Ortho Flashcards
class II div I skeletal & malocclusion IOTN 5A discuss skeletal class / incisor class / dental factors / reason for tx / mx & tx options
skeletal class -
class II maxilla >2-3mm in front of mandible; increased OJ, ANB >4 degrees
incisor class -
class II div 1 lower incisor edge lies posterior to cingulum plateau of upper central incisors. upper centrals are proclined or of average inclination & there is an increased OJ
dental factors of class II div 1 -
- increased OJ; incisors proclined or average
- variable OB
- can have good alignment, crowding or spacing in dentition
- habitually parted lips may lead to drying of gingivae & exacerbation of preexisting gingivitis
reason for tx -
concerns re aesthetics / re dental health / prominent incisors at risk of trauma esp with incompetent lips / OJ > 9mm x2 more likely to suffer from trauma (IOTN 5a)
mx -
a) accept; leave & monitor
1. where there is mildly increased OJ & pt not concerned
2. can give advice & use of mouth guard for trauma protection
b) attempt growth modification
1. headgear - try & restrain growth of maxilla horizontally +/- vertically
2. functional appliance i.e. twin block to utilise, eliminate or guide forces of muscle function, tooth eruption & growth to correct the malocclusion; should be used during growth & coincide with pubertal growth spurt
c) URA
1. limited role unless mild class II when overjet is due to incisor proclination & favourable OB
2. only after specialist assessment
d) orthognathic surgery
1. should be carried out when growth is complete & only when there is severe skeletal A/P discrepancy or vertical direction
2. usually involves mandibular surgery but may include maxilla
3. fixed appliances will be required before during & after
when designing a URA what does ARAB stand for
A - active component - moves teeth 0.5mm
R - retention - holds brace in 0.7mm permanent, 0.6mm deciduous
A - anchorage - resists unwanted tooth movement
B - baseplate + any modifications - provides anchorage, retention, connector.
self cure PMMA over heat cure PMMA as quicker & easier fabrication (14mins v 14hrs) but disadv is that residual monomer can be an irritant. knife edge acrylic also stops tongue playing with URA causing ulcers from trauma
prescription to reduce OJ
please construct URA to reduce OJ & continue to reduce OB
A - 22 21 11 12 Robert’s retractor 0.5mm HSSW + 0.5mm ID tubing
R - 16/26 Adam’s clasps 0.7mm HSSW + 3/3 mesial stops
A - not ideal keep an eye on it
B - self cure PMMA + FABP OJ +3mm
prescription to retract canine
please construct URA to retract canines
A - 13/23 palatal finger springs & guard 0.5mm HSSW
R - 16/26 Adam’s clasps 0.7mm HSSW & 11/21 Southend clasp 0.7mm HSSW
A -
B - self cure PMMA
prescription to retract buccally placed canines
please construct URA to retract buccally placed canines
A - 13/23 buccal canine retractor 0.5mm HSSW & 0.5mm ID tubing
R - 16/26 Adam’s clasps 0.7mm HSSW & 11/21 Southend clasp 0.7mm HSSW
A -
B - self cure PMMA
prescription for anterior xbite
please construct URA to correct anterior crossbite
A - Z spring 0.5mm HSSW (on whatever tooth in xbite)
R - 16/26 & 14/24 Adam’s clasps 0.7mm HSSW
A -
B - self cure PMMA & PBP
prescription for posterior xbite
please construct URA to correct posterior crossbite & expand upper arch
A - midline palatal screw
R - 16/26 & 14/24 Adam’s clasps 0.7mm HSSW
A - reciprocal anchorage
B - self cure PMMA & PBP
URA faults, activation, delivery checks & care instructions
component faults - Z spring encased in acrylic, UR6 Adam’s clasp arrowhead fault, UL6 Adam’s clasp flyover fault
prescription faults - southend clasp included meaning appliance won’t work, adam’s on ULC not ULD, FABP instead of PBP
to rectify? remake appliance by taking new imps
activating palatal spring - using spring former pliers 1-2mm activation
fitting a URA -
- check correct appliance for correct pt & that it matches prescription
- run finger over all surfaces to check for protruding wires & sharp acrylic
- check wirework integrity (if overworked)
- fit appliance
- check for blanching / trauma
- check posterior retention; flyovers (check first as these influence arrowheads) then arrowheads & activation
