Interceptive Orthodontics Flashcards
Interceptive orthodontics
- ‘any procedure that will reduce or eliminate the severity of a developing malocclusion’
general practitioners need to be able to spot
- refer when needed
3 characteristics of deciduous dentition
incisors more upright
spaced
wear - thin layer of enamel
eruptioins of deciduous dentition
6 months - 2.5 years
a-b-d-c-e
lowers before uppers
no spacing in deciduous dentition ->
66% will develop crowding
<3mm spacing in deciduous dentition ->
50% crowding
3-6mm spacing in deciduous dentition ->
20% crowding
>6mm in deciduous dentition ->
no crowding
what is likely if there is missing or double teeth in deciduous dentiton
- fusion of central and lateral incisor
- likely Absent permanent successor
eruption dates permanent dentitions
6s
6 years
1s
7years
2s
8years
4s
10years
3s and 5s
11-12years
7s
12-13years
variation exists
6s erupt
6 years
1s eruot
7 years
2s erupt
8 years
4s eruot
10 years
3s and 5s erupt
11-12 years
7s erupt
12-13 years
early mixed dentition
6-8 years
6s, 1s, 2s erupted
late mixed dentition
10-13 years
4s, 3s and 5s, 7s
lower labial crowding that can improve spontaneously
up to 3.5mm of crowding may spontaneously improve
- Primary canines present with permanent incisors
Grow transversely naturally and improve (3.5mm till 10)
antropoid spacing
space that is localized mesial to the upper primary canine and distal to the lower primary canine
ugly duckling stage effect on upper incisors
spaced upper incisors
- diastema
- laterals pointing distally
- upper canines leaning against upper distal aspect of lateral roots as the 3s erupt the spacing will disappear
Despite mixed dentition looking spaced it is common to have crowding (need to fit in 3, 4, 5 between 2 and 6)
size of diastema that will close naturally
<2.5mm should close between mixed and permanent dentition transition
frenectomy has little effect on longterm closure of diastema - not advocated
% diastemas at 6 yeards Vs 12 Years
6years 96% have diastema
12years 7% have diastema (3’s erupted – more space than c)
what is not advocated for diastema management
frenectomy - little effect on long term closure
4 things needed to know about development of mixed dentition
- knowledge of normal
- sequence
- symmetry
- chronological guidelines
issue here
Issue in sequence of eruption
- Deciduous upper centrals (attrition and erosion worn)
- But have both permanent laterals
Shouldn’t – CENTRALS BEFORE LATERALS
- History, examination and radiographs – something wrong
issue here
symmetry
- Contralateral tooth should erupt within 6 months
Upper right central fully erupted – not left one
- But left lateral has -> alarm
3 causes for unerupted central incisors
- supernumeraries
- trauma/dilaceration
- other pathology
management of supernumeraries
- Remove deciduous and supernumeraries
- Create space
- Expose/bond
- Monitor (>1.5years)
- Most will erupt between 1.5-2 years
Bond onto unerupted tooth possible (chain to pull down) or should just make space for it - debate
- 80% 16 months Av. If you only make the space
what is not allowing 21 to erupt?
Present but supernumerary tooth bocking eruption
history and exam for trauma causing issue in eruption sequence
dilaceration
History – ask about trauma
- Usually remembered as significant
Exam
- Palpate to see where incisor has gone
- Radiograph – see it is displaced
- Trauma to deciduous tooth transmits force up to hertwigs root sheath
- Bend
- Significant – no way can line up as part will be exposed if crown straight (non vital)
- Need removed
- Bend
- Trauma to deciduous tooth transmits force up to hertwigs root sheath
issue here
- Symmetry and sequence issues*
- 11 but no 21, 22 has started to erupt*
3 aetiology possibilities of median diastema
- Normal (small teeth)?
