Edentulous Ridges Flashcards
What health outcomes are associated with edentulism?
People who are edentulous often attend the dentist less often, have poorer diet, have shorter life expectancy, and have increased cardiovascular disease risk
Who is more at risk of becoming edentulous?
Older groups
Increased in people with <9 years of schooling
Increased in patients eligible for the public dental services
Increased in people living in remote/rural areas
F > M ratio
19% of patients >65 are fully edentulous
What is the trend of prevalence of edentulism?
Projections stated that by 2021 rate 2.7 - 3% and by 2041 0.4 - 1%
Average tooth loss per person was 10.8
So it is decreasing
What are the classes of bone loss?
Class 1 - Tooth present no bone loss
Class 2 - Immediate tooth loss no bone loss
Class 3 - Rounding of the boney ridge
Class 4 - Knife edge ridge - good height but poor width
Class 5 - Flat ridge height and width loss
Class 6 - Resorption down to basal bone
How is bone typically lost? (direction)
From buccal to lingual
How do complete dentures affect chewing forces with time?
After 5 years there is 75% reduction in chewing forces and after 15 years 97%
What problems are common in patients with complete dentures?
Comfort/sore spots
Aesthetics
Phonetics
Swallowing
Nausea
Loss of taste
Poorer quality of life
What landmarks are used in the Misch-Judy classification?
Sextants divided by mental foramen and bounded by the retromolar pad.
Maxilla anterior sextant is bound by second premolars through to second molars
This is because their is definitive change between these areas
How are edentulous arches classified by Misch-Judy?
Type 1, 2 and 3 each having subclasses of A B C D E F G H
Type 1 = Bone similar in all sextants. A = abundant bone, B = Abundant bone but only good for narrow implants, C = Good height poor width so onlay grafting needed, D - H = Poor height and width so major bone grafting needed.
Type 2 = Difference between posterior and anterior sextants. Sinus pneumatisation in maxilla and resorption of the posterior mandible.
Type 3 = Anterior sextants similar bone volumes and posterior sextants different. Right and left posterior differ and Grafting requirements are different between areas
What affects the amount of bone loss?
The cause of tooth loss
Existing diseases pre-extraction
Genetics
Position
Why is the bone ridge classification important?
Maxillary sinus is present above the maxillary molars meaning bone ridge is compromised in some people in that area.
Anterior maxilla tends to hold onto bone height but loses bone width.
Mandible posterior areas lose bone level quickly which impacts implants severely
What strategies are available for implant retained prostheses?
All on 4 or all on 6.
Replacing every missing tooth with implants
What does strategy of edenulous treatment depend on?
Amount of available bone
Choice of material for super structure
Proximity of sinus and pneumatisation
Proximity of neurovascular bundles
Previous history of periodontal diseases
Finances of patient
When is all on 4 and all on 6 used?
6 implants are indicated for full arch fixed prosthesis in the maxilla
4 implants are sufficient in the mandible
What are the advantages of using all on 4/6?
Tilted implants have made the all on 4 very predictable
Increase A-P spread of implants and improved biomechanics and force distributions
Decreases cantiilevers
Avoids major bone grafting
Great success rates
Good for immediate loading and provisionalisation
