Fixed Appliances Flashcards
What are fixed appliances?
Orthodontic devices attached to teeth, cannot be removed by the patient and capable of causing tooth movement
What is bodily movement?
Tooth and crown move in the same direction
What force is required for bodily movements of teeth?
50 - 120g
What force is required for torquing movements of teeth?
50 - 100g
What force is required for rotational movements of teeth?
35 - 60g
What force is required for extrusion movements of teeth?
35 - 60g
What force is required for tipping movements of teeth?
25 - 60g
What force is required for intrusion movements of teeth?
10 - 20g
Name 5 advantages of fixed appliances over removable appliances
- All types of tooth movement possible
- Allow bodily movement
- Groups of teeth can be moved
- Detailed movement possible
- Essential for dealing with complex cases (ectopic canines, hypodontia)
Describe how bodily movement happens
- Does not move uniformly
- Tips and uprights
- Tip crown to palate, tip root to palate, tip crown to palate etc
Name 5 components of fixed appliances
- Brackets
- Bands / Bonded Buccal Tubes
- Archwires
- Ligatures (elastomeric or SS)
- Auxiliaries
Describe how the components of a fixed appliance are typically assembled on the teeth
- Brackets are bonded to incisors, canines and premolars
- Bands are cemented around molars, although, buccal tubes often used
- Wires attached with elastic modules or SS ligatures
Name 3 reasons bands or bonded buccal tubes would be used instead of brackets
- Molars
- Premolars if partially erupted or crowned
- Heavily restored tooth
Describe the features of bands
- Preformed stainless steel
- Buccal attachments welded to band
- Lingual cleat may be included
- Come in a range of sizes
Describe band selection
- Separators are worn for a week to create room for band
- Select correct band (U/L, L/R, Tooth)
- Try in and select size which is a good fit
- Should seat fully but neat fit
Describe band placement
- Select band and dry tooth
- Cement using GIC
- Check position (fully seated and parallel to cusps))
- Etch and bond with composite
Describe the archwire squence
- Progress from flexible to stiff, round to rectangular and NiTi to SS
Why may a transpalatal archwire be used?
Increase posterior anchorage and reduce amount of mesial movement of the upper molars to increase movement of canines