- Supernumerary? 10%
- Missing teeth?
radiograph
7 cases for interceptive orthodontics
- impacted 6s
- potential crowding
- early loss of deciduoud teeth
- carious 6s
- cross-bites
- transposed teeth
- habits
leeway space
normal development
difference between e,d,c and 3,4,5
- Mandibular 2.5mm
- Maxillary 1.5mm
deciduous teeth wider than permanent teeth
Measure from mesial 6 to distal 2 – want to have 18.5mm for no crowding
mm spacing for no crowding
18.5mm
measure from mesial 6 to distal 2
balancing
take contralateral on other side of same arch
compensating
take out opposing tooth
early loss of deciduous teeth effects
localises crowding
effect varies with
- crowding
- age
- arch
crowding effect on early loss of deciduous teeth
more crowding = greater balance
age impact of early loss of deciduous teeth
loss early = larger than if naturally about to lose
management techniques of early loss of deciduous teeth
- Balancing – take contralateral on other side of same arch
- Compensating – take out opposing tooth
management early loss As and Bs
little impact
don’t balance or compensate
management early loss of Cs
balance
- midline will shift - unless very spaced
- as permanent incisors are present
management of early loss of Ds
small CL shift - balance if already under GA potentially
management of early loss of Es
- Not to balance – no effect on centre line
- Major space loss
- significant mesial drift of 6 – compound a future crowding issue (less space for 3, 4, 5)
- Upper > lower rate of mesial drift
which arch has a faster rate of mesial drift
upper > lower
significant mesial drift of 6s if Es lost early - compound a future crowding issue (less space for 3, 4, 5)
when to assess carious 6s
assessment at 9 years
- any doubts re long term prognosis - refer for advice
6s extraction general rules in relation to both arches (class 1) 3
- If extracting lower take upper
- Don’t balance with sound tooth – tx each side mouth separately
- If extracting upper don’t necessarily take lower
why if extracting lower 6 take out upper 6?
upper 6s will overerupt and impinge gingiva (nothing to occlude against)
but if extracting upper 6 don’t necessarily take out lower 6
5 ideal condition for extraction of 6s
- 7s furcation forming
- 8s present
- Class 1 av/reduced OB no skeletal element
- Moderate lower crowding
- Mild/moderate upper crowding mesial drift faster
assess this radiograph for extraction of 6s
- Grossly carious 16
- Grossly carious 26
- Carious 36 and 46
Supernumerary inverted conical in maxillary midline
Can see furcation of 47 – good sign for 46 extraction – will close the gap
- Remember 5 uses mesial aspect 6s root to bump against and erupt
- Here 45 is rather vertical so if remove 46 teeth will likely come up OK
- If was distally inclined, then could be issue – drift distally – spacing in buccal segments or impact 7s
Signs 8s developing
This case – all 4 6s extracted – likely under GA, may also remove supernumerary tooth too
- Work with parents
- Diet issue and OHI needed
- Need more regular check ups
different types of crossbite
anterior and posterior
unilateral or bilateral
what type of cross bite are ortho concerned with
unilateral cross bite - may interfere with way mandible is closing
how to assess if posterior unilateral crossbite needs interceptive orthodontics?
displacement on closure?
- IOTN
>2mm
TREAT
appliance for treating posterior unilateral cross bite which is causing displacement greater than 2mm
- Active –* midline screw
- Retentive -* Adam’s clasp on 4s and 6s
- Anchorage -*
- Baseplate –* PMMA with posterior bite planes
Wear 24/7
Turn screw ¼ once Sunday and once
how long does posterior crossbite take to correct
6-9 months to correct
but retention of inactivated device for 3 months at night to prevent relapse
tend to OVERCORRECT
- posterior bite planes
- centrelines now coinceident after tx - weren’t before tx
- due to mandibular displacement
- uniformly narrow maxilla - widen with screw - to remove displacement
- centrelines now coinceident after tx - weren’t before tx
when to treat anterior unilateral cross bites
if causing displacment
tend to treat early (when 2s through) with URA
anteriot unilateral cross bites can cause
- uneven wear on incisal edge (chisel like)
- lower incisor is pushed forward - gingival recession (slightly out alveolar bone)
URA for anterior unilateral crossbite
- Active –* Z spring on 12
- Retentive -* Doubles Adam’s clasp on Es and 6s and Adam’s clasp on 11 (can be bulky – use southend, or used 6s and Ds)
- Anchorage -*
- Baseplate –* self cure PMMA with posterior biteplanes
Pt needs to disclude so can push the tooth forward
ALL CROSSBITES NEED
- Simple easy treatment – just tipping one tooth
- Quick
