Disorders of tooth formation

Question 1

what is hypodontia?

Answer 1

failure of development

Question 2

what is anodontia?

Answer 2

total lack of teeth

Question 3

what is hyperdentia?

Answer 3

supernumeraries

Question 4

if there are missing primary teeth what are the chances of the perm teeth are missing?

Answer 4

30-50%

Question 5

Tx of missing teeth?

Answer 5

full and partial dentures

implants

Question 6

what do missing teeth often present with?

Answer 6

small teeth

Question 7

what is the incidence of supernumerary teeth?

Answer 7

more in perm dentition
more in males
if in primary - 30-50% chance in secondary

Question 8

what is the name of a supernumerary teeth in the anterior maxilla?

Answer 8

mesiodens

Question 9

what are the names of supernumeraries in the molars?

Answer 9

paramolars/distomolars

Question 10

are supernumeraries more common in the maxilla or mandible?

Answer 10

5:1 maxilla : mandible

Question 11

supernumeraries usually idiopathic, may be associated with?

Answer 11

cleidocondrial dysplasia

Question 12

what is megadontia?

Answer 12

teeth larger than normal
rare
pituitary gigantism
all teeth are rarer

Question 13

what is microdontia?

Answer 13

teeth are smaller than normal
maxl laterals and 3rd molars
max laterals - peg shaped
more common in females

Question 14

what background are shorter roots more common in ?

Answer 14

oriental background

Question 15

what background are longer roots more common in?

Answer 15

african background

Question 16

how might someone have smaller jaws?

Answer 16

irradiation of jaws/chemo during root formation

Question 17

what are double teeth/germination?

Answer 17

developmental separation of a single tooth germ = 2 separate teeh
cause unknown
rare
anterior/deciduous are most affected

Question 18

what are double teeth/fusion?

Answer 18

union of 2 separate adjacent germs

more common in primary

Question 19

what is concrescence?

Answer 19

joining of 2 teeth by cementum - one could be supernumerary

Question 20

what is concrescence caused by?

Answer 20

trauma/crowding - root surfaces in close proximity

maxillary molars commonly affected

Question 21

what is dilaceration?

Answer 21

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

Question 22

what is invagination?

Answer 22

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

Question 23

who is invagination common in?

Answer 23

males
chinese
maxillary laterals

Question 24

how to tx invagination?

Answer 24

FS after eruption
vitality test/radiograph
endo if pulpal involvement

Question 25

what is evagination?

Answer 25

small tubercle on an occlusal surface of premolar in centre of fissure pattern

Question 26

who is evagination more common in?

Answer 26

chinese

Question 27

what is the tx of evagination?

Answer 27

fractures off/wears down | Xray - pulpal involvement?

Question 28

what is a talon cusp?

Answer 28

horn like projection of cingulum of max incisors - may reach incisal contact with lower anteriors

Question 29

how to tx a talon cusp

Answer 29

``` FS margins poss pulpectomy no tx if no occlusal interference radiograph - pulp involvement? remove tubercle and pulpotomy if required ```

Question 30

what is tauorodontism?

Answer 30

bull like teeth - molars have vertically enlarged pulp chambers @ expense of roots

Question 31

what is amelogenesis imperfecta?

Answer 31

generalised enamel defects affecting all teeth of the primary and permanent dentition genetic

Question 32

what is hypoplasia?

Answer 32

deficient enamel matrix | thinner enamel, grooves/pits, glossy, hard or translucent

Question 33

what is hypomineralisation?

Answer 33

``` defect in mineralisation normal thickness but very soft discoloured yellow/brown opaque and chalky prone to caries - weak enamel chips easy ```

Question 34

how do you treat localised defects?

Answer 34

crowns etc

Question 35

how do you treat generalised defects?

Answer 35

treat aesthetics, sensitivity, poor oh and staining

Question 36

what is dentinogenesis imperfecta?

Answer 36

``` 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 ```

Question 37

what is congenital syphilis?

Answer 37

treponema pallidium in dental follicle | transmitted via placenta associated with blindness deafness and paralysis

Question 38

what are the 3 types of tooth abnormalities as a result of syphilis?

Answer 38

1. hutchinsons incisors 2. mulbery molars 3. moons molars

Question 39

what are hutchinsons incisors?

Answer 39

upper centrals with a notch at the incisal edge | mesiodistal narrowing of incisal portioj = ant open bite

Question 40

what are mulberry molars?

Answer 40

1st perm molars occlusal surface is rough and pittd compressed nodules - no cusps

Question 41

what are moons molars?

Answer 41

1st perm molars | round/dome shaped

Question 42

what is enamel pearl?

Answer 42

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