DEVELOPMENTAL DISTURBANCES OF THE TEETH...Macrodontia 12/7/2015 6 Macrodontia (1) True Generalized Macrodontia (2) Relative Generalized Microdontia (3) Focal or Localized Macrodontia

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DEVELOPMENTAL

DISTURBANCES OF THE TEETH

Dr. Ibtisam Briek SENUSSI

Oral pathology

19.11.2015

(1) Size

(2) Number and Eruption

(3) Shape/Form

(4) Defects of Enamel and Dentin

Developmental Disturbances

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Microdontia

Macrodontia

Size

Microdontia

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Microdontia

(1) True Generalized Microdontia

(2) Relative Generalized Microdontia

(3) Focal or Localized Microdontia

Size

All teeth are smaller than normal

Occur in some cases of pituitary dawrfism

Exceedingly rare

Teeth are well formed

(1) True Generalized Microdontia

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Normal or slightly smaller than normal teeth

Are present in jaws that are somewhat larger than

normal


Common condition

Affects most often maxillary lateral incisior + 3rd molar

These 2 teeth are most often congenitally missing

(3) Focal/Localized Microdontia

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Common forms of localized microdontia is that which

affects maxillary lateral incisor

Peg lateral

Instead of parallel or diverging mesial + distal surfaces

(3) Focal/Localized Microdontia

sides converge or taper together incisally

forms cone-shaped crown

root is frequently shorter than usual

Macrodontia

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Macrodontia

(1) True Generalized Macrodontia


(3) Focal or Localized Macrodontia

Size

All teeth are larger than normal

Associated with pituitary gigantism

Exceedingly rare

(1) True Generalized Macrodontia

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Normal or slightly larger than normal teeth in small

jaws

Results in crowding of teeth

Insufficient arch space

(2) Relative Generalized Macrodontia

Uncommon condition

Unknown etiology

Usually seen with mandibula3rd molars

(3) Focal/Localized Macrodontia

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(1) Size


(3) Shape/Form



Supernumerary

Anodontia

Impaction

Number and Eruption

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Supernumerary

Results from continued proliferation of permanent or

primary dental lamina to form third tooth germ

Teeth may have:

• normal morphology

• rudimentary

• miniature

Number and Eruption

Supernumerary

More often in permanent dentition than primary

dentition

More in the maxilla than in mandible

Number and Eruption

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Supernumerary

May be impacted erupted or impacted

Because of additional tooth bulk, it causes:

• Malposition of adjacent teeth

• Prevent their eruption

Number and Eruption

Supernumerary

Many are impacted

• Characteristically found in cleidocranial dysostosis

Number and Eruption

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Number and Eruption

Supernumerary

Mesiodens

Fourth molar

• Maxillary Paramolar

• Distomolar or Distodens

Mandibular Premolar

Maxillary lateral incisors

Number and Eruption

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Supernumerary

Mandibular central incisors

Maxillary Premolars

Number and Eruption

Most common supernumerary tooth

Tooth situated between maxillary central incisors

Singly , Paired , Erupted or impacted , Inverted

Mesiodens

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Small tooth

Cone-shaped crown

Short root

Mesiodens

Small + rudimentary

Situated bucally or lingually to one of the maxillary

molars

Interproximally between 1st + 2nd or 2nd + 3rd maxillary

molars

Para-molar

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Molar located distal to molar

Distomolar / Distodens

2nd most common

Situated distal to 3rd molar

Small rudimentary tooth, but may be of normal size

Mandibular 4th molar also is seen occasionally, but less

common than maxillary molar

Fourth Molar

Distomolar

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Anodontia

lack of tooth development

absence of teeth

Number and Eruption

Anodontia

Complete Anodontia

Partial Anodontia

• Hypodontia

• Oligodontia

Pseudoanodontia

False Anodontia

Number and Eruption

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When all teeth are missing

Rare

Often associated with a syndrome known as hereditary

ectodermal dysplasia

Complete Anodontia

Lack of development of one or more teeth

Hypodontia

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Lack of development of six or more teeth

Oligodontia

When teeth are absent clinically because of impaction

or delayed eruption.

