Interceptive Ortho II Flashcards
What are the eruption dates for permanent teeth?
6s- 6 years
1s - 7 years
2’s - 8yrs
4’s - 10yrs
3+5s - 11-12yrs
7’s - 12-13yrs
What is the early and late mixed dentition?
What problems may arise in the late mixed dentition?
- Retained deciduous teeth
- Infra-occluded deciduous teeth
- Canines (positioning)
- Overjets
When is it quite common to see retained deciduous teeth?
- no successor
- Where the permanent tooth has been pushed buccaly and is trying to erupt around the tooth
How are retained decidous teeth managed? Why is this done? (when there is a successor)
- remove teeth pretty quickly
- done because the permanent teeth have a significant capacity to drift when erupting but once fully erupted then have to be moved by appliances
What are infra-occluded teeth also known as and why?
submerging teeth as there is a step down between the permanent and the deciduous tooth
The primary tooth has become ankylosed and seem to submerge but actually everything around them is growing
How is an infra-occluded tooth diagnosed?
- visually
- percussion - will give a dull cupped sound
- radiograhs
How is an infra-occluded tooth managed? (both if it has a successor or not)
- Permanent successor?
- Observe for one year
- Studies shown that they are normally exfoliated normally
- No successor?
- Extract
- Would extract when the tooth is only 1mm of crown showing as sometimes can last for a while
Where/how do the canines develop?
They develop palatally and then migrate and lie labial and distal to the root apex of the upper laterals
When are canines palpable?
90% are palpable by 11 years
How do you assess for canines coming through and when do you do this from?
You want to palpate buccaly to try and feel the bulge of the canine
Can also check to see if the c’s are mobile
If can feel the bulge on one side/no sides or only one tooth mobile etc, this is a cause for concern and can take radiographs
From 9/10 years old onwards
What radiograhs would you take to locate an ectopic canine?
-OPT and anterior maxillary occlusal
Ectopic canines can lead to resorption of what teeth and what % are afftected?
- 15% of central incisors have some degree of resorption
- 35% of lateral incisors have some degree of resorption
Outline the management of ectopic canines.
- Extraction of c’s
- Can be done if detected early
- Would extract both to prevent midline shift
- Works up until the age of 13 with a reasonable chance of success
- After 13 years then will have to go down surgical and ortho route
The chance of success of management of canines with extraction if c’s depends on what?
- The chance of success depends on how high the canine is and how much of the adjacent incisor it overlaps
- If it doesn’t overlap the adjacent incisor by more than half (midline) then 90% success
- If more than half overlap then the chance of success drops to 60% (would still extract the c’s)
What can reverse overjets be due to?
- Dental problems
- Upper teeth tipped back and lowers tipped forward
- Could be fixed with an appliance
- Skeletal problem
- Small upper jaw and big lower jaw
- Combination of both
Note: REFER for early advice
When you refer a Class III, the orthodontist will be looking at what?
for can the patient bring the teeth edge to edge?
If they can then may be a simpler treatment with an URA.
What are the limites of angulations for the incisors for camoflauge of a Class III?
120(upper) and 80 degrees (lower)
What does it mean to camoflague?
Camouflage is when you get class I teeth accepting the skeletal underlying problem.
What are the interceptive treatment options for Class III’s?
- growth modulation
- camoflague URA
What are the options for growth modification for Class III relationships?
- Functional regulator
- maxillary protreaction
Why might there be an increased overjet?
This can be due to dental problems (top teeth tipped), skeletal problems (mandibular retrognathia) or a combination of both
What measurements for overjets will score highly on the index of treatment need?
OJ > 9mm gets a score of 5a (highest score)
OJ >6mm gets a score of 4a
Why?? - because of the risk to trauma
With an OJ, what increases risk of trauma even more? (apart from size)
Incompetent lips
What are the options for interceptive treatment for Class II’s?
Growth modification from functional appliances or headgear (headgear no longer done as not seen as acceptable)
How can functional appliances intercepively treat Class II occlusions?
- Use the forces from the muscles round the jaws to promote mandibular growth, restrict maxillary growth, tip lower teeth forward and top teeth back. All work to reduce OJ.
Note:
- 80% of patients with Class II will have mandibular retrognathia so trying to promote mandibular growth is a good thing for them
