MF APPLIANCES

Question 1

What is the effect of Class II correctors?

Answer 1

• Headgear effect
• Pressure on mandibular anterior
• Dentoalveolar changes
• Mandibular corpus growth

Question 2

What is the effect of Forsus?

Answer 2

Procline lower incisors
(NOT increase SNB)

Question 3

What is the effect of MARA?

Answer 3

• Less incisor proclination than Herbst
• Less of a headgear effect as Herbst, so does distalize U6s some

Question 4

What is the effect of Herbst?

Answer 4

• Open bite
• Push lower incisors forward and molars distal

Question 5

What is the effect of the Twin Block?

Answer 5

• Both skeletal and dental
• Cap lower incisors
• Can increase facial height by adjusting acrylic over molar teeth (NOT long term increase in mand length)
• LATE MIXED dentition
• Does increase SNB, but not long term correction

Question 6

What is the effect of a Distal Jet?

Answer 6

• Better in pushing molar back BUT collapses into crossbite, and lots of upper incisor proclination
• May need to use headgear (pendulum better)

Question 7

Can you treat a patient in late mixed dentition with a functional appliance?

Answer 7

Yes

Question 8

What does the Carriere Distalizer do?

Answer 8

• Proclines lower anterior teeth
• Distally rotates upper molar
• Extrudes lower canine?

Question 9

What does Cervical Pull Headgear do?

Answer 9

• Molar extrude and tips distal
• For roots to move distal, need shortened outer bow to be higher than center of rotation of rotation (more gingival)

Question 10

What does High Pull Headgear do?

Answer 10

• Above center of rotation: molar intrude and distal root tip

Question 11

How does Asymmetric Headgear work?

Answer 11

Longer bow on the class II side (further away from the cheek)

Question 12

What does the LLHA do?

Answer 12

• Maintains leeway but may impact L7s
• Helps with vertical anchorage
• Prevents molars from mesializing and lower incisors from distalizing

Question 13

What does an Intrusion Arch do?

Answer 13

Counters the side effects with High Pull Head Gear with short outer bow and TPA

Question 14

What does a TPA do?

Answer 14

• Maintains width after expansion
• De-rotating medial rotated first molars
• Maintain leeway space
• NOT A-P anchorage

Question 15

What does a Lip Bumper do?

Answer 15

• Lateral expansion
• Procline incisors
• Tip back molars
• Alleviate crowding
  (Effective no longer than 300 days; see 50% in 100 days)

Question 16

What quality of bone, amount of force, and qualities are important for TADs?

Answer 16

• Quality of bone: cortical
• Amount of force 100-200g immediately and force vector
• Most important: increased diameter (NOT LENGTH)
• Cortical thickness (vs bone mineral density - cortical bone is cortical bone - need more of it)

Question 17

SARPE/RPE Limitations

Answer 17

• Coronoid process
• 10mm expansion (avg 12mm)

Question 18

What is the effect of Class II elastics?

Answer 18

Achieve correction by mostly dentoalveolar changes; therefore, the long term effects are the same as with a functional appliance
(Clockwise rotation, more relapse (TT)??)

Question 19

What is the effect of Class II elastics through the center of resistance on maxilla and distal on the mandible?

Answer 19

No change in maxilla, steepen mandibular plane

Question 20

What is the effect of sleep apnea appliances?

Answer 20

• Change in occlusion
• NOT increased TMD (Per Houston, but Dallas says yes) or salivation

Question 21

When and how is protraction face mask for Class III patient used?

Answer 21

• Early mixed
• Should be 30 degrees below occlusal plan AND 350-450g (1 lb) (Orthopedic force)
• Not used in 10-14 year old group (need early skeletal changes seen in 8 years old and then declines 10-11)
• Side effect: Procline lower incisors and retrocline upper incisors (don’t need expansion with protraction)
• 75% successful - don’t use high angle cases