Interceptive Ortho II

Question 1

What are the eruption dates for permanent teeth?

Answer 1

6s- 6 years

1s - 7 years

2’s - 8yrs

4’s - 10yrs

3+5s - 11-12yrs

7’s - 12-13yrs

Question 2

What is the early and late mixed dentition?

Answer 2

Question 3

What problems may arise in the late mixed dentition?

Answer 3

• Retained deciduous teeth
• Infra-occluded deciduous teeth
• Canines (positioning)
• Overjets

Question 4

When is it quite common to see retained deciduous teeth?

Answer 4

• no successor
• Where the permanent tooth has been pushed buccaly and is trying to erupt around the tooth

Question 5

How are retained decidous teeth managed? Why is this done? (when there is a successor)

Answer 5

• 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

Question 6

What are infra-occluded teeth also known as and why?

Answer 6

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

Question 8

How is an infra-occluded tooth diagnosed?

Answer 8

• visually
• percussion - will give a dull cupped sound
• radiograhs

Question 9

How is an infra-occluded tooth managed? (both if it has a successor or not)

Answer 9

• 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

Question 10

Where/how do the canines develop?

Answer 10

They develop palatally and then migrate and lie labial and distal to the root apex of the upper laterals

Question 11

When are canines palpable?

Answer 11

90% are palpable by 11 years

Question 12

How do you assess for canines coming through and when do you do this from?

Answer 12

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

Question 13

What radiograhs would you take to locate an ectopic canine?

Answer 13

-OPT and anterior maxillary occlusal

Question 14

Ectopic canines can lead to resorption of what teeth and what % are afftected?

Answer 14

• 15% of central incisors have some degree of resorption
• 35% of lateral incisors have some degree of resorption

Question 15

Outline the management of ectopic canines.

Answer 15

• 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

Question 16

The chance of success of management of canines with extraction if c’s depends on what?

Answer 16

• 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)

Question 17

What can reverse overjets be due to?

Answer 17

• 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

Question 18

When you refer a Class III, the orthodontist will be looking at what?

Answer 18

for can the patient bring the teeth edge to edge?

If they can then may be a simpler treatment with an URA.

Question 19

What are the limites of angulations for the incisors for camoflauge of a Class III?

Answer 19

120(upper) and 80 degrees (lower)

Question 20

What does it mean to camoflague?

Answer 20

Camouflage is when you get class I teeth accepting the skeletal underlying problem.

Question 21

What are the interceptive treatment options for Class III’s?

Answer 21

• growth modulation
• camoflague URA

Question 22

What are the options for growth modification for Class III relationships?

Answer 22

• Functional regulator
• maxillary protreaction

Question 23

Why might there be an increased overjet?

Answer 23

This can be due to dental problems (top teeth tipped), skeletal problems (mandibular retrognathia) or a combination of both

Question 24

What measurements for overjets will score highly on the index of treatment need?

Answer 24

OJ > 9mm gets a score of 5a (highest score)

OJ >6mm gets a score of 4a

Why?? - because of the risk to trauma

Question 25

With an OJ, what increases risk of trauma even more? (apart from size)

Answer 25

Incompetent lips

Question 26

What are the options for interceptive treatment for Class II’s?

Answer 26

Growth modification from functional appliances or headgear (headgear no longer done as not seen as acceptable)

Question 27

How can functional appliances intercepively treat Class II occlusions?

Answer 27

• 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