#4 Skeletal Changes

Question 1

What are the 3 major clinical problems of maxillary growth?

Answer 1

• Maxillary hypoplasia (Class III)
• Maxillary Prognathism (Class II)
• Transverse deficiency (posterior cross bite)

Question 2

How many hours a day does maxillary growth retaining head gear need to be worn?

Answer 2

12-16 hours a day *not 6 hours like teeth

Question 3

How much skeletal moment can Maxillary protraction-face mask and reverse pull head gear induce?

Answer 3

3mm or less

• Usually done before age 10-11
• Often lasts 6-8 months

Question 4

What is a palatal expander is used to treat what?

Answer 4

Often used to treat transverse deficiency .

*Palatal suture is the target here.

Question 5

How fast is Rapid palatal expansion?

Answer 5

1mm/day (mostly adolescent patients) used 2-3 weeks

Question 6

How fast is Slow palatal expansion?

Answer 6

1mm/week (used for late adolescent or young adult)

Question 7

How long must retention be maintained after palatal expansion?

Answer 7

3-6 months for bone consolidation

Question 8

W-arch and Quad helix appliances instead of Jackscrew-type expanders are often used for who?

Answer 8

Preschoolers/Preadolescent (rare)

Question 9

RPE in adolescents and preadolescents produces what _____% dental and ______% skeletal movement.

Answer 9

50%-50%

Question 10

For large skeletal moment in palatal expansion ________ is required.

Answer 10

(SARPE) surgical assisted RPE

Question 11

T or F, Functional appliances can accelerate mandibular growth, but may not increase the final size of the mandible.

Answer 11

True

Question 12

What are common unwanted effects of functional appliances?

Answer 12

Lower incisor proclination and upper incisor retroclination (which might help with over-jet in some patients, but might not be good choice for patients who already have too much proclination or retroclination)

Question 13

What is the most common treatment for mandibular prognathism?

Answer 13

Mandibular surgical setback after the cessation of growth.

*Mandibular restraining chin cup is rarely used.

Question 14

T or F, orthodontics is great way to widen the mandible….

Answer 14

Nope, the mandible fuses at 7-8 yrs old and so surgical procedure (distraction osteogenesis) is the best option usually

Question 15

What orthodontic device can “kind of” achieve mandibular widening?

Answer 15

Schultz and Williams appliances, but they actually expand the dento-alveolus, but not the basal bone.

Question 16

What is distraction osteogenesis?

Answer 16

Basically, create and maintain a gap in bone structure to induce bone growth.

Question 17

What are the 4 main passes of Distraction osteogenesis?

Answer 17

1. Latency = time between operation and start of distraction.
2. Distraction = the period that distractor activation takes place.
3. Consolidation = the post distraction period (APPLIANCE STILL IN PLACE) to allow new bone to form.
4. Remodeling = the period that the regenerated bone continues to remodel (after appliance removal)