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
Name 2 commonly used classic fixed appliance systems
- Begg appliance
2. Edgewise appliance
Evaluate the Begg appliance
+ 3 stages
+ Relies on extns
+ Good speed of movement
- Lack of precision
Evaluate the Edgewise appliance
\+ Mechanically simple \+ Precise \+ Versatile - Slower speed of movement - Demanding on anchorage
What is a common bracket dimension used?
- 022 x 0.028 bracket slot
- 022 inch in occluso-gingival dimension
- 028 inch in labio-lingual dimension
Name 2 current fixed appliance systems used derived from Begg appliance and Edgewise appliance
- Tip-Edge appliance derived from Begg appliance
2. Straight-Wire appliance (SWA) derived from Edgewise appliance
Name 4 advantages of Tip-edge appliance
- Permits tooth tipping in early staging
- Anchorage saving
- Versatile
- More precise than Begg
Name 4 disadvantages of Tip-edge appliance
- Narrow bracket with poor control
- Intermaxillary elastics required
- Complex in stage 3
- Based on extn philosophy
Describe how brackets are correctly placed for straight-wire appliances
Dots are colour coded on disto-lingual lug to ensure correct placement
Name 6 stages of treatment in SWA
- Anchorage management
- Levelling / Alignment
- Overbite correction
- Overjet correction
- Space closure
- Finishing and detailing
Name 5 advantages of straight-wire appliance
- Reduce wire bending
- Use of sliding mechanics
- Precision and finishing
- Flexibility and biomechanics
- Multiple bracket design
Name 4 disadvantages of straight-wire appliance
- Friction
- Perceived anchorage demands
- Adjustments still required for individual patients
- Deceptively simple
What are 1st order bends on straight-wire appliance prescriptions?
In-out of the plane of the upper arch
What are 2nd order bends on straight-wire appliance prescriptions?
Up-down in inverted plane of the arch used to tip canines
What are 3rd order bends on straight-wire appliance prescriptions?
Incisor torquing bends
Describe straightwire brackets
- Stainless steel brackets
- May be ceramic (tooth coloured) especially if private patient
- Rectangular horizontal slot
- 0.018 or 0.022 inch slot size
Describe how to deal with the orthodontic emergency:
Long Wire Catching Cheek
- Safety distal end cutters can be used
- Most GDPs do not have this tool so straight diamond bur with suction used
Describe how to deal with the orthodontic emergency:
Loose Bracket
- Rotate bracket around so the base is against the tooth
- Untie the module with probe
- Slide bracket mesially and distally ad remove
- Contact orthodontist ASAP (patient or referral letter)
Describe how to deal with the orthodontic emergency:
Missing Bracket
- Enquire with patient risks of inhaling or ingested
- If possibility of inhalation or ingestion, seek advice from A+E
Describe how to deal with the orthodontic emergency:
Loose Orthodontic Band
- Gently reseat the band and trim excess wire
- Use amalgam packer or burnisher to press into place and burnish
- Ask patient to attend orthodontist and explain what has occurred
Describe how to deal with the orthodontic emergency:
End Steel Ligature Catching Lip
- Take wire director and turn under the lug of the bracket to ensure does not catch on lip anymore
- Refer to orthodontist
Describe how to deal with the orthodontic emergency:
Acute Gingival Inflammation Close to Band
- Intensive OHI including disclosing tablet, chlorhexidine, localised scale and polish
- Contact orthodontist for possible removal of appliance
Describe how to deal with the orthodontic emergency:
Tooth Feeling Loose
- Premature contacts can cause tooth to become particularly mobile
- Check for traumatic occlusion
- Check vitality, colour, TTP or periodontal involvement
- Reassure / Attend orthodontist
Describe how to deal with the orthodontic emergency:
Painful Teeth
- Check no damage to appliance or traumatic occlusion
- Reassurance it is normal for 3-4 days following bonded bridge adjustment
- Analgesia advice
- Contact orthodontist if necessary
Describe how to deal with the orthodontic emergency:
Broken Archwire
- Take lesser part of the wire and with straight probe, untie modules and remove
- Trim the remainder of wire and make comfortable
- Refer to orthodontist
Describe how to deal with the orthodontic emergency:
Broken URA
- If clasp fractured, remove from appliance
- If acrylic fractured, smooth rough edge
- Advise the patient to attend the orthodontist
Describe how to deal with the orthodontic emergency:
Loose URA
- Adjust clasps with Adams former
- Advise patient not to click appliance in and out
- If clasps are broken or missing, advise patient to return to orthodontist
Describe how to deal with the orthodontic emergency:
Inflamed Palate with URA
- More than likely candidal infection
- OHI and diet advice
- Prescribe miconazole oromucosal gel
- Advise patient on how to properly clean URA