Pseudo - Anodontia

When teeth have been exfoliated or extracted

False Anodontia

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Impaction

most often affects the mandibular 3rd molars +

maxillary canines

less commonly:

• premolars

• mandibular canines

• second molar

Number and Eruption

Impaction

Occurs due to obstruction from crowding

From some other physical barrier

Occasionally, may be due to an abnormal eruption

path, presumably because of unusual orientation of

tooth germ

Number and Eruption

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Impaction

Ankylosis

Number and Eruption

fusion of a tooth to surrounding

bone

with focal loss of periodontal

ligament, bone + cementum

become inextricably mixed

cause fusion of tooth to

alveolar bone

Ankylosis

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(1) Size


(3) Shape/Form



Crown

Root

Shape and Form

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Crown

Fusion

Gemination

Taurodontism

Talon’s Cusp

Leong’s Cusp

Shape and Form

Crown

Dens Invaginatus

Peg-shaped Lateral

Hutchinson Incisor

Mulberry Molar

Shape and Form

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Root

Concresence

Enamel Pearl

Dilaceration

Flexion

Ankylosis

Shape and Form

Joining of 2 developing tooth germs

Resulting in a single large tooth structure

May involve entire length of teeth

Or may involve roots only, in which case cementum +

dentin are SHARED

Fusion

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Fusion

Fusion of 2 teeth from a single enamel organ

Partial cleavage

Appearance of 2 crowns that share same root canal

Trauma has been suggested as possible cause,

the cause is still unknown

Gemination

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Variation in tooth form:

Elongated crowns

Apically displaced furcations

• Resulting in pulp chambers that have apical

occlusal height

Taurodontism

May be seen as isolated

incident in families

Associated with syndromes

such as

Down syndrome

Taurodontism

little clinical significance

No treatment is required

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Talon’s Cusp

Leung’s Premolar

Dens Evaginatus

Well-delineated additional

cusp

Located on the surface of

an anterior tooth

Extends at least half the

distance from CEJ to

incisal edge

Talon’s Cusp

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Developmental condition

Clinically as an accessory cusp or a globule

Located on occlusal surface between buccal + lingual

cusps of premolars

Unilaterally or bilaterally

Leung’s Cusp

Deep surface invagination of crown or root that is

lined by enamel

2 forms:

Coronal

Radicular

Dens Invaginatus (Dens in Dente)

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Depth varies from slight enlargement of cingulum

to a deep in-folding that extends to apex

Historically, it has been classified into 3 major

types:

Type I

Type II

Type III


Type I

• Confined to the crown

Type II

• Extends below cemento-enamel

junction

• Ends in a blind sac

• May or may not communicate

with adjacent dental pulp


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Type III

• Extends through the root

• Perforates in the apical or lateral

radicular area without any

immediate communication with

pulp


Undersized lateral incisor

Smaller than normal

Occurs when permanent lateral incisors do not fully

develop

Peg-Shaped Lateral

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Characteristic of congenital

syphilis

Lateral incisors are peg-shaped

or screwdriver-shaped

Widely spaced

Notched at the end

With a crescent-shaped

deformity

Hutchinson’s Incisor

Notches on their biting surfaces

Named after Sir Jonathan Hutchinson

English surgeon + pathologist who 1st described it

Hutchinson’s Incisor

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Dental condition usually associated with congenital

syphilis

Characterized by multiple rounded rudimentary enamel

cusps on permanent 1st molars

Mulberry Molar

Dwarfed molars with cusps covered with globular enamel

growths

Giving the appearance of a mulberry

Mulberry Molar

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Root

Concresence

Enamel Pearl

Dilaceration

Flexion

Ankylosis

Shape and Form

2 fully formed teeth

Joined along the root surfaces

by cementum

Noted more frequently in

posterior and maxillary regions

Concrescence

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often involves a 2nd molar

tooth in which its roots

closely approximate the

adjacent impacted 3rd molar

may occur before or after the

teeth have erupted

usually involves only 2 teeth

Concrescence

Diagnosis can frequently be established by routine

graphic examination

Often requires no therapy unless union interferes

with eruption; then surgical removal may be warranted

Since with fused teeth, extraction of one may result in

extraction of the other

Concrescence

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Droplets of ectopic enamel

Or so called enamel pearls

May occasionally be found on

roots of teeth

Uncommon, minor abnormalities,

which are formed on normal

teeth

Enamel Pearls

Occur most commonly in bifurcation or trifurcation of teeth

May occur on single-rooted premolar as well

Maxillary molars are commonly affected than mandibular

molars

Enamel Pearls

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May cause stagnation at gingival margin but, if they

contain pulp, this will be exposed when pearl is removed

Enamel Pearls

Consist of only a nodule of enamel attached to dentin.

