Dental Abnormalities Flashcards
Hyperodontia
Teeth in excess of the normal
complement
- Maxillary incisors -
mesiodens
- Maxillary fourth molars
(2)
- distodens,
- paramolars
- Mandibular fourth molars
(2)
- distodens,
- paramolars
Hyperdontia - multiple teeth
Most common in — area
premolar
Syndromes with multiple teeth
(2)
- Cleidocranial Dysplasia
- Gardner
Cleidocranial Dysplasia
(2)
- Frontal & parietal bossing
- Clavicular aplasia
Gardner Syndrome
(5)
- Autosomal dominant
- Multiple osteomas including the jaws
- Colorectal polyps with malignant potential
- Multiple supernumerary teeth
- Lesions of skin (cutaneous epidermoid cysts
and fibromas)
Problems with
Supernumeraries
(2)
- Affect eruption of normal complement of
teeth - Cystic degeneration of follicular
epithelium
Hypodontia
less than the normal tooth
complement of an existing dentition;
permanent or deciduous
less than one or more of an existing
dentition; permanent or deciduous
Anodontia
congenital absence of all teeth
- Anodontia –
agenesis of all teeth
- Oligodontia –
congenital lack of > 6
permanent teeth, excluding third molars
- Hypodontia –
less than one or more of
an existing dentition; permanent or
deciduous
TYPES
(3)
- Acquired
- Syndromal
- Reduction phenomenon
- Reduction phenomenon
(4)
- Third Molar Agenesis
- Maxillary Lateral Incisors
- Microdontia
- Isolated Agenesis
Hypodontia
less than the normal tooth
complement of an existing dentition
Most common
Acquired
Syndromes with missing teeth
~— syndromes
150
Syndromes with missing teeth
(5)
- ectodermal dysplasia
- oligodontia-colorectal cancer syndrome
- ectodermal dysplasia with oligodontia-
colorectal cancer syndrome - otodental dysplasia – associated with
deafness - Rieger Syndrome – associated with
deafness
- oligodontia-
colorectal cancer syndrome
- ectodermal dysplasia with oligodontia-
colorectal cancer syndrome
- otodental dysplasia –
associated with
deafness
- Rieger Syndrome –
associated with
deafness
Reduction Phenomenon
(3)
- Hypodontia not associated with other
multiple system congenital syndrome - Seen with third molars and maxillary
lateral incisors - Evolutionary trend ?
Third molar hypodontia
Woolf, 1971
* Incidence of 1 – 4 missing is;
10-25%
Third molar hypodontia
Hellman 1936
* Incidence of 1 – 4 missing is…
29.6%
1 missing …
2 missing…
3 missing…
4 missing…
8.9%
10.0%
4.4%
6.3%
Agenesis of Maxillary Lateral Incisor
AMLI
(3)
- Uni/bilateral reduction, i.e., peg lateral
maxillary inmcosor - Uni/bilateral agenesis
- a variable manifestation hypodontia
Non-Third molar hypodontia
* Graber 1978 -
* Jorgenson 1980 –
1.6 –9.6% (median 5.6%)
6.0-7.0%
skipped
Anomalies (other)
- Macrodonts
- Dilaceration
- Supernumerary roots
- Non-carious loss of tooth structure – erosion
- Attrition
-abrasion - Taurodont
- Dens Invaginatus
- Talon Cusp
- Drift vs. Migration
- Impacted Teeth
Macrodont
Bulky Incisor or Double tooth
phenomenon
Dilaceration
(3)
- Abnormal angulation
or bend in the root
(and occasionally
the crown) of a tooth - Some related to
trauma during
odontogenesis - idiopathic
Supernumerary Roots
- Extra roots above
the complement
of roots classically
described for the
dentition
Supernumerary Roots
* Significant for
- Appear to be
excellent
endodontic or
exodontic
considerations
prosthodontic
abutments
Li Root of Mandibular First
Molars
* —% incidence in
Asians in a Chinese
population (Hong
Kong and Taiwan)
* —% in native
North American
populations
20
10-12
Attrition –
physiologic wear of teeth
Abrasion –
mechanical wear of teeth
Erosion –
chemical wear of teeth
Taurodont
(2)
- Idiopathic developmental
disorder of odonogenesis
causing elongation of the
pulp chamber (aka apical
displacement of the
pulpal floor) and shorter
root appendages - failure of Hertwig’s
epithelial sheath
diaphragm to invaginate
at the proper horizontal
level, resulting in a tooth
with short root, enlarged
body, an enlarged pulp
and normal dentin
Taurodont
* Treatment complications if
endodontic
treatment or extractions are needed
Dens Invaginatus
Dens in Dente
* —% incidence
* Primarily seen in
0.04 – 10
lateral incisors but
also centrals,
premoalrs, centrals,
canines…..
Dens Invaginatus
Dens in Dente
* Type I –
* Type II –
* Type III –
coronal
extends
apical to CEJ
extends
through root
perforating to apex
Dens Invaginatus
Dens in DenteTreatment –
restore the coronal pit
Drift
movement of erupted teeth
Migration
movement of unerupted teeth
Impacted Teeth -Descriptors
I. a. Full impaction –
II. b. Partial impaction - <
bony vs soft tissue
full eruption
skipped
Orientation
- Vertical
- Inverted
- Mesioangular
- Distoangular
- Horizontal
- Inverted Mesioangular
- Inverted Distoangular
Needed to evaluate
(2)
- prognosis
- surgical management
Problems with Supernumeraries and Impacted Teeth
(2)
- Affect eruption of normal complement of
teeth - Cystic degeneration of follicular
epithelium
enameloma
ectopic globule of enamel formation located on the root surface
aka enamel pearl
dentinoma (2)
may result from proliferation of connective tissue and hertwigs epithelial root sheath cells
epithelial remnants induce undifferentiated connective tissue cells to transform into odontoblasts that produce dentin
