Disorders of tooth formation Flashcards
what is hypodontia?
failure of development
what is anodontia?
total lack of teeth
what is hyperdentia?
supernumeraries
if there are missing primary teeth what are the chances of the perm teeth are missing?
30-50%
Tx of missing teeth?
full and partial dentures
implants
what do missing teeth often present with?
small teeth
what is the incidence of supernumerary teeth?
more in perm dentition
more in males
if in primary - 30-50% chance in secondary
what is the name of a supernumerary teeth in the anterior maxilla?
mesiodens
what are the names of supernumeraries in the molars?
paramolars/distomolars
are supernumeraries more common in the maxilla or mandible?
5:1 maxilla : mandible
supernumeraries usually idiopathic, may be associated with?
cleidocondrial dysplasia
what is megadontia?
teeth larger than normal
rare
pituitary gigantism
all teeth are rarer
what is microdontia?
teeth are smaller than normal
maxl laterals and 3rd molars
max laterals - peg shaped
more common in females
what background are shorter roots more common in ?
oriental background
what background are longer roots more common in?
african background
how might someone have smaller jaws?
irradiation of jaws/chemo during root formation
what are double teeth/germination?
developmental separation of a single tooth germ = 2 separate teeh
cause unknown
rare
anterior/deciduous are most affected
what are double teeth/fusion?
union of 2 separate adjacent germs
more common in primary
what is concrescence?
joining of 2 teeth by cementum - one could be supernumerary
what is concrescence caused by?
trauma/crowding - root surfaces in close proximity
maxillary molars commonly affected
what is dilaceration?
gross disruption of root formation trauma to tooth germ during root development remainder forms at an angle occurs anywhere on root surface discovered on radiograph can impede tooth eruption
what is invagination?
infolding of palatal surface of crown and lined with enamel, sometimes extending into root - dilaceration
normal/malformed crown with deep pit or crevice in area of cingulum
tooth in tooth
pear shaped enamel mass in dentine surrounded by a radiolucency
who is invagination common in?
males
chinese
maxillary laterals
how to tx invagination?
FS after eruption
vitality test/radiograph
endo if pulpal involvement
what is evagination?
small tubercle on an occlusal surface of premolar in centre of fissure pattern
who is evagination more common in?
chinese
what is the tx of evagination?
fractures off/wears down
Xray - pulpal involvement?
what is a talon cusp?
horn like projection of cingulum of max incisors - may reach incisal contact with lower anteriors
how to tx a talon cusp
FS margins poss pulpectomy no tx if no occlusal interference radiograph - pulp involvement? remove tubercle and pulpotomy if required
what is tauorodontism?
bull like teeth - molars have vertically enlarged pulp chambers @ expense of roots
what is amelogenesis imperfecta?
generalised enamel defects affecting all teeth of the primary and permanent dentition
genetic
what is hypoplasia?
deficient enamel matrix
thinner enamel, grooves/pits, glossy, hard or translucent
what is hypomineralisation?
defect in mineralisation normal thickness but very soft discoloured yellow/brown opaque and chalky prone to caries - weak enamel chips easy
how do you treat localised defects?
crowns etc
how do you treat generalised defects?
treat aesthetics, sensitivity, poor oh and staining
what is dentinogenesis imperfecta?
may or may not be associated with osteogenesis imperfecta primary and secondary opalescent grey/brown enamel flakes off bc poor adhesion deciduous - pulpal exposures likely perm less severely affected
what is congenital syphilis?
treponema pallidium in dental follicle
transmitted via placenta associated with blindness deafness and paralysis
what are the 3 types of tooth abnormalities as a result of syphilis?
- hutchinsons incisors
- mulbery molars
- moons molars
what are hutchinsons incisors?
upper centrals with a notch at the incisal edge
mesiodistal narrowing of incisal portioj = ant open bite
what are mulberry molars?
1st perm molars
occlusal surface is rough and pittd
compressed nodules - no cusps
what are moons molars?
1st perm molars
round/dome shaped
what is enamel pearl?
small spherical projection on root surface
abnormal displacement of ameloblasts during tooth formation
max molars commonly affected
attached to cementum near root formation
often mistook for calculus
