13. Treatment Angle's Classification Flashcards
What are the different full treatment appliance systems for treating Class I malocclusions
- Labio-lingual
- Johnson twin arch
- Begg
- Lingual
- Edgewise
Describe the Edgewise full arch appliance
- 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
The majority of US caucasian people have class I/II/III occlusion
I
Which is more common among US caucasian patients class II or III occlusion
II
Describe the Dewey-Anderson Classification system for Class I
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
Confused about slides 20 and 21
When do you extract first bicuspids and when don’t you
Class I Type I Non bicuspid and 1st bicuspid extractions
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
Class I type 1 2nd bicuspid extraction
Must answer yes to the following
- Crowding slight (3-6mm)
- Profile flat/slightly concave
- Molars not absolutely class I
Protrusive profiles are associated with _ crowding
moderate to severe
Flat profiles are associated with _ crowding
less
When retracting the anterior teeth what order should be followed and why
2 cuspids first and 4 incisors because less anchorage loss posterior teeth
Procedure following 4 first bicuspid extractions
- 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
Increased anchorage with fixed appliances is attained with
- Full bracket engagement provides stationary anchorage allows only bodily movement for maximum resistance
- Extra-oral reinforcement (i.e headgear)
Methods of canine retraction with fixed applianced
-Complete archwire technique (bodily movement)
Describe progression of archwires
small to larger round/rectangular
Canine retraction with complete archwire technique is done how
elastic chains or closed coiled spring
When the canines are retracted they are held back with
steel ligature wire
How are incisors retracted with the complete archwire technique
- Closing loop wire
- Elastic chains
- Headgear to reinforce anchorage
Retracting incisors leads to (elongation/retraction)
elongation
With class I type 2 what is the first treatment to be done then what is done
manage habit then retract the incisors like in class I type 1
Class I type 3 should only be corrected if
sufficient space is available
Ways to advance 1 or 2 teeth out of an anterior crossbite
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
With 3 or 4 anterior teeth in crossbite what should you be cautious of
skeletal discrepancy
Etiology of posterior crossbite if midlines don’t coincide
bilateral narrowing of the maxillary arch
Treatment for Class I type 4 (posterior cross bite)
Removable
-Expansion screw in acrylic plate
Fixed
- Quad helix
- Porter arch
- RPE
Combination
-Elastics attached to bands for single teeth upper/lower first molars
Class I type 5 should be treated how
similar to class I type 1 patients
