HHypodontia

Question 1

What is the definition of hypontia?

Answer 1

• Congenital absence of one or more teeth

Question 2

What is the definition of anodontia?

Answer 2

• Complete absence of teeth

Question 3

What is the definition of sever hypodontia ?

Answer 3

• 6 or more congenitally absent teeth

Question 4

What is the prevalence of hypodontia?

Answer 4

• Approx 6% of pop excluding 8s
• More F:M 6:4%
• 0.9% in primary dentition
• Missing upper lateral inisiors 1-2% of pop
• Ass with ectopic canines
• Most hypodontia cases will have misses U2s

Question 5

In order what are the most likely congenitally absent teeth?

Answer 5

• 8s > L5s > U2s > U5s > lower incisors

Question 6

What is the aetiology of hypodontia?

Answer 6

Non syndromic
- Mutations in 3or more genes ass with missing teeth
- Familial
- Sporadic

Syndromic
- >100 craniofacial syndromes ass with hypodontia
- Cleft lip and palate
- Anhydrotic ectodermal dysplasia

Environmental
- Trauma
- Radiotherapy /chemotehrapy

Question 7

How does hypodontia cases tend to present?

Answer 7

• Delayed or asymmetric eruption
• Retained or infra occluded deciduous teeth
• Absent deciduous tooth
• Tooth form

Question 8

What are some associated problems with hypodontia cases?

Answer 8

• Microdontia
• Malformation of other teeth
• Short root anomaly
• Impaction
• Delayed formation and/or delayed eruption other teeth
• Crowding and/or malposition of other teeth
• Maxillary canine/first premolar transposition
• Taurodontism
• Enamel hypoplasia
• Altered craniofacial growth

Question 9

What are some potential problems with hypodontia cases?

Answer 9

• Spacing
• Drifting
• Over eruption
• Aesthetic impairment
• Functional problems

Question 10

What is the hypodontia care pathway?

Answer 10

• GDP recognition
• Referral to specialist orthodontist
• Referall to GDH ortho speicialise where initila assessment and allocation when appropriate to hypodontia clinic for ortho and restorative input

Key to successful management

Question 11

What is included in the assessment and planning of hypodontia cases?

Answer 11

• History
• Extra-oral examination
• Intra-oral examination
  – Orthodontic aspects
  – Restorative aspects
• Investigations
• Problem list
• Definitive Plan
• Retention / maintenance

Question 12

What investigations can be done?

Answer 12

• Study Models
• Planning models
  – Kesling, diagnostic
• Radiographs
• Photographs
• Conebeam CT

Question 13

What are the treatment options for missing upper lateral incisors?

Answer 13

• Accept
• Restorative alone
• Orthodontics alone
• Combined orthodontic & restorative treatment

Question 14

If pt wants to keep space open what txt options can be given in cases of missing upper laterals?

Answer 14

• Resin bonded bridge
• Implant (of age)
• Partial denture
• Conventional bridgework
• Autotransplantation

Question 15

If pt wants space closed what are the two txt options for missing laterals?

Answer 15

• Simple closure
• Space close ‘plus’

Question 16

Why might a RBB be chosen over cantilever bridge? What tooth is a good abutment?

Answer 16

• Better success rate
• Ideal abutment canine due to root length, crown dimensions, less shine through

Question 17

What are some advantages of RBB?

Answer 17

• Relatively simple
• Do when young (complete treatment)
• Non-destructive
• Can look good
• Place on semi-permanent basis

Question 18

What are the key differences between RBB vs implants?

Answer 18

• Can’t do implant till growth has ceased – now 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 19

What are some disadvantages to RBB for missing laterals?

Answer 19

• Failure rate
• Appearance sometimes not good, (try again, new materials)
• Orthodontic retention needs are high
• Predictable aesthetics?

Question 20

What are some advantages to space closure plus option for missing laterals?

Answer 20

• No prosthesis – relatively low maintenance
• Good aesthetics with appropriate orthodontic and restorative techniques
• Can be done at an early age

Question 21

What are the keys to successful management of hypodontia?

Answer 21

• Inter-disciplinary team (joint appointment)
• Joint assessment and treatment planning with precise aims
• Joint collaboration at transitional stages of treatment
• Follow up of treated cases