearing

crowns• Crescent shaped pulp chambers• Microscopically, the dentin is

markedly altered with a cascade-like pattern.

• Premature tooth loss

Dentin Dysplasia type I

Dentin Dysplasia Type I

Dentin Dysplasia type II• Heritable disorder involving

entire dentition• Mutation in Dentin

sialophosphoprotein, phosphoprotein fraction (DDP)

• Large pulp chambers• Large pulp stones• Thistle shaped radicular canals• Normal appearing crowns

Dentin Dysplasia Type II

Martini glass teeth

Cemental Agenesis• Hypophosphatasemia (Hypophosphatasia)• Autosomal recessive defect in alkaline

phosphatase, an enzyme critical for phosphorylation of osteoid matrix (1p36-p34)

• A milder autosomal dominant form also occurs

• Rachitic bone changes in children, osteomalacia in adults

• Premature exfoliation of teeth due to defective PDL-cementum adhesion

Hypophosphatasia

Cemental agenesis

Premature exfoliation

Vitamin D Dependent Hereditary Rickets

• Inherited as an autosomal dominant trait with inability to form 1α,25 dihydroxy-Vit D3– Type I – mutation in 1α hydroxylase– Type II – mutation in vitamin D receptor complex

• Coronal fissures in which bacteria can gain access to the pulp in the absence of carious lesions

• Periapical radiolucencies representing spread of endodontic infection

• Generalized features in common with vitamin D deficient rickets (without response to vitamin therapy)

Coronal Fissures, Apical InfectionsVitamin D Refractory Rickets

Regional Odontodysplasia• Sporadic• Deficient odontogenesis of all dental

hard tissues in a focal area• Usually 3-4 teeth involved• Ghost teeth of Rushton• Spheroidal calcifications seen

histologically in the dental follicles of affected areas

• Anomalous vascular tissue in region

Ghost Teeth

Regional Odontodysplasia

• Peridental soft tissues

Discoloration/Pigmentation• Dental decay• Pink Tooth of Mummery (coronal internal resorption)• Pulpal necrosis • Congenital Jaundice

– Hepatitis, Biliary Atresia, Hemolytic Anemia: bilirubin pigment incorporated into developing dentin

• Fluorosis• Amelogenesis imperfecta• Dentinogenesis imperpecta• Extrinsic pigmentation

Pigmentations

FLUOROSIS NECROTIC PULP

PINK TOOTH (INTERNAL RESORPTION) DENTINOGENESIS IMPERFECTA

PIGMENTATIONS

TETRACYCINE AMELOGENESIS IMPERFECTA

Delayed Eruption• Hypopituitarism• Hypothyroidism (Cretinism)• Impaction

– Third molars>cuspids– Overlying neoplasms (e.g.:

odontoma)– Cleidocranial dysplasia– Cherubism

Impaction

Cysts

Odontomas preventing eruption

Premature Tooth Loss

• Juvenile Periodontitis• Langerhans Cell Histiocytosis• Hypophosphatasia• Vitamin C Deficiency• Neoplasms

Tooth Resorption

• External– Idiopathic– Post Orthodontic Therapy– Pathologic Processes– Subcervical Erosion

• Internal

Subcervical Erosion• Idiopathic loss of enamel, cementum and dentin in the cervical region

External Resorption

Pathologic Processes

Incomplete Development

History of Radiation to Head and Neck