May have a core of dentin containing pulp horn.

May be detected on radiographic examination.

Angulation or a sharp bend

or curve in root or crown of

a formed tooth

Trauma to a developing tooth

can cause root to form at an

angle to normal axis of tooth

Rare deformity

Dilaceration

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Movement of crown or of the crown and part of root

from remaining developing root may result in sharp

angulation after tooth completes development

Dilaceration

Hereditary factors are believed to be involved in small

number of cases

Eruption generally continues without problems

Dilaceration

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Deviation or bend restricted just to the root portion

Usually bend is less than 90 degrees

May be a result of trauma to the developing tooth

Flexion

Also known as “submerged teeth”

Fusion of a tooth to surrounding bone

Deciduous teeth most commonly mandibular 2nd molars

Undergone variable degree of root resorption

Ankylosis

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Have become ankylosed to bone

This process prevents their exfoliation + subsequent

replacement by permanent teeth

After adjacent permanent teeth have erupted,

ankylosed tooth appears to have submerged below

level of occlusion

Ankylosis

THANKS

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NATAL TEETH

These are extra teeth that are present at birth.

Cause:

A developmental disturbance creating intracellular

activity during the first stage of tooth development (bud

stage) can result in the development of extra teeth.

The most common natal teeth are lower incisors.

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Treatment:

These teeth are defective and their removal is

generally recommended, particularly if mobility poses

a threat of aspiration. These teeth also make feeding

difficult.

Natal Teeth 19.11.15

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NEONATAL TEETH

These are primary teeth that erupt prematurely

(during the first few weeks of life).

Cause:

Premature tooth eruption.

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Treatment These teeth are usually normal primary teeth and should be

retained. An x-ray will be taken if possible to confirm that

these are not extra teeth.

Neonatal Teeth

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• Accessory roots are most commonly seen in mandibular

canines, premolars and molars ( especially third molar).

• Very rare in maxillary anterior teeth & mandibular

incisors.

• Discovered in routine radiographic examination .

• This condition important in extraction of teeth and RCT.

• Supernumerary Roots

Shape and Form 19.11.15

(1) Size


(3) Shape/Form


Developmental

Disturbances

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also known as:

Hereditary Enamel Dysplasia

Hereditary Brown Enamel

Hereditary Brow Opalescent

Teeth

Amelogenesis

Imperfecta

group of conditions caused by

defects in the genes encoding

enamel matrix proteins

genes that encode for enamel

proteins:

amelogenin mutated in

enamelin in patients

others with this

condition

Amelogenesis

Imperfecta

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affects both dentition

deciduous

permanent

classified based on pattern of

inheritance:

hypoplasia

hypomaturation

hypocalcified

Amelogenesis

Imperfecta

No treatment except for

improvement of cosmetic

appearance

Amelogenesis

Imperfecta

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inadequate formation of matrix

enamel is randomly:

pitted

grooved or very thin

hard + translucent

defects become stained but teeth

are not especially susceptible to

caries unless enamel is scanty

and easily damaged

Hypoplastic

Amelogenesis Imperfecta

reduced enamel thickness

abnormal contour

absent interproximal

contact points

Radiographically:

enamel reduced in bulk

shows thin layer over occlusal

+ interproximal surfaces

Hypoplastic


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dentin + pulp chambers

appear normal

no treatment is necessary

Hypoplastic


enamel is normal in form on

eruption but:

opaque

white to brownish-yellow

softer than normal

tends to chip from

underlying

dentin

Hypomaturation


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Radiographically:

affected enamel exhibits

radiodensity similar to

dentin

Hypomaturation


enamel matrix is formed in

normal quantity

poorly calcified

when newly erupted:

enamel is normal in thickness

normal form

but weak

opaque or chalky in appearance

Hypocalcified


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with years of function:

coronal enamel is removed

except for cervical portion

that is occasionally calcified

better

Radiographically:

density of enamel + dentin are

similar

Hypocalcified


also known as “Hereditary

Opalascent Dentin”

due to clinical discoloration

of teeth

mutation in the dentin

sialophosphoprotein

affects both primary + permanent

dentition

Dentinogenesis Imperfecta

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have blue to brown

discoloration

with distinctive translucence

enamel frequently separates

easily from underlying defective

dentin


Radiographically:

bulbous crowns

cervical constriction

thin roots

early obliteration of roots

canals + pulp chambers


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Treatment:

prevent loss of enamel +

subsequent loss of dentin

through attrition

cast metal crowns on posterior

jacket crowns on anterior

teeth


Classification:

Type I

Type II

Type III


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occurs in families with

Osteogenesis Imperfecta

primary teeth are more severely

affected than permanent teeth

Type I Dentinogenesis

Imperfecta

Radiographically:

partial or total obliteration

of pulp chambers + root canals

by continued formation

of dentin

roots may be short + blunted

cementum, periodontal

membrane + bone appear

normal

Type I Dentinogenesis

Imperfecta

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never occurs in association

with osteogenesis imperfecta

unless by chance

most frequently referred to as

hereditary opalascent dentin

only have dentin abnormalities

and no bone disease

Type II Dentinogenesis

Imperfecta

Radiographically:

partial or total obliteration

of pulp chambers + root canals

by continued formation

of dentin

roots may be short + blunted

cementum, periodontal

membrane + bone appear

normal

Type II Dentinogenesis

Imperfecta

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“Bradwine type”

racial isolate in Maryland

multiple pulp exposures in

deciduous not seen in type

I or II

periapical radiolucencies

Type III Dentinogenesis

Imperfecta

enamel appears normal

large size of pulp chamber

is due not to resorption but

rather to insufficient + defective

dentin formation

Type III Dentinogenesis

Imperfecta

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also known as “Rootless Teeth”

rare disturbance of dentin

formation

normal enamel

atypical dentin formation

abnormal pulpal morphology

hereditary disease

Dentin Dysplasia

Classification:

Type I (Radicular Type)

Type II (Coronal Type)

Dentin Dysplasia

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both dentitions are of

normal color

periapical lesion

premature tooth loss may occur

because of short roots or

periapical inflammatory lesions


Radiographically:

roots are extremely short

pulps almost completely

obliterated

periapical radiolucencies:

• granulomas

• cysts

• chronic abscesses


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color of primary dentition

is opalescent

permanent dentition is normal

coronal pulps are usually large

(thistle tube appearance)

filled with globules of abnormal

dentin


Radiographically:

(Deciduous)

roots are extremely short

pulps almost completely

obliterated

(Permanent)

abnormally large pulp

chambers in coronal portion of

tooth


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also known as:

Odontogenic Dysplasia

Odontogenesis Imperfecta

Ghost Teeth

Regional

Odontodysplasia

one or several teeth in a

localized area are affected

maxillary teeth are involved

more frequently than

mandibular area

etiology is unknown

Regional

Odontodysplasia

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teeth affected may exhibit

a delay or total failure in

eruption

shape is altered, irregular

in appearance

Regional

Odontodysplasia

Radiographically:

marked reduction in

radiodensity

teeth assume a “ghost”

appearance

both enamel + dentin appear

very thin

pulp chamber is exceedingly

large

Regional

Odontodysplasia

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Treatment:

poor cosmetic appearance

of teeth

extraction with restoration

by prosthetic appliance

Regional

Odontodysplasia

normal thickness enamel

extremely thin dentin

enlarged pulps

thin dentin may involve

entire tooth or be isolated

to the root

most frequently in deciduous

Shell Tooth

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References:

Books Cawson, R.A: Cawson’s Essentials of Oral

Oral Pathology and Oral Medicine,

8th Edition

• (pages 24-36)

Neville, et al: Oral and Maxillofacial Pathology

3rd Edition

• (pages 77-113)

Regezi, Joseph et al: Oral Pathology, Clinical

Pathological Correlations

5th Edition

• (pages 361-373)

Shafer, et al: A textbook of Oral Pathology,

3rd Edition • (pages 37-69)

DEVELOPMENTAL DISTURBANCES OF THE TEETH...Macrodontia 12/7/2015 6 Macrodontia (1) True Generalized Macrodontia (2) Relative Generalized Microdontia (3) Focal or Localized Macrodontia

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