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L7 dental developmental anomalies that affect the tooth as a unit (tooth…
L7 dental developmental anomalies that affect the tooth as a unit (tooth anomalies)
anomalies in number
Agenesis: congenital absence of one or more teeth
multiple agenesis or oligodontia
concept
The congenital absence of
6 or more teeth
Usually associated to:
anomalies in shape and size of the remaining teeth.
anomalies in other organs.
classificaiton
sectoral
Localized in a specific area of the oral cavity, generally in the same quadrant
Etiology: localized factors
dispersed
several quadrants are affected
E"ology: genetic factors or general environmental factors
aetiology (mostly environmental factors)
Localized:
Acting on a specific area of the dental lamina, preventing its development
Trauma, vascular, obstructive factors.
Generalized:
Infectious diseases during pregnancy or childhood
Endocrine alterations
Intoxication, radiation, chemotherapy during pregnancy
Genetic:
The most frequent cause of oligodontia
Associated to syndromes
others
many syndromes are associated to oligodontia.
the most common cases are ECTODERMAL DYSPLASIAS
a series of syndromes affec<ng the development of ectodermic structures skin, hair, nails, teeth, sweat glands, etc.
different hereditary patterns.
different clinical manifestations.
total agenesis or anodontia
concept
total absence of teeth.
extremely infrequent, as canines and first molars are phylogenetically very stable, and rarely present agenesis.
aetiology: same etiology as oligodontia but with
increased severity
isolated agenesis or hypodontia
DIFFERENTIAL DIAGNOSIS: retained tooth due to a delayed or altered eruption
DIAGNOSIS: Missing tooth after expected eruption + radiographs
Consequences:
Extrusion of opposing teeth.
Displacement of teeth, leading to functional problems.
Esthetic problems, especially when anterior teeth are
missing.
eitology
mostly genetic factors: inheritance pattern:
The genes involved have been identified only in a
small % of cases.
evolutionary factors are also involved.
concept
seldom occurrence in deciduous dentition
the most frequent dental anomaly permanent dentition: without counting 3d molars, whose absence is more frequent
the rest of the dentition is normal
the isolated absence of one or more teeth (1-5).
TREATMENT:
Implants
Orthodontic
Prostheses
Combinations of the above
hyperodontia
concept
Increased number of teeth: SUPERNUMERARY teeth
etiology (genetic)
excessive proliferation of the dental lamina, leading to an increased number of enamel organs
Gemination and complete dividing of the dental follicle
treatment
extraciton
aesthetic
classificaiton
shape
supplementary
normal morphology.
typically they are the mirror image of an adjacent tooth.
accessory
shape anomaly, usually conical or barrel-shaped
location
peridens
located in the premolar region
more frequent in the mandible
the term “peridens” is also used to name supernumerary teeth not located in the midline.
paramolar
located between the first
and second molars:
palatally
buccally
mesiodens
between central incisors
usually an accessory tooth (conical)
Consequences:
diastema between central incisors
misalignments
erupted or retained
distomolar
distal to the third molar.
4th molars.
more frequent in the maxilla.
can be fused to the third molar.
anomalies in attachments
gemination
AeNology:
mainly genetic factors
DIAGNOSIS:
The total number of teeth is:
• Normal (incomplete gemination)
• Increased by 1 (twinning)
concept
incomplete (macrodontia) or complete/twinning (supernumerary tooth).
consequences similar to those of fusion.
partial development of two teeth from a single tooth bud.
concrescence
concept
the connection of two or more teeth by cementum.
normal crown size and shape
hypercementosis is usually also present.
atiology:: traumatic factors due to lack of space
fusion
Consequences:
periodontal problems
high complexity if endodontic treatment is required
higher caries risk
esthetics are a true challenge for clinicians
etiology
Genetic factors
• Traumatic factors
concept
unilateral or bilateral.
total/partial.
two developing tooth buds become aSached, leading to a tooth that is larger than normal.
more frequent in the deciduous den;;on.
