Week 4

Question 1

3 possible approaches to skeletal malocclusions

Answer 1

Growth Modification
Camouflage
Surgical Treatment

Question 2

5 sites of facial growth

What happens when each is messed up

Answer 2

Sutures - small cranial vault
Nasal septum - AP growth
Synchondrosis - Maxillary deficient 
Condyle - grows off to one side
Alveolus - deficient ridge

Question 3

Which growth sites are most modifiable?

Answer 3

Sutures

Alveolus

Question 4

What two things do you need to modify growth?

Answer 4

A growing patient
Ability to affect structures

Eg: alveoli need teeth or a functioning unit in order to adapt it

Question 5

What are the ideal ages to start growth modification treatment in males and females?

Answer 5

At the start of the growth spurt.

Females: 10-12
Males: 12-14

Question 6

What are the best ways to determine age/growth?

Answer 6

Height and weight measurements
Secondary sex characteristics
Menarche - indicates end of peak growth
Serial cephalometric radiographs
Cervical vertebrae

Question 7

What percentage of people have class II and class III malocclusions?

Answer 7

Class 2: 20%

Class 3: less than 3%

Question 8

When is growth modification indicated?

Answer 8

Minor to moderate skeletal problems

Won’t work for severe skeletal

Question 9

Discuss the ease/difficulty of modifying growth in…

Maxillary vs mandible
Vertical vs Transverse

Answer 9

Maxilla easier than mandible (suture vs condyle)

Transverse easier than vertical. Transverse is the first to stop growing, which is why we start early. Vertical doesn’t stop for a long time so it’s hard to stop.

Question 10

Tx of class 2 with max protrusion

Answer 10

Headgear

Question 11

Tx of class 2 with mandibular retrusion

Answer 11

Functional appliances and headgears

Question 12

Tx of Class 3 Maxillary retrusion

Answer 12

Reverse pull Face mask

Functional appliances

Question 13

To of Class 3 mandibular protrusion

Answer 13

Functional Appliance

Chin cup- not found to be effective

Question 14

Can skeletal changes be maintained?

Answer 14

Skeletal changes tend to go back during the maintenance period

Question 15

Is early class II treatment beneficial

Answer 15

No. Early mixed dentition is of no benefit to ultimate growth over late mixed dentition

Question 16

Is early class III Treatment beneficial?

Answer 16

Protracting a retruded maxilla is shown to be effective before the age of 10.

Restricting the mandible may have some short term benefit, but no long term.

Question 17

Is early treatment if of posterior crossbite effective?

Answer 17

Yes.

Question 18

What are three surgical solutions to A-P discrepancy.

Answer 18

Le Fort I - for maxilla
BSSO - for mandible
Genioplasy - decrease of the chin

Question 19

Surgical solution to transverse problem

Answer 19

SA RPE
2 - piece LeFort
Mandibular midline osteotomy
Distraction osteogenesis

Question 20

Why is pre-surgery orthodontics often indicated?

Answer 20

For the elimination of dental compensation
Dental alignment
Any other procedure to facilitate optimal surgery

Question 21

Which surgical procedures are most and least stable?

Answer 21

Most stable:
Moving the maxilla up, mandible forward

Least stable:
Moving mandible back, maxilla down or wider

Question 22

What type of patient is camouflage treatment indicated for?

Answer 22

Non-growing
Acceptable facial esthetics
Minor-moderate skeletal prob
Adjust dental relationships

Question 23

When can you no longer use an RPE without surgery?

Answer 23

15 for females, 16 for males

Question 24

Advantages of DO

Answer 24

No bone graft
More bone movement
Good for infants and young children
Less invasive

Question 25

Disadvantage of DO

Answer 25

Technique and equipment sensitive
Less precise control 
Px compliance required
Increased chance of infection
Long tx

Question 26

Indications for DO

Answer 26

Severe micrognatia in infants and children (Pierre Robine Sequence)
Severe constricted mandible or maxilla

Question 27

Contraindications of DO

Answer 27

Lack of adaquate supporting bone
No patient compliance
Can be corrected with another othognathic surgery without bone graft