all appliances for unilateral crossbite tx need
posterior bite plane
pt needs to disclude so can push the tooth forward
cross bite correction stability
Anterior
- Overbite
- if good won’t relapse despite growth (upper incisors in front of lower)
Posterior
- 50% relapse
habits cauing malocclusion issues
thumb or dummy sucking
impact of thumb/dummy sucking
- Proclined upper incisors
- retroclined lower incisors
- Asymmetric AOB or reduced OB
- Can tell which thumb with side
- hyperkeratotic pad on thumb too
- Unilater posterior crossbite
- Tendency for upper arch to be narrow
- bucal segment teeth meet edge-to-edge pt displaced one way or the other
- Tendency for upper arch to be narrow
superimposed on genetic makeup of pt – increase OJ etc
when do affects of habit sucking become increased
longer it is a habit
esp post 5 years as beginning to enter mixed dentition phase
thumb sucking tends to persist longer than dummy sucking - peer pressure, parents influence
interceptive orthodontics deterrants for habits (thumb, dummy sucking)
2 options
removable appliances
- double adam’s on Es and 6s
- goal post – behind anterior to remind pt thumb shouldn’t be there
- need pt to be determined – only 2-3 months
Fixed habit breakers (top and bottom)
- Reminder pt shouldn’t be sucking there thumb
can effects of thumb/dummy sucking be reversed?
Give up ASAP and teeth will erupt into normal position
Within 3 years of eruption! (<10 years)
possible issues for interceptive orthodontic tx in late mixed dentition (4)
- Retained deciduous teeth
- Infra-occluded deciduous teeth
- Canines
- Overjets
issue with retained deciduous teeth
permanent teeth pushed buccally as primary teeth still present (lingual)
how to tx retained deciduous teeth in late mixed dentition
take out deciduous teeth as soon as
permanent teeth can drift in eruption but if fully erupted need appliance
infra-occluded deciduous teeth
prevalence
- 10%
- Lowers > uppers
what are infra-occluded deciduous teeth?
a.k.a submerging teeth
but aren’t - everything else is growing up around it
can be ankylosed to bone - no vertical bony development around it
diagnosis of infra-occluded decdiduos teeth
percussion - dull craked cup sound
radiographs
management of infra-occluded permanent teeth depends on
if permanent successor present or not
management for infra occluded deciduous tooth if permanent successor present
observe 1 year - should exfoliate normally
management of infra-occluded deciduous tooth if no successor present
extract (when 1mm crown is showing)
normal development of upper canines (3 facts)
- Development palatal
- Migrate and lie labial and distal to root apex of upper laterals
- 90% palpable by 11 years
- Ugly duckling stage*
- Upper laterals distally tipped – good sign*
3 canine checks
visual
palpate (pinkies best - feel for bulge)
radiographs
3 things to be considering when delayed eruption/ectopic position of canines
- Should palpate by 11 years
- Assess position of upper canines from 10 years onwards
- Mobile C’s (canine resorbing root), symmetry
what age should radiographs be taken if unable to palpate canines
11 years
Generally, OPT and anterior maxillary occlusal or PA
(can do CBCT but rare due to dose)
what parallax shift is used here
horizontal
SLOB - lingual
ectopic maxillary canines can cause resorption of
central incisors in 15%
lateral incisors in 34%
if extract a deciduous canine what action needs to be taken
balance with other side of arch to prevent midline shift
what factors impact success of canine extractions for interceptive ortho
work till the age of 13 years with reasonable chance of success
- Depend on high canine is
- How much adjacent incisor it overlaps
- (cross midline lateral – cross more than 1/2)
benefit of interceptive extraction of canines
avoid 2-3 years ortho tx (costs)
1-2% of population - relatively common
success rate of interceptive canine extraction depending on how much lateral incisor it overlaps
doesn’t cross midline - 90% success
cross midline - 60% (still good - better than coin toss)
what is the prime age for interceptive extraction of cs
10 -13 years
too late - simple intervention not available
positio of canines and tx option
- Palatal ectopic upper canines (both)*
- Quite significant ectopic
- Interceptive Extraction cs – large benefit – straightened up canine and come done in line – save to NHS*
impact of extraction of Cs on space
- Rapid maxillary expansion (RME)
- High pull headgear
Get even higher success rates possibly
reverse overjet
lower teeth biting in front of uppers
Class III
3 causes of reverse OJ
- dental/skeletal/combination
- refer for advice early
- management
assessment of reverse overject (class III)
- able to get Edge to edge?
