Disorders Of Tooth Development

Question 1

What can be causes of variations of tooth development

Answer 1

Genetically determined
Local factor
Systemic factor

Question 2

What is hypotonia

Answer 2

Missing teeth- the failure of teeth to develop

Commonly upper 2s 5s and 8s

Question 3

What is anodontia

Answer 3

Complete lack of teeth

Question 4

What is hyperdontia?

Answer 4

Extra teeth- supernumeraries

Question 5

Are patients with missing primary teeth likely to have missing secondary teeth?

Answer 5

Yes. 30-50% with missing primary go on to have missing secondary

Question 6

What would appropriate treatment for hypotonia be?

Answer 6

Full or partial denture
Implants
Composite build ups if accompanied with small teeth to mask conical or mishapen appearance

Question 7

What is the ratio of hyperdontia male: female

Answer 7

2:1

Question 8

What are common presentations of hyperdontia

Answer 8

Mesiodens- supernumerary in between central incisors
Paramolars- supernumerary in molar region- can be buccal, lingual or palatal
Distomolar- supernumerary distal to 8s

5x more common maxillary

Question 9

What is megadontia

Answer 9

Larger teeth than normal

Seen in cases of pituitary gigantism

Question 10

What is microdontia?

Answer 10

Smaller than normal teeth

Commonly affects maxillary lateral incisors and 3rd molars

Question 11

What can be causes of disorders of root size?

Answer 11

Oriental background
Irradiation of jaws or chemo during root formation may cause shortened roots
Orthodontic tx 1mm reduction in root length per 1 years of tx

Question 12

What is gemination

Answer 12

Separation of single tooth germ to produce 2 separate teeth
Rare
Anteriors and deciduous most commonly affected

Question 13

What is fusion

Answer 13

Union of 2 separate adjacent tooth germs
Thought to be hereditary
More common in primary dentition

Question 14

What is concrescence

Answer 14

Joining of 2 teeth by cementum
Caused by trauma or crowding
Maxillary molars commonly affected

Question 15

What is dilaceration

Answer 15

Disruption of root formation
Caused by trauma to tooth germ during tooth development
Can impede tooth eruption

Question 16

What are invaginated teeth?

Answer 16

Infolding of palatal surface of crown- lined with enamel
Dens in dente
Appears as crown with deep pit in area of Cingulum
Radio graphically- pear shaped mass

Question 17

What tx is appropriate for invaginated teeth.

Answer 17

Fissure seal ASAP
Vitality test
RCT if pupal involvement.

Question 18

What are evaginated teeth?

Answer 18

Small tubercle non occlusal surface of premolar- central part of fissure system

Question 19

What is dens evaginatus

Answer 19

Talon cusp- horn projection of Cingular of maxillary incisor

Question 20

What is taurodontism

Answer 20

Affects molar teeth

Pulp chamber lengthened and shortened roots

Question 21

What are the two classifications of amelogenesis imperfecta?

Answer 21

Hypoplasia

Hypomineralisation

Question 22

Describe Hypoplasia

Answer 22

Deficient enamel matrix
Thinner enamel
Grooved or pitted
Glossy
Hard/ translucent

Question 23

Describe hypo mineralisation

Answer 23

Defect in mineralisation of enamel
Normal thickness but soft
Discoloured- brown/ yellow
Opaque/ chalky
Prone to caries

Question 24

What is management of amelogenesis imperfecta

Answer 24

Restorative tx
PMC s on 6s

Treat aesthetics and sensitivity

Question 25

What is dentinogenisis imperfecta?

Answer 25

Inherited disorder or dentine

Primary and permanent teeth affected
Teeth opalescent with greyish brown colour
Enamel prone to flake off due to poor adhesion
Pulpal exposure likely in deciduous

Question 26

What is congenital syphilis?

Answer 26

Caused by spirochete treponema pallidum found in the dental follicle
Transmitted via placenta
Associated with blindness, deafness and paralysis

Question 27

What 3 anomalies are associated with congenital syphiliis?

Answer 27

Hutchinson incisor- notch in incisal edge of upper 1s
Mulberry molars- 1st molars
Moon molars- round or dome shaped first molars

Question 28

What is enameloma- enamel pearls

Answer 28

Small spherical enamel projection on root surface
Caused by abnormal displacement of ameloblasts during formation
Maxillary molars commonly affected

Question 29

Rev fluorosis
Tetracycline staining
MIH

Answer 29

Revise above!!!!

Question 30

What variations can occur in the development of teeth

Answer 30

Variations of size, form and structure