Dental Anomalies

Question 1

give 3 conditions to do with anomalies of the number of teeth

Answer 1

• hyperdontia
• hypondontia
• retained primary teeth

Question 2

what is hyperdontia?

Answer 2

when you have supernumerary teeth

Question 3

what 3 conditions may hyperdontia be associated with?

Answer 3

• cleidocranial dysotosis
• gardener syndrome
• cleft lip and palate

Question 4

what is hyperdontia Mesiodens?

Answer 4

a supernumerary tooth present in the midline between the two central incisors

Question 5

4 indications of Mesiodens.

Answer 5

• malocclusion
• food impaction
• poor aesthetic
• cyst formation

Question 6

what is hypodontia? aetiology

Answer 6

absence of the teeth

• obstruction of the dental lamina
• lack of space for development
• failure of initiation of the mesenchyme

Question 7

which teeth are most affected by hypodontia?

Answer 7

permanent teeth
3rd molar
2nd mandibular premolar
max lateral incisor

Question 8

define oligodontia

Answer 8

more than 6 teeth missing

Question 9

define anodontia

Answer 9

complete loss of dentition

Question 10

what problem can a retained deciduous tooth cause?

Answer 10

it can prevent successor eruption of the permanent tooth

Question 11

what is fusion?

Answer 11

when a supernumerary tooth is fused

Question 12

what is gemination?

Answer 12

when a tooth begins to separate into two

Question 13

what are the two forms of size anomalies?

Answer 13

macrodontia
microdontia

Question 14

which tooth is likely to have macrodontia

Answer 14

most likely maxillary central incisors

Question 15

which 3 conditions may be associated with macrodontia?

Answer 15

pituitary gigantism
craniofacial dystosis
congenital facial hemihypertrophy

Question 16

which tooth is likely to have microdontia?

Answer 16

maxillary lateral incisor

Question 17

what 2 conditions can be associated with microdontia?

Answer 17

downs syndrome
ectodermal dysplasia

Question 18

give 4 anomalies in which teeth can have different shape.

Answer 18

• gemination
• fusion
• dens evagintus - enamel pearl
• dens invagintus - infolding of enamel and dentine

Question 19

what is dens evaginatus?

Answer 19

enamel tubercule extends from occlusal surface

Question 20

give 3 anomalies of tooth structure.

Answer 20

• amelogenesis imperfecta
• dentinogenesis imperfecta
• molar-incisor hypo mineralisation

Question 21

what is the aetiology of amelogenesis imperfecta?

Answer 21

genetic mutation in matrix protein coding genes

Question 22

3 forms of oral presentation from amelogenesis imperfecta. describe them.

Answer 22

hypoplastic
- pitted discoloured enamel
- prone to caries and attrition
- open bite

hypocalcification and hypomaturation
- discoloured soft enamel
- easy to chip and break under mastication

Question 23

what are the types of dentinogenesis imperfecta? describe what mutation causes them.

Answer 23

type 1
- associated with osteogenesis imperfecta
- mutation in COL1A and COL2A

type 2
- more common
- mutation in gene encoding DSPP

type 3
- familial
- mutation in gene encoding DSPP

Question 24

state and describe the two types of dental dysplasia.

Answer 24

type 1
- crown is normal
- both dentitions affected
- roots are sharp
- incomplete pulp obliteration

• extreme tooth mobility and premature exfoliation

type 2
- primary dentition is mostly affected
- permanent have thinner roots
- may have pulpal stones

Question 25

what is Molar Incisor Hypomineralisation?

Answer 25

enamel is very soft
- chips and discolours
- prone to caries

Question 26

give 2 systemic syndromes associated with dental anomalies.

Answer 26

• ectodermal dysplasia
• cleidocranial dysostosis

Question 27

define ectodermal dysplasia. aetiology and presentations

Answer 27

primary defect in the development of 2+ tissues derived from embryonic ectoderm

aetiology
- inherited
- involves skin and teeth

presentations
- soft, discoloured enamel
- small, peg shaped teeth
- roots - abnormal shape
- missing teeth
- xerostomia
- underdeveloped alveolar bone

Question 28

describe what cleidocranial dysostosis is. aetiology and presentations.

Answer 28

aetiology
- mutation of RUNX-2

presentations
- underdeveloped or absent collar bone
- late closure of skull fontanelles
- high vaulted palate
- may have clefts
- short stature
- osteopenia and osteoporosis
- hearing loss