dental anomalies

Question 1

is hypodontia more common in the deciduous or permanent dentition

Answer 1

permanent (6%)
very rare in deciduous dentition (0.5%)

Question 2

what is the most commonly missing teeth in the permanent dentition

Answer 2

mandibular premolars and maxillary lateral incisors
if tooth missing , likely to be last in series e.g 3rd molar, 2nd premolar, lateral incisor

Question 3

what are the least likely teeth to be missing in the permanent dentition

Answer 3

first permanent molars and upper central incisors

Question 4

conditions associated with hypodontia

Answer 4

ectodermal dysplasia
downs syndrome
CLP

hurlers syndrome
incontinentia pigmentii

Question 5

what are the 4 types of supernumerary teeth

Answer 5

conical - cone shaped
tuberculate - barrel shape with tubercles, tend to come in pairs
supplemental - mimics normal tooth
odontome - irregular mass of enamel and dentine

Question 6

what is the most common cause of delayed eruption of permanent incisors

Answer 6

supernumerary blocking path
most often tuberculate

Question 7

most common presentation of microdontia

Answer 7

peg lateral incisor

Question 8

what are the two types of ‘double teeth’

Answer 8

gemination - one tooth split into two
fusion - two teeth joined to form one
hard to visually tell apart

Question 9

taurodontism

Answer 9

flame shaped pulp
teeth themselves look normal , issue comes with plp exposure

Question 10

dens in dente

Answer 10

‘tooth wthin a tooth’
enamel folds into dentine during development
If seen and no caries present, immediately seal all exposed dentine to prevent bacterial ingress

Question 11

what are the most common causes of short root anomalies

Answer 11

radiotherapy
dentine dysplasia
accessory roots

Question 12

what speciality are short root anomalies most significant

Answer 12

orthodontics
maxillary permanent incisors most commonly affected

Question 13

what are the 4 main forms of amelogenesis imperfecta

Answer 13

hypoplastic
hypocalcified
hypomaturational
mixed

Question 14

environmental vs localised enamel hypoplasia

Answer 14

environmental - systemic cause e.g infection, kidney/ liver failure, nutritional problems
localised - trauma, infection of primary tooth causing problems with successor

Question 15

name 3 potential causes for generalised environmental enamel defects
Think fluorosis, MIH etc

Answer 15

pre natal - rubella, cardiac and kidney disease
neo natal - pre maturity, meningitis
post natal - measles, chicken pox, TB, pneumonia, deficiency of vits A, C and D, long term health issues e.g organ failure or heart disease

Question 16

is amelogenesis imperefcta an environmental or hereditary disease

Answer 16

hereditary
usually evidence of familial inheritance
usually no associated systemic disorders

Question 17

how can amelogenesis imperfecta be identified on a radiograph

Answer 17

no obvious radiolucency change between enamel and dentine

Question 18

hypoplsatic amelogenesis imperfecta

Answer 18

enamel crystals dont grow to correct length

Question 19

hypomineralised (hypocalcified) amelogenesis imperfecta

Answer 19

crystallites fail to grow to correct thickness and width

Question 20

hypomaturational amelogenesis imperfecta

Answer 20

crystals grow incompletely in thickness and width but to normal length with incomplete mineralisation