hypodontia Flashcards
What is hypodontia
Congenital absence of one or more teeth
What is anodontia
Complete absence of teeth
What are the classifications of hypodontia
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
Whgat is the most common missing tooth in the primary dentition
primary Lateral incisors
What is the most common missing tooth in the perment dentition
Lower second premolars and upper lateral incisors
What is non-syndromic hypodontia
Mutations in at least 3 genes associated with missing teeth in non-syndromic hypodontia
Familial
Sporadic
What is syndromic hypodontia
> 100 craniofacial syndromes associated with hypodontia:
- Cleft lip and palate
- Anhydrotic ectodermal dysplasia
- Down syndrome
What is the presentation of hypodontia
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
What can hypodontia do to the alveolar bone
May result in atrophic alveolar ridges or local bone deficit due to the underdevelopment of the alveolus in the abscence of teth
What dental problems are associated with hypodontia
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
What is the hypodontia care pathway
GDP recognition
Referral to Specialist Orthodontist
In GDH:
– Initial assessment in Orthodontics and allocate when appropriate to Hypodontia Clinic
What investigations are there for hypodontia
Study Models
Planning models
– Kesling, diagnostic
Radiographs
Photographs
Conebeam CT
What is a kesling model
a visual aid to communication between the clinician and the patient at the treatment planning stage
What are the Tx options for hypodontia
- Accept
- Management of retained primary teeth, maintenance or extractions
- Restorative camoflauge to later shape and size of exsisting teeth
- ortho Tx
- Tooth replacement
What could the Tx be from a Multi disciplinary team for a pt with missing upper laterals
Depends on if space open or closed
Space closed:
-simple closure
-space close ‘plus’
Space open:
-RBB
-Implant
-partial denture
When creating a Tx plan what must you consider
- Satisfies expected aesthetic objectives
- Least invasive
- Satisfies expected functional objectives
– Immediate
– Long term (65 years +)
When managing retained primary teeth what are the choices and what influences them
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
When would you retain a primary tooth and why
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
When planning for the retainment of a prim. tooth what should also be planned
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
When managing missing upper lateral incisors when would you want to keep the space open
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
When managing missing upper lateral incisors when would you want to keep the space closed
class II skeletal pattern
Crowding
Class II buccal segment
Favourable canine colour and morphology
Pt does not want prosthesis
What are the advantages of a RBB
Relatively simple
Do when young (complete treatment)
Non-destructive
Can look good
Place on semi-permanent basis
Better success rate than cantilever bridges
What is an ideal abutment tooth for a RBB
Canine
-Good root length
-Good Crown dimensions
What are thet disadvantages of a RBB
Failure rate
Apperance sometimes not good
Ortho retention needs are high
Predictable aesthetics
What are key differences between RBB and implants
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
What are the advantages of space closure plus
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 a successful management of hypodontia
Inter disciplinary team
Joint assessment and Tx planning with precise aims
Joint collab at transitional stages of Tx
Follow up of treated cases