- activate to produce 1mm movement/mth
- demonstrate to pt insertion & removal & get them to do it back
- rv 4-6wkly
instructions to pt:
will feel big & bulky / likely to impinge on speech (read a book aloud to help this) / may have mild discomfort but this is a sign appliance is working / initial saliva increase 24-48hrs / wear 24hrs a day inc meal times / can remove to clean with soft brush after each meal or when taking part in contact sport & store in safe place / avoid hard & sticky foods / be cautious with hot food & drink as base plate acts an insulator / non compliance will lengthen tx / give emergency contact no
pt requiring advice on decalcification & how to avoid this as well as OHI
decalcification has the shape of the bracket, weakens the enamel to caries & leaves unsightly staining
pt selection important as high risk of decal if caries history, evidence of decal or NCTSL
OHI - tb & single tufted brush for brackets, ID brushes & superfloss, min x2 daily, modified bass technique, brushing after meals, disclosing tabs to identify missed areas
diet - limit sugar & avoid frequency, avoid snacking between meals, < 3 x daily for sugar, avoid fizzy drinks, chewing gum, sticky sweets etc, water milk crackers cheese fruit acceptable snacks, watch out for hidden sugars in foods, rinse mouth after eating
fluoride - duraphat TP 2800ppm or 5000ppm, x2 daily, warn re overdose in children. MW daily 0.05% or 225ppm, used inbetween brushing not after, fluoride varnish is prolurid 22600ppmF not duraphat as this can stain, every 4mths for prevention (not tx of decal as it will seal it in)
problems with ectopic canine / OJ / OB / peg lateral & how to determine position
risk of trauma from OJ, risk of trauma from OB (gingival stripping & abrasion on palatal surfaces of upper teeth), risk of root resorption & cyst formation
parallax to determine position - OPT & oblique occlusal radiographic views
vertical parallax = SLOB
tubehead shifted up from OPT to oblique occlusal, the canine moved together with the tubehead compared to the incisor so according to SLOB rule the canine is palatal to the incisor
retained UL A & unerupted UL1 w/ PA of dilacerated floating 21 - identify problem for pt & discuss further investigation / mx
causes of retained ULA / u/e 21 =
- trauma to A causing damage to 1; complications inc ankylosis, arrested tooth formation for 21, dilaceration, displacement
- lack of permanent successor / hypodontia
- ectopic tooth germ
- crowding
- supernumerary; tuberculate most common
signs = discolouration of A / retained A / radiographically / lateral erupts before central / >6mths since eruption of contralateral tooth
investigations = radiographic localisation via another PA or anterior occlusal, or else OPT & occlusal or CBCT for 3D view
mx =
- always palpate; UL1 is usually high & buccal
- leave & monitor; inform of risk of possible cyst / resorption
- XLA retained A leave UL1 & space maintenance ( warn still risk of cyst)
- surgical removal of both teeth & space maintenance
- refer for ortho opinion / tx & warn of risks & benefits of ortho
- auto transplantation
- XL retained A & hope for spontaneous eruption; very unlikely since dilacerated
- expose (closed or open) +/- bonding / traction but won’t work if dilacerated
20yo pt w/ class III malocclusion what are the tx options
- accept & monitor if mild
- intercept w/ URA to procline uppers; note pt is 20 so this unlikely to be an option
- growth modification with functional appliance i.e. reverse twin block or RME & protraction headgear; pt age so also unlikely to be an option
- camouflage with fixed appliances - accept underlying skeletal classification problems & move teeth with fixed ortho to hide it; procline uppers & retrocline lowers. note risks of ortho = decal, root resorption, relapse, gingival recession. usually this also inc XLA U5s & L4s (most likely lowers to reduce necessary tipping)
- orthognathic surgery w/ combined ortho; surgical manipulation of mandible +/- maxilla. requires pre surgical ortho 12-18mths for arch alignment, arch coordination, decompensation & post surgical ortho for 12mths - overall approx 36mths
