13. Treatment Angle's Classification

Question 1

What are the different full treatment appliance systems for treating Class I malocclusions

Answer 1

• Labio-lingual
• Johnson twin arch
• Begg
• Lingual
• Edgewise

Question 2

Describe the Edgewise full arch appliance

Answer 2

• 3D control
• Requires archwire bends
• Bodily movement of teeth
• Lingual endgewise is when brackets are on the lingual surfaces of the teeth
• Ceramic edgewise is when the brackets are made of ceramic

Question 3

The majority of US caucasian people have class I/II/III occlusion

Answer 3

I

Question 4

Which is more common among US caucasian patients class II or III occlusion

Answer 4

II

Question 5

Describe the Dewey-Anderson Classification system for Class I

Answer 5

Class I type 0
-No abnormalities

Class I type 1

• Crowded, rotated upper/lower anteriors
• Crowded lower normal upper anteriors

Class I type 2

• Protruded, spaced upper anteriors
• Protruding spaced upper anteriors and open bite

Class I type 3

• Anterior crossbite- 1 or 2 upper incisors
• Anterior crossbite- 3 or 4 upper incisors (caution skeletal discrepancy)

Class I type 4
-Posterior crossbite

Class I type 5
-Posterior space loss/mesial drifting 6 year molars via caries, early extraction

Question 6

Confused about slides 20 and 21

Answer 6

When do you extract first bicuspids and when don’t you

Question 7

Class I Type I Non bicuspid and 1st bicuspid extractions

Answer 7

Must answer yes to the following

• Crowding between 6-8 mm in each arch
• Class I molars canines
• Mandibular occlusal plane angle between 14-20 degrees
• Tip of lower incisor 2 mm ahead of A-Po plane
• Profile convex

Question 8

Class I type 1 2nd bicuspid extraction

Answer 8

Must answer yes to the following

• Crowding slight (3-6mm)
• Profile flat/slightly concave
• Molars not absolutely class I

Question 9

Protrusive profiles are associated with _ crowding

Answer 9

moderate to severe

Question 10

Flat profiles are associated with _ crowding

Answer 10

less

Question 11

When retracting the anterior teeth what order should be followed and why

Answer 11

2 cuspids first and 4 incisors because less anchorage loss posterior teeth

Question 12

Procedure following 4 first bicuspid extractions

Answer 12

• Retract canines (relieves incisor crowding) Done with removable ONLY IF crowns mesial to the root apicies otherwise crowns will tip
• Retract incisors (With removable only id upper incisor angulation >25 or crowns will tip)
• Retention

Question 13

Increased anchorage with fixed appliances is attained with

Answer 13

• Full bracket engagement provides stationary anchorage allows only bodily movement for maximum resistance
• Extra-oral reinforcement (i.e headgear)

Question 14

Methods of canine retraction with fixed applianced

Answer 14

-Complete archwire technique (bodily movement)

Question 15

Describe progression of archwires

Answer 15

small to larger round/rectangular

Question 16

Canine retraction with complete archwire technique is done how

Answer 16

elastic chains or closed coiled spring

Question 17

When the canines are retracted they are held back with

Answer 17

steel ligature wire

Question 18

How are incisors retracted with the complete archwire technique

Answer 18

• Closing loop wire
• Elastic chains
• Headgear to reinforce anchorage

Question 19

Retracting incisors leads to (elongation/retraction)

Answer 19

elongation

Question 20

With class I type 2 what is the first treatment to be done then what is done

Answer 20

manage habit then retract the incisors like in class I type 1

Question 21

Class I type 3 should only be corrected if

Answer 21

sufficient space is available

Question 22

Ways to advance 1 or 2 teeth out of an anterior crossbite

Answer 22

Removable

• Hawley with Z-springs
• Open excessive overbite with biteplate

Fixed

• Cemented inclined plane (hx of fractured teeth on blow to mouth DONT USE)
• Brackets with light archwire (+ vertical loops)

**Look at pictures on slide 39

Question 23

With 3 or 4 anterior teeth in crossbite what should you be cautious of

Answer 23

skeletal discrepancy

Question 24

Etiology of posterior crossbite if midlines don’t coincide

Answer 24

bilateral narrowing of the maxillary arch

Question 25

Treatment for Class I type 4 (posterior cross bite)

Answer 25

Removable
-Expansion screw in acrylic plate

Fixed

• Quad helix
• Porter arch
• RPE

Combination
-Elastics attached to bands for single teeth upper/lower first molars

Question 26

Class I type 5 should be treated how

Answer 26

similar to class I type 1 patients