ortho 4 zoom notes Flashcards
what is used to bring buccally placed canines back into position
- buccal canine retractor
why d you use a buccal canine retractor instead of a palatal finger spring for buccally placed canine
- finger palatal spring would only pull back and not into line
why is there tubing on a buccal canine retractor
- make it more rigid as otherwise it can be easily distorted
why do you only move the canines initially and not also fix the overjet as well
- moving anymore than just the canines would affect the anchorage
when are flat anterior bite planes used
- only ever used on the correction of overbites
why must you add the extra 3mm onto the FABP
- don’t want lower teeth getting trapped behind the bite plane
- adding on 3 stops them getting trapped
- prevents lower incisors becoming retroinclined
what is the dimensions of the FABP
- size of OJ + 3mm
why do lowers come up to meet uppers rather than uppers moving down
- uppers can’t move down as they are held in place by the appliance
what does the FABP do
- opens up space between the posterior teeth to allow the lowers to move up to meet uppers
how do Adam’s claps work
- applies the principles of either using or blocking undercuts
- part engages the undercut and this is how we get retention
- comes interdentally between the 5 and 6, and the 6 and 7
what does the bridge of the Adam’s clasp do
- keeps the buccal aspect away
- keeps cheek away
- gives patient area to go in and remove appliance
which part of Adam’s claps engage undercut
- arrowhead
which part of the Adam’s claps goes interdentally
- flyover
what is the leg of the Adam’s clasp
- goes down into palatal region
- needs to be gap between the leg and the palate to allow for the acrylic
- needs to be a gap of about 1mm between wire work and palate to allow for space for baseplate
what is the tag of the Adam’s clas
- gives some mechanical retention to stop component sliding out of acrylic
- because SS is so smooth, need to put this on to lock/grip it in place to stop it getting pulled out acrylic
which part of the Adam’s clasp needs adjusted first
- adjust flyover first before the arrowhead
- if did arrowhead first, then it would move again anyway when you try to adjust the flyover
what happens if the flyover is in the wrong position
- prop occlusion open
- metal fatigue = from biting on it until it reaches a point where it can fracture
- gum stripper = makes arrowhead irritate the gingiva
- can change shape of wire = can become non-functional
why do we fix the flyover before the arrowhead
- if fix arrowhead first, can then move again once fix flyover
what is the aim of the palatal finger spring
- move a tooth straight back
what does the coil of a palatal finger spring do
- where the force is exerted from
how does the coil of a palatal finger spring work
- works by uncoiling = this is how it moves the tooth
- wind wires up in coil
- want it to uncoil over a period of time which moves the tooth
what does the active arm of the palatal finger sprig do
- way in which the force is applied
- comes halfway around the canine
- only point where it applies the force is the corner of the canine tooth
why is the active arm of the palatal finger spring wrapped round the canine
- if only goes to the corner (where force is exerted), tooth could start to rotate because force coming from an angle
- so, we hug tooth with active arm to keep it going in correct orientation
what does the guard wire of the palatal finger spring do
- palatal spring will slide along the guard without interfering the palate
- allows active arm to move without traumatising soft tissue or being impinged by it
how do we activate the finger palatal spring
- once a month need to activate it again to make it work again
- adjust the coil
- make sure active arm is tight around canine = as it moves away from tooth over the course of the month
why does the active arm come away from the canine during the month
- as tooth moves back the distance from the coil to the corner of the tooth is a lot further than whenever the tooth has moved back
- as the wire uncoils it gets longer = it uncoils when it is activated so gets longer
what are the stages of fitting a URA
- ensure patient details match details supplied for appliance
- check appliance matches design specifications
- inspect appliance and run your finger over it to check for any rough edges
- check integrity of wirework (no work hardening)
- insert appliance in patients mouth and check for areas of trauma
- check posterior retention = first flyovers of Adam’s clasp then arrowhead
- check anterior retention
- activate the appliance
- demonstrate to patient correct procedure for insertion and removal
- book review appointment
how much tooth movement should here be a month
- about 1mm
what is a Roberts retractor
- looks like a buccal canine retractor but is joined in the middle
- tubing comes distal to canines with coil for activation
- used for overjet
how do we stop the canines from relapsing when trying to move the anterior teeth back
- use stops
- don’t fall under ARAB
- flattened so little thinner
- lie passively to mesial aspect of canines
- don’t apply force, just simply passive to prevent canines going forward
how is the anchorage when moving anterior teeth to fix OJ
- not ideal as we are moving 4 teeth but is ok
- we get away with it because they are the shortest rooted teeth in the upper
- not brilliant but keep and eye on it
what is the problem if we use Roberts retractor
- can’t put south end clasp on for retention anteriorly
what is ideal about the Roberts retractor
- because the wire work is halfway up into undercut area of Robert’s retractor can offer some retention
- but it is an active component and just by luck it offers some retention too
what is the problem with FABP
- it is in the way of the upper anterior teeth tilting back
- impossible for upper teeth to move back when there is acrylic jammed behind it
how can you counteract problem of FABP preventing anterior teeth moving back
0- need to trim a bit off the FABP at chair side each month
- need to trim it at an angle = chamfer it
- allows for movement for the tooth to come back
why can’t we use a posterior bite plane instead of FABP to fix a OJ
- it would prop open the bite
- works to bring them back until it is removed then will relapse
what do you need to inform patient about when giving them URA
- appliance will feel big and bulky
- may cause excessive salivation
- may impinge speech for a short period of time
- may cause initial discomfort
- need to be warn 24/7
- remove after every meal and clean
- don’t wear during contact or active sports
- avoid hard/sticky foods and cautious with hot food or drinks
- missing appointments and non-compliance will significantly lengthen treatment time
- provide emergency contact details
if having to use Adam’s clasp on deciduous teeth what gauge of wire is used
- 0.6mm instead of 0.7mm
what is good about z-springs
- they can allow a little bit of rotational movement, instead of just tipping and tilting
how does Z-springs work
- if want to move tooth straight forward activate both coils
- if want to include some rotational movement activate only one coil = movement in opposite direction of coil activated