DIAGNOSIS:
the total number of teeth is decreased by 1
anomalies in size
microdontia (decreased size)
Relative generalized
microdontia
frequent
esthetic problems due to
diastemas
due to disproportion between bone and teeth
teeth have normal morphology
Localized microdontia
affecting one isolated tooth or a group of teeth
more common than generalized microdontia
usually associated to altered morphology, especially in lateral incisors (conical/screw-driver)
laterals/3dM/PM
True generalized
microdontia :
down’s syndrome
extremely rare
usually associated to pituitary dwarfism
teeth can have altered morphology
all teeth are smaller than normal
etiology
sometimes environmental factors
localized microdontia is associated to a hereditary
autosomal dominant pattern
mainly genetic factors
treatment: Aesthetic (to close diastemas and to prevent proximal caries)
macrodontia (increased size)
Relative generalized macrodontia
All teeth are normal or slightly larger than normal in size, inserted in a small maxilla or mandible
Localized macrodontia
More frequent in mandibular 3d M/I/C/2nd PM
Typically bilateral
Affecting one isolated tooth or a group of teeth
Usually due to a^achment anomalies (fusion or gemination)
True generalized macrodontia
rare
Associated to pituitary gigantism and other genetic alterations
All teeth are larger than normal
etiology: mainly genetic factors
treatment
Orthodontics, to treat crowding or malposition
Localized macrodontia doesn’t require treatment unless it is required for esthetic reasons
anomalies in shape
coronal
anomalies in incisors
isolated or associated to other pathology
affecting the external contour of the tooth
Hutchinson
concept
rare
permanent incisors and first molars
the deciduous dention is not affected
etiology: congenital syphilis (treponema pallidum)
classification
Deafness
Dental anomalies
Interstitial keratitis
accessory cusps
Atypical cusps located in any dental group:
classification
anteriors
Frequent: lingula/palatal/maxilla
Less frequent: buccal
premolars:Buccal Lingual/palatal Occlusal
molars
Buccal:
paramolar tubercle
Palatal:
Carabelli
What does their existence involve from a clinical point of view?
Pulp pathology: presence of a pulp horn
Increased caries risk: grooves and fissures at the junction with the crown
A particular variant is “dens evaginatus”, located in the central sulcus or lingual cusp slope of the buccal cusp of permanent molars and premolars
radicular
ectopic enamel
enamel pearls
may contain dentin or pulp
periodontal problems
spheres of enamel on the roots of multirooted teeth
cervical extensions of enamel
projections of enamel towards the cervical portion at the furcation of multirooted teeth
more frequent on buccal surfaces than on lingual ones
especially mandibular molars
sometimes covered partially in cementum
periodontal problems
supernumerary
more frequent in the mandible,
especially 3d molar.
normal in size and shape or as an appendix.
abnormal curvatures
Aetiology:
• Trauma or mechanical obstacles during dental development
LACERATION: curved roots in relation to the crown
total
taurodontism
Etiology: mainly genetic factors
TREATMENT: not required
Diagnosis: Radiographic
(clinically, a taurodont appears as a normal tooth)
concept
the furcation is displaced apically.
usually the cemento-enamel constriction is
not present.
the size of the pulp chamber is increased in
an occluso-apical direction.
the most commonly affected teeth are permanent molars
it may be associated to syndromes such as amelogenesis imperfecta, supernumerary teeth, microdon;a, dens invaginatus, etc
dens invaginatus
concept
external surface of the tooth folds inwards (enamel, dentin, sometimes even pulp)
more frequent in the maxilla, especially lateral incisors (60% cases)
frequent in supernumerary teeth
unilateral or bilateral
etiology
genetic factors
•mechanical factors that exert pressure on
the tooth bud
conical
Etiology: mainly genetic factors
TREATMENT:
porcelain veneers
Esthetic
• composite resins
concept
isolated or associated to other anomalies or syndromes
the crown and the root are cone shaped, joined at the bases
the most frequent anomaly
most commonly affecting
: • maxillary lateral incisors
• bilaterally
• supernumerary teeth
• microdontia