tooth developmental defects

anodontia

total lack of tooth development

ankylosis

cessation of eruption after emergence, fusion of cementum w bone, unknown pathogenesis

concrescence

union of two teeth by cementum alone

dens in dente

“a tooth within a tooth”, developmental anomaly that results when the enamel organ invaginates into the crown of a tooth before mineralization

dentinogenesis

formation of dentin

dilaceration

an abnormal bend or curve in reference to the root of a tooth

fusion

two tooth buds try to join and create a single enlarged/joined tooth resulting in a missing tooth count

gemination

one tooth bud tries to divide in which the tooth count is normal

hypodontia

a few missing teeth, 1-5; associated w ectodermal dysplasia; teeth present are usually abnormal in shape

impacted teeth

embedded teeth that cannot erupt into the oral cavity bc of a physical obstruction

macrodontia

abnormally large teeth

microdontia

abnormally small teeth

oligodontia

a subcategory of hypodontia in which 6 or more teeth are missing

supernumerary

excess number of teeth; associated w Gardener’s Syndrome and Cleidocranial Dysplasia

are permanent or primary teeth more affected by hypodontia

permanent- 3rd molars

dx

hypodontia

origin of hypohidrotic ectodermal dysplasia

inherited condition via AD, AR, X-linked, where 2 or more ectodermally derived anatomic structures fail to develop

clinical manifestations of hypohidrotic ectodermal dysplasia

• heat intolerance

• fever

• hypodontia

• fine, sparse hair

• reduced eyebrows and eyelashes

• periocular skin shows wrinkling and

• hyperpigmentation

what are the most common teeth you will see in hyperdontia

max incisor > max 4th molar > mand 4th molar

what is mesiodens

type of hyperdontia referring to maxillary incisors (most common)

what is distomolar/distodens

type of hyperdontia referring to accessory 4th molar

what is paramolar

type of hyperdontia referring to situated lingually or buccally to a molar

what syndromes should be assessed if a pt have hyperdontia

Gardener’s Syndrome and Cleidocranial Syndrome

type of hyperdontia

mesiodens

type of hyperdontia

distomolar/distodens

type of hyperdontia

paramolar

what are natal teeth

teeth present at birth

what are neonatal teeth

teeth present within the first 30 days

mode of inheritance for cleidocranial dysplasia

AD

clinical manifestations of cleidocranial dysplasia

• prolonged retention of deciduous teeth

• delay or failure or eruption of permanent teeth

• abnormally shaped teeth

• numerous unerupted permanent and supernumerary teeth

• clavicle abnormalities

Gardener Syndrome mode of inheritance

AD, mutation in chromosome 5 (APC)

clinical manifestations in Gardener Syndrome

• colorectal polyps (can become malignant)

• multiple osteoma (bone tumor in head)

• epidermoid cysts of skin

• supernumerary teeth

• thyroid carcinoma

• pigmented ocular fundus (90%)

is hyperdontia more commonly found in gardeners syndrome or cleidocranial dysplasia

cleidocranial dysplasia

is microdontia often associated w hypodontia or hyperdontia

hypodontia

what tooth is most affected by microdontia

lateral incisors- peg laterals

microdontia can be associated w what syndromes

• down syndrome

• hypopituitarism (dwarfism)

is isolated or generalized macrodontia more common, which tooth/teeth

isolated; incisors and canines

if macrodontia is generalized, this is rare, but it may be associated w…

systemic conditions

what are where is the cusp of carabelli

accessory cusp on ML of maxillary molars that may contain pulp tissue

what and where are talon cusps

accessory cusp on lingual of maxillary (lateral) incisor that may contain pulp tissue

what is dens evaginatus/occlusal pearl

elongated cusp extending from central occlusal surface that usually contains pulp tissue

what teeth are most common in dens evaginatus

mandibular premolars, then maybe molars

dx

hyperdontia/supernumerary

dx

microdontia

dx

macrodontia

dx

gemination

dx (by cementum only)

concrescence

dx (two teeth join together)

fusion

dx

cusp of carabelli

dx

talon cusp

dx

dens evaginatus/occlusal pearl

des invaginatus, AKA, dens in dente, can be coronal or radicular, what are the three types

• type I: invagination is confined to crown

• type II: invagination extends below the CEJ

• type III: invagination may extend through the root

dx

type I dens in dente/dens invaginatus

dx

type II dens in dente/dens invaginatus

dx

type III dens in dente/dens invaginatus

what are shovel shaped teeth

prominent marginal ridges on maxillary incisors- especially centrals

shovel shaped teeth can be associated w…

dens evaginatus/occlusal pearls

is shovel teeth usually uni- or bilateral

bilateral

shovel teeth are most common in ..

Asians

dx

shovel teeth

what are enamel pearls

enamel nodules at furcations of multi-rooted teeth that contain pulp tissue but no dentin

where are enamel pearls most common

maxillary molars

what problems can present w enamel pearls

perio defects and pulp exposures

dx

enamel pearl

what is taurodontism

enlargement of the body and the pulp chamber of a tooth; is associated w many syndromes

where is taurodontism most common

mandibular molars and premolars

dx

taurodontism

where is dilaceration is most common

3rd molars

what problems can present w dilaceration

if endo or ext is needed

dx

dilaceration

what can hypercementosis be caused by

• local factors (localized)

• systemic factors (generalized)

what local factors can cause hypercementosis

• abnormal occlusal trauma

• adjacent inflammation

• unopposed teeth (super eruption)

• repair of vital root fx

what are some systemic factors that can cause generalized hypercementosis

• paget disease of bone

• Gardener syndrome

what teeth are most affected by hypercementosis

mandibular molars, then 2nd premolars

dx- only #4

localized hypercementosis

dx- #27, 28, 29

generalized hypercementosis

what is a supernumerary root

inc in number of roots in either primary or secondary teeth

what teeth are most common in supernumerary roots

mandibular 3rd molars > cuspids and bicuspids

dx

supernumerary root of #30

mode of inheritance of amelogenesis imperfecta

AD, AR, X-linked

what is amelogenesis imperfecta

affects the enamel making it soft and thin, easily damaged, and susceptible to decay and will leave dentin exposed; can show has yellow-brown to white pitted lesions and open bite/loss of contacts

what are the types of amelogenesis imperfecta

• hypoplastic (pitted)

• hypomaturation/hypocalcification (snow capped)

• amelogenesis imperfecta w taurodontism

dx

hypomaturation amelogenesis imperfecta- snow capped

dx

hypoplastic amelogenesis imperfecta- pitted pattern

what are the two types of enamel dysplasia

hypoplasia and hypomineralization

is hypoplasia a quantitative or qualitative defect

quantitative defect

is hypomineralization a quantitative or qualitative defect

qualitative defect

what is hypoplasia

thickness deficit in the quantity of minerals

what is hypomineralization

mineral deficit

what other two conditions branch off hypomineralization

hypomaturation and hypocalcification

what is hypomaturation

amelogenin-rich

what is hypocalcification

amelogenin-poor

what condition branches off of hypocalcification

molar hypomin

what is molar hypomin

• albumin rich

• amelogenin poor

• acquired defect

what are the three shields classifications of dentinogenesis imperfecta

• DGI I

• DGI II

• DGI III

what is the witkop classification for DGI I

dentinogenesis imperfecta

what is the witkop classification for DGI II

hereditary opalescent teeth

what is the witkop classification for DGI III

brandywine teeth

DGI I clinical presentation

• osteogenesis imperfecta (for boards)

• opalescent teeth

• bone fractures

DGI II clinical presentation

• isolated opalescent teeth

• MOST COMMON