Disorders of Tooth Formation

Question 1

In what way can a tooth be affected by disorders in formation?

Answer 1

1. Size
2. Form
3. Structure of tooth and its eruption

Question 2

What may cause disorders of tooth formation?

Answer 2

1. Genetically determined
2. Local or systemic factors
3. Both

Question 3

What is hypodontia?

Answer 3

Failure of development

Question 4

What teeth are most commonly affected by hypodontia?

Answer 4

1. 8s
2. 5s
3. Upper 2s

Question 5

What is anodontia?

Answer 5

Total lack of teeth

Question 6

Treatment for hypodontia?

Answer 6

1. Full or partial denture
2. Implants
3. Ortho treatment

Question 7

What is commonly seen alongside hypodontia and what treatment is advised?

Answer 7

Small teeth + composite to mask mis - shaped teeth

Question 8

What is hyperdontia?

Answer 8

Extra teeth

Question 9

What is hyperdontia also known as?

Answer 9

Supernumerary

Question 10

What is commonly seen in the permanent dentition when a disorder is present in the primary dentition?

Answer 10

The same disorder

Question 11

Extra teeth in the anterior maxilla in the midline or adjacent to the midline is referred to as what?

Answer 11

Mesiodens

Question 12

Extra teeth in molar regions are referred to as what?

Answer 12

1. Paramolars
2. Distomolars

Question 13

What is extra teeth sometimes associated with?

Answer 13

Syndromes such as cleidocranial dysplasia

Question 14

What is megadontia?

Answer 14

Teeth larger than usual

Question 15

When is megadontia commonly seen?

Answer 15

In cases of pituitary gigantism

Question 16

What is microdontia?

Answer 16

Teeth smaller than usual

Question 17

What teeth are most commonly affected by microdontia?

Answer 17

1. Maxillary lateral incisors
2. Third molars

Question 18

What is microdontia commonly associated with?

Answer 18

Various types of ectodermal dysplasia and down syndrome

Question 19

Why might someone have smaller roots?

Answer 19

1. Common in oriental background
2. Irradiation of jaws
3. Chemotherapy
4. Ortho treatment

Question 20

What origin are more likely to have larger roots?

Answer 20

African origin

Question 21

What is gemination?

Answer 21

Double teeth

Question 22

How does gemination happen?

Answer 22

Developmental separation of a single tooth germ to produce two separate teeth

Question 23

What is the cause of gemination?

Answer 23

Cause unknown

Question 24

What teeth are more commonly affected by gemination?

Answer 24

Anteriors and deciduous teeth

Question 25

What is fusion?

Answer 25

Double teeth

Question 26

How does fusion happen?

Answer 26

Union of two normally separated adjacent tooth germs

Question 27

What causes fusion?

Answer 27

Cause unknown but possibly hereditary

Question 28

How many canals are involved in fusion?

Answer 28

2 canals

Question 29

How many canals are involved in gemination?

Answer 29

1 canal

Question 30

What is concrescence?

Answer 30

The joining of two teeth in which one may be a supernumery by cementum

Question 31

What causes concrescence?

Answer 31

Thought to be trauma or crowding - root surfaces in close proximity

Question 32

What teeth are more commonly affected by concrescence?

Answer 32

Maxillary molars

Question 33

What is dilaceration?

Answer 33

Gross disruption of root formation

Question 34

What causes dilaceration?

Answer 34

Trauma to tooth germ during root development

Question 35

What happens to tooth if it has dilaceration?

Answer 35

Tooth forms at an angle

Question 36

What is the concern with dilaceration?

Answer 36

Can impede tooth eruption

Question 37

What is the treatment for tooth disorders within the primary dentition?

Answer 37

No treatment

Question 38

What is the treatment for tooth disorders within the permanent dentition?

Answer 38

Depends on 1. Space available 2. Morphology of pulp chambers and/or root canals 3. Degree of attachment between the two parts of the tooth

Question 39

What is an invaginated tooth/teeth?

Answer 39

Infolding on the palatal surface of the crown and lined with enamel

Question 40

How would you describe tooth tissue in invaginated teeth?

