HHypodontia Flashcards
What is the definition of hypontia?
- Congenital absence of one or more teeth
What is the definition of anodontia?
- Complete absence of teeth
What is the definition of sever hypodontia ?
- 6 or more congenitally absent teeth
What is the prevalence of hypodontia?
- 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
In order what are the most likely congenitally absent teeth?
- 8s > L5s > U2s > U5s > lower incisors
What is the aetiology of hypodontia?
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
How does hypodontia cases tend to present?
- Delayed or asymmetric eruption
- Retained or infra occluded deciduous teeth
- Absent deciduous tooth
- Tooth form
What are some associated problems with hypodontia cases?
- 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
What are some potential problems with hypodontia cases?
- Spacing
- Drifting
- Over eruption
- Aesthetic impairment
- Functional problems
What is the hypodontia care pathway?
- 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
What is included in the assessment and planning of hypodontia cases?
- History
- Extra-oral examination
- Intra-oral examination
– Orthodontic aspects
– Restorative aspects - Investigations
- Problem list
- Definitive Plan
- Retention / maintenance
What investigations can be done?
- Study Models
- Planning models
– Kesling, diagnostic - Radiographs
- Photographs
- Conebeam CT
What are the treatment options for missing upper lateral incisors?
- Accept
- Restorative alone
- Orthodontics alone
- Combined orthodontic & restorative treatment
If pt wants to keep space open what txt options can be given in cases of missing upper laterals?
- Resin bonded bridge
- Implant (of age)
- Partial denture
- Conventional bridgework
- Autotransplantation
If pt wants space closed what are the two txt options for missing laterals?
- Simple closure
- Space close ‘plus’
Why might a RBB be chosen over cantilever bridge? What tooth is a good abutment?
- Better success rate
- Ideal abutment canine due to root length, crown dimensions, less shine through
What are some advantages of RBB?
- Relatively simple
- Do when young (complete treatment)
- Non-destructive
- Can look good
- Place on semi-permanent basis
What are the key differences between RBB vs implants?
- 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
What are some disadvantages to RBB for missing laterals?
- Failure rate
- Appearance sometimes not good, (try again, new materials)
- Orthodontic retention needs are high
- Predictable aesthetics?
What are some advantages to space closure plus option for missing laterals?
- No prosthesis – relatively low maintenance
- Good aesthetics with appropriate orthodontic and restorative techniques
- Can be done at an early age
What are the keys to successful management of hypodontia?
- 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
