Ortho Lab Flashcards
what are advantages of a fixed appliance
can carry out 3d movement of the tooth
can correct rotations
can utilise bodily movement and torque
compliance is not an issue as it cannot be removed by the patient
less intrusive on tongue space
minimal palatal coverage
can move multiple teeth
what are disadvantages of a fixed appliance
oral hygiene must be good and it is made more difficult
risk of decal
risk of root resorption
no intrinsic anchorage
can cause soft tissue trauma
poor aesthetics
cost
when would a fixed appliance be used
to correct mild to moderate skeletal discrepancies - camouflage
to correct rotations, spaces, intrusion and extrusion
what are the components of a fixed appliance
archwire
bracket
ligature
bands
hooks and elastics
force generating components - spring coils
what is the function of the archwire
the wire contains the prescription, it has shape memory. when put through the brackets, the shape is distorted, so carries out a force on the teeth whilst trying to obtain its original shape
what is the function of the bracket
the interface between the tooth and the archwire, transmits force from wire to tooth. bonded to tooth with etch, bond and composite
what is the function of the ligature
to hold the archwire in place on the bracket, can be elastic or twisted module
give some examples of how anchorage can be achieved with fixed appliance
temporary anchorage device - non-osseointegrating mini screws in palate
transpalatal arch
transpalatal arch with nance button
baseplate
what are the advantages of URA
tipping of teeth, good for correction of overbite, removable so good for OH, cheaper than fixed, shorter chairside time, less specialist training, good anchorage
what are the disadvantages of URA
removable - poor compliance
can only move one or two teeth
not good for rotations
less precise tooth movement
requires technical staff
what are the uses of ura
tipping of teeth, reduce OB, habit breaker, retainer, expand arch
what are the uses of study casts
diagnosis
treatment planning
monitoring treatment
designing appliance
discussing and explaining to patient
teaching
what are the components of stainless steel
72% iron
18% chromium
1.7% nickel
0.3% carbon
what are displacement forces
mastication, speech, tongue, gravity, active component
what components make up a URA
active component, retention, baseplate
what are the benefits of baseplate and what modifications can be done
anchorage, connector and retention
can also be modified - FABP to reduce OB - OJ +3MM
Posterior bite plane - to increase space for correcting crossbites
name 5 active components, their measurements and uses
palatal finger spring with guard - 0.5mm HSSW - retract teeth in line with arch (3s mainly)
z-spring - 0.5mm HSSW, correct crossbite, some rotational movement
buccal canine retractor - 0.5mm HSSW with 0.5mm ID tubing - retract buccally placed canines
roberts retractor - 0.5mm HSSW with 0.5mm ID tubing - reduce overjet
midline palatal screw - expand upper arch
name 3 retention components and their measurements
adams clasp - 0.7mm if adult tooth, 0.6mm for deciduous HSSW
southend clasp - 0.7mm HSSW
labial bow - 0.7mm HSSW
mesial stop - 0.7mm flattened HSSW
how should a URA be delivered
check right appliance for right patient
right design that you asked for
inspect appliance for sharp edges or areas for potential trauma
inspect wire work for work hardening
insert appliance and check for areas of blanching or trauma
check posterior retention - flyover and arrowhead
check anterior retention
activate appliance
demonstrate to patient how to insert and remove appliance - get the patient to demonstrate this back to you
book review appt 4-6 weeks
what advice should be given to patients when delivering URA
should be worn 24/7 including eating and sleeping
should be removed after eating and cleaned with soft brush
should be removed during contact sports and stored in hard container
will feel big and bulky but will adjust to it
will have some discomfort but this means it working
should avoid hard sticky foods that could damage the appliance and be careful with hot liquids
speech will be altered - practice reading aloud
excess salivation will happen, will reduce after 24 hours
poor compliance will increase tx time
provide emergency contact number incase of any incidents
what are some signs of good wear of URA
patient comes in wearing it
ask the patient
patient can handle the appliance - insertion and removal
patient can speak with it in
no excess salivation
the tooth has moved
the active component is no longer active
there is wear on the appliance
what would be the ARAB for retracting canines in line with arch and reduce OB
a - palatal finger spring with guard 0.5mm HSSW
r - adams clasp 0.7mm, southend clasp 0.7mm
a - fine
b - self cure PMMA, FABP OJ + 3mm
what would be the arab for retracting buccally placed canines and reduce
a - buccal canine retractor 0.5mm HSSW with 0.5mm ID tubing
r - adams clasp 0.7mm, southend clasp 0.7mm
a - fine
b - self cure PMMA, FABP OJ +3mm
what would the arab be for reducing OJ and OB
a - roberts retractor 0.5mm HSSW + 0.5mm ID tubing
r - adams clasp 0.7mm HSSW
a - short roots + baseplate
b - self cure PMMA FABP OJ + 3mm
what would the arab be to correct anterior crossbite 12
a - z-spring 0.5mm HSSW
r - adams clasp 0.7mm 6s and 4s
a - moving one tooth
b - self cure PMMA + posterior bite plane
what would the arab be to correct posterior crossbite
a - midline palatal screw
r - adams clasp 0.7mm 6s and 4s
a - reciprocal anchorage
b - self cure PMMA + posterior bite plane
what is the use of a quadhelix
bilateral expansion, fan type expansion, asymmetrical expansion, cleft palate expansion, assist habit breaker, modified to procline incisors, rotation of molars