- Incisor angulations?
- Uppers less than 120
- Lowers greater than 80
Scope to tip
- Limits for class III camouflage – getting class I teeth whilst accepting skeletal issues
incisor angluation needed to use class III camoflage in reverse OJ
upper less than 120
lowers greater than 80
If at 120 and 80 - no room to tip really
effect of time on class III relationship
growth emphasises issue
interceptive orthodontic tx options for class III (2)
- growth modification
- camouflage RA
growth concern with interceptive orthodontic class III tx
be wary
nearly into class I at end of tx
but mandible contiued to grow and back into class III
don’t want to have to repeat tx - wary in acting as may continue to grow
class III growth modification options (3)
- functional appliances
- Functional regulator (FR)
- Frankel (FR) III
- Buccal shields
- Pelots
- Tight lower labial bow
- Spring to procline ULS –
- maxillary protraction
- removable appliances
- z spring
- screw section
funtional appliance
action
evaluation for class III growth mod
- Change soft tissue environment so teeth can move in right direction*
- Hard to wear, expensive – low success rate*
maxillary protraction for Class III growth modification
Reverse pull headgear with facemask
- down and forwards
- Can be with rapid maxillary expansion
Under 10
Quick tx but carries forward into subsequent growth
- 70% success
- 90+% success
removable appliance features for Class III orthodontic tx
z spring
screw section
increased Overjet
class II div 1
causes of increase OJ
dental/skeletal (mandibular retromaphia)/combination
3 impacts of increase OJ
appearance
function
risk of trauam - incompetent lips
IOTN assessment for increased OJ
measure overjet using a ruler
- >6mm 4a
- >9mm 5a
interceptive ortho for class II
growth modification
2 options
functional appliances
- headgear to restrict maxillary forward growth*
- Unacceptable mostly now
functional appliances for class II
impact due to success
huge difference for pt - Teasing
- 75% dental – tipping back UIs and proclination Lis
- 25% skeletal – growth promotion in lower and restriction in upper
functional appliances for Class II
method of action
Harness muscles forces
- promote mandibular growth,
- restrict maxillary growth,
tip lower teeth forward and top teeth back
80% have mandibular retromaphia – so promoting growth good
what types of functional appliances are these (for class II)
All single block
Bar top left – twin block appliance
- 2 individual components come together and pt posture forward
Twin block has 80% success compared to 30% of single so more likely to be worn
describe malocclusion
ideal tx option?
Class II div 1 malocclusion
- Mixed dentition
- Large OJ
- Incompetent lips
- Retromaphic mandible
Ideal candidate for functional
discuss if these lat ceph findings mean this pt can be tx with functional appliance interceptive orthodontics
class II div 1
- ANB 6 = moderate group
- Upper incisors = 130 normally 110 so scope to retrocline them back
- Lower incisors = 91 OK don’t want to procline them more
after
- Profile and lip competence improved despite LI inc proclination
spacing in primary dentition is
OK
>6mm will lead to no crowding in permanent
what to do if unerupted incisors?
radiograph
remove deciduous and obstruction
ensure space for them
observe
balance Cs?
good
not critical (can affect midline – can be fixed later)
carious lower 6s management?
take upper – despite if healthy
unilateral cross bite management
IOTN displacment -> YES needs tx
when should habits be stopped at the latest in order for chance of normal dental development
9 years
infra-occluded deciduous deciduous tooth with successor management
wait and observe for 1 year
infra-occluded deciduous tooth with no successor
extract when only 1mm tooth showing
when to palpate for canines
9-10 years
-ve overjet management
growth
camouflage - correct teeth, accept skeletal
+ve overjet interceptive management
functional appliance