Answer 40

Normal tooth tissue but abnormal form

Question 41

What does dens in dente mean?

Answer 41

Tooth within a tooth

Question 42

How does invaginated teeth appear on radiograph?

Answer 42

Pear shaped mass of enamel in dentine surrounding a radiolucent area

Question 43

Are invaginated teeth common in primary teeth?

Answer 43

No

Question 44

What teeth are more likely to be invaginated?

Answer 44

Maxillary lateral incisors

Question 45

What is the treatment for invaginated teeth?

Answer 45

1. Fissure seal soon after eruption 2. Vitality test 3. Endodontic treatment if pulp involvement

Question 46

What is an evaginated tooth/teeth?

Answer 46

Small tubercule on the occlusal surface of the premolar in the central part of the fissure pattern

Question 47

What commonly happens to evaginated teeth?

Answer 47

Fractures off or worn down by normal wear

Question 48

Treatment for evaginated teeth?

Answer 48

1. Radiographs to assess for pulp horn involvement 2. Fissure seal 3. Removal of tubercule and sometimes pulpotomy

Question 49

What is a talon cusp?

Answer 49

Horn projection of the cingulum

Question 50

What teeth would you find a talon cusp?

Answer 50

Maxillary incisor teeth

Question 51

What treatment for talon cusp?

Answer 51

1. Fissure seal 2. Possible pulpotomy No treatment if no interference with occlusion

Question 52

What is taurodontism?

Answer 52

Bull teeth where the pulp chambers are enlarged vertically at the expense of the roots

Question 53

What teeth would you fine taurodontism?

Answer 53

Molar teeth

Question 54

What is amelogenesis?

Answer 54

Incomplete or defective formation of enamel

Question 55

How many types of amelogenesis are there?

Answer 55

12 - only 2 clinically

Question 56

What is hypoplasia?

Answer 56

Deficient enamel matrix

Question 57

What does hypoplasia look like?

Answer 57

1. Thin enamel 2. Grooved or pitted 3. Glossy 4. Hard and translucent

Question 58

What is hypomineralisation?

Answer 58

Defect in mineralisation of the enamel

Question 59

What does hypomineralisation look like?

Answer 59

1. Normal thickness but soft 2. Discoloured yellow/brown 3. Opaque and chalky 4. Prone to caries - weak 5. Prone to chips - weak

Question 60

What are the 2 types of amelogenesis?

Answer 60

1. Hypoplasia 2. Hypomineralisation

Question 61

What is dentinogenesis?

Answer 61

Inherited disorder of dentine

Question 62

How to teeth appear with dentinogenesis?

Answer 62

Opalescent witha grey/brown colour

Question 63

How to the roots appear in primary molars with dentinogenesis?

Answer 63

Short roots and pulp canal obliteration

Question 64

What is congenital syphilis?

Answer 64

Caused by spriochaete treponema pallidum found in the dental follicle

Question 65

How is congenital syphilis transmitted?

Answer 65

Via the placenta

Question 66

What are the 3 specific anomalies related to congenital syphilis?

Answer 66

1. Hutchinson's incisors 2. Mulberry molars 3. Moon Molars

Question 67

How does Hutchinson's incisors present?

Answer 67

1. Affects upper central incisors 2. Notch on incisal edge 3. Mesio - distal narrowing of incisal portion of the crown

Question 67

How does mulberry molars present?

Answer 67

1. Affects first permanent molars 2. Occlusal surface is rough and pitted 3. Compressed nodules instead of cusps 4. Looks like a raspberry

Question 68

How does moon molars present?

Answer 68

1. Affects first permanent molars 2. Round or dome shaped

Question 69

What is an enamel pearl/ enameloma?

Answer 69

Small spherical enamel projection on a root surface

Question 70

How do enamel pearls happen?

Answer 70

Abnormal displacement of ameloblasts during tooth formation

Question 71

Where does the enamel pearl appear?

Answer 71

Attached the cementum near root bifurcation area

Question 72

On a radiograph what is an enamel pearl often mistaken for?

Answer 72

Calculus