Anomalies

Question 1

Which teeth are least likely to be missing?

Answer 1

first permanent molars
upper central incisors

Question 2

Which teeth are more likely to be missing?

Answer 2

mandibular premolars
maxillary lateral incisors

Question 3

List down conditions that are associated with hypodontia.

Answer 3

ectodermal dysplasia
down syndrome
cleft palate
hurler’s syndrome
inncontinentia pigmentii

Question 4

What is hypodontia?

Answer 4

missing teeth

Question 5

What is a complication that can occur with an upper lateral incisor is missing?

Answer 5

over-eruption of lower canines can be a restorative problem

Question 6

What are the complications that can arise due to hypodontia?

(5)

Answer 6

abnormal shape/form
spacing
submergence
deep overbite
reduced LFH

Question 7

What are the treatment options for hypodontia?

Answer 7

overdenture
partial denture
composite
porcelain veneers
fixed prostheses (i.e. implants)

Question 8

What is the incidence of hyperdontia/supernumerary between males and females?

Answer 8

male 2:1 female

Question 9

In which arch is supernumerary more common?

hyperdontia

Answer 9

maxilla

Question 10

Name a condition that has a high frequency of hyperdontia
supernumerary

Answer 10

cleidocranial dysplasia

Question 11

Name the 4 different types of supernumerary.

Answer 11

1. Conical (cone shaped)
2. Tuberculate (barrel shaped, has tubercles)
3. Supplemental (looks like tooth of normal series)
4. Odontome (irregular mass of dental hard tissue, compound or complex)

Question 12

What is the most common cause of delayed eruption of permanent incisor teeth?

Answer 12

presence of supernumerary teeth

Question 13

What is gemination?

Answer 13

one tooth splits into 2

double teeth

Question 14

What is fusion?

double teeth

Answer 14

2 teeth join to form 1

Question 15

What is the incidence (%) of short root?

Answer 15

2.5% in permanent maxillary incisors

15% of these children also have short roots on the canines and premolars

Question 16

What are the main types of amelogenesis imperfecta?

(4)

Answer 16

• hypoplastic
• hypocalcified
• hypomaturational
• mixed with taurodontism

Question 17

What are the environmental causes that can bring about environmental enamel hypoplasia?

(6)

Answer 17

• systemic
• nutritional
• metabolic e.g. Rhesus incompatability, liver disease
• infection e.g. measles
• trauma
• infection of primary tooth

Question 18

What is the incidence of amelogenesis imperfecta?

Answer 18

1:14,000

Question 19

What is the aetiology of amelogenesis imperfecta?

Answer 19

It is a hereditary condition that can be autosomal dominant, recessive and x-linked.

Question 20

How can amelogenesis imperfecta be diagnosed?

Answer 20

• family history
• generally affects both dentitions
• affects all teeth
• tooth size, structure, colour
• radiographs

Question 21

What is amelogenesis imperfecta of the hypoplastic type?

Answer 21

enamel crystals do not grow to the correct length

Question 22

What is amelogenesis imperfecta of the hypomineralised type?

Answer 22

crystallites fail to grow in thickness and width

Question 23

What is amelogenesis imperfecta of the hypomaturational type?

Answer 23

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

Question 24

What are the genes involved/mutated in amelogenesis imperfecta?

genes required for enamel formation

Answer 24

• amelogenin
• enamelin
• kallikrein 4

enamel extracellular matrix molecules

Question 25

What are the complications of amelogenesis imperfecta?

Answer 25

• sensitivity
• caries susceptibility
• poor aesthetics
• poor oral hygiene
• delayed eruption
• anterior open bite

Question 26

What is the management for amelogenesis imperfecta?

Answer 26

• preventive therapy
• composite veneers/composite wash
• fissure sealants
• metal onlays
• stainless steel crowns
• orthodontics

Question 27

List systemic disorders that are associated with enamel defects.

Answer 27

• epidermolysis bullosa
• incontinenta pigmenti
• downs syndrome
• prader-willi
• porphyria
• tuberous sclerosis
• pseudohypoparathyroidism
• hurler’s

Question 28

What is dentine dysplasia?

Answer 28

• normal crown morphology
• amber radiolucency
• pulpal obliteration
• short constricted roots

Question 29

What is odontodysplasia?

Answer 29

• localised arrest in tooth development
• thin layers of enamel and dentine
• large pulp chambers
• “ghost teeth”

Question 30

What are the 3 types of dentinogenesis imperfecta?

Answer 30

Type 1: osteogenesis imperfecta
Type 2: autosomal dominant
Type 3: Brandywine

Question 31

How can dentinogenesis imperfecta be diagnosed?

Answer 31

• appearance
• family history
• associated osteogenesis imperfecta
• both dentitions affected
• radiograph shows bulbous crowns, obliterated pulps (I & II)
• enamel loss

Question 32

What is an ocular feature of type I dentinogenesis imperfecta with osteogenesis imperfecta?

Answer 32

blue sclera

Question 33

What are the complications of dentinogenesis imperfecta?

Answer 33

• aesthetics
• caries susceptibility
• spontaneous abscess

Question 34

What is the management of dentinogenesis imperfecta?

Answer 34

• prevention
• composite veneers
• overdentures
• removable prostheses
• stainless steel crowns

Question 35

List systemic disorders that are associated with dentine defects.

Answer 35

• osteogenesis imperfecta
• ehlers-danlos syndrome
• brachio-skeletal genital syndrome
• rickets
• hypophosphatasia

Question 36

What are the causes of premature exfoliation of teeth?

(6)

Answer 36

• trauma
• following pulpotomy
• hypophosphatasia
• immunological deficiency e.g. cyclic neutropaenia
• chediak-higashi syndrome
• histiocytosis X

Question 37

What are the causes of delayed exfolation of teeth?

(5)

Answer 37

• infra-occlusion
• ‘double’ primary teeth
• hypodontia
• ectopic permanent successors
• following trauma

Question 38

Which tooth is most commonly infra-occluded?

Answer 38

lower first primary molar

due to a congenital abscence of premolar tooth

most would then exfoliate normally by age 11-12 years