hypodontia

Question 1

What is hypodontia

Answer 1

Congenital absence of one or more teeth

Question 2

What is anodontia

Answer 2

Complete absence of teeth

Question 3

What are the classifications of hypodontia

Answer 3

Mild- 1 or 2 missing teeth

Moderate- 3 to 6 missing teeth

Severe/oligodontia- more than 6 missing

Anodontia- complete absence of teth in 1 or more dentitions

Question 4

Whgat is the most common missing tooth in the primary dentition

Answer 4

primary Lateral incisors

Question 5

What is the most common missing tooth in the perment dentition

Answer 5

Lower second premolars and upper lateral incisors

Question 6

What is non-syndromic hypodontia

Answer 6

Mutations in at least 3 genes associated with missing teeth in non-syndromic hypodontia

Familial

Sporadic

Question 7

What is syndromic hypodontia

Answer 7

> 100 craniofacial syndromes associated with hypodontia:

• Cleft lip and palate
• Anhydrotic ectodermal dysplasia
• Down syndrome

Question 8

What is the presentation of hypodontia

Answer 8

Delayed or asymmetric eruption

Retained or infra-occluded deciduous teeth

Absent deciduous tooth

Tooth form

commonly associated with reduced lower face height and a deep overbite

Question 9

What can hypodontia do to the alveolar bone

Answer 9

May result in atrophic alveolar ridges or local bone deficit due to the underdevelopment of the alveolus in the abscence of teth

Question 10

What dental problems are associated with hypodontia

Answer 10

Microdontia

Malforamtion of other teeth

Short root anomaly

Impaction

Ectopic upper canine

Impaction

Delayed formation/eruption of other teeth

Crowding/malposition of other teeth

Maxillary canine/first premolar transposition

Taurodontism

Enamel hypoplasia

Altered craniofacial growth

Question 11

What is the hypodontia care pathway

Answer 11

GDP recognition

Referral to Specialist Orthodontist

In GDH:
– Initial assessment in Orthodontics and allocate when appropriate to Hypodontia Clinic

Question 12

What investigations are there for hypodontia

Answer 12

Study Models

Planning models
– Kesling, diagnostic

Radiographs

Photographs

Conebeam CT

Question 13

What is a kesling model

Answer 13

a visual aid to communication between the clinician and the patient at the treatment planning stage

Question 14

What are the Tx options for hypodontia

Answer 14

1. Accept
2. Management of retained primary teeth, maintenance or extractions
3. Restorative camoflauge to later shape and size of exsisting teeth
4. ortho Tx
5. Tooth replacement

Question 15

What could the Tx be from a Multi disciplinary team for a pt with missing upper laterals

Answer 15

Depends on if space open or closed

Space closed:
-simple closure
-space close ‘plus’

Space open:
-RBB
-Implant
-partial denture

Question 16

When creating a Tx plan what must you consider

Answer 16

1. Satisfies expected aesthetic objectives
2. Least invasive
3. Satisfies expected functional objectives
   – Immediate
   – Long term (65 years +)

Question 17

When managing retained primary teeth what are the choices and what influences them

Answer 17

Choice between maintaining or extraction to enable spontaneous or active closure

Choice is influenced on: number/location of teeth, health of prim. tooth, position of prim. tooth, spacing, crowding and inter arch relationship

Question 18

When would you retain a primary tooth and why

Answer 18

if it has good coronal health and adequate root length

They act as natural space maintainers and reduces alveolar bone resorption preserving soft tissue architecture

Question 19

When planning for the retainment of a prim. tooth what should also be planned

Answer 19

a long term plan that also involves the managment of the eventual tooth loss

Involving a Tx plan that positions adjacent teeth in a position to facilitate tooth replacement

Question 20

When managing missing upper lateral incisors when would you want to keep the space open

Answer 20

Class III skeletal pattern

No crowding or spacing

Class I buccal segment

Unfavorable canine colour and morphology

hypodontia or teeth of poor prgonosis in same quadrant

Question 21

When managing missing upper lateral incisors when would you want to keep the space closed

Answer 21

class II skeletal pattern

Crowding

Class II buccal segment

Favourable canine colour and morphology

Pt does not want prosthesis

Question 22

What are the advantages of a RBB

Answer 22

Relatively simple
Do when young (complete treatment)

Non-destructive

Can look good

Place on semi-permanent basis

Better success rate than cantilever bridges

Question 23

What is an ideal abutment tooth for a RBB

Answer 23

Canine
-Good root length
-Good Crown dimensions

Question 24

What are thet disadvantages of a RBB

Answer 24

Failure rate

Apperance sometimes not good

Ortho retention needs are high

Predictable aesthetics

Question 25

What are key differences between RBB and implants

Answer 25

Can’t do implant till growth has ceased –21+

Need minimum 7mm space

Root separation

Often need bone graft
Technically very demanding in aesthetic zone

Significant extra time to do

Significant cost

Question 26

What are the advantages of space closure plus

Answer 26

No prosthesis – relatively low maintenance

Good aesthetics with appropriate orthodontic and restorative techniques

Can be done at an early age

Question 27

What are the keys to a successful management of hypodontia

Answer 27

Inter disciplinary team

Joint assessment and Tx planning with precise aims

Joint collab at transitional stages of Tx

Follow up of treated cases