BDS3 interceptive ortho important Flashcards
what is definition of interceptive ortho?
Any procedure that will reduce or eliminate the severity of a developing malocclusion’
how is space gained to accomomadate larger anterior teeth of the permanent dentition?
- increase in the intercanine width through lateral growht of jaws
- upper incisors erupting onto a wider arc
- leeway space
what is leeway space of upper arch?
primary canine + first molar + second molar
minus
permanent canine + first premolar + second premolar
=
1 to 1.5mm
what is leeway space of lower arch?
primary canine + 1st molar + 2nd molar
minus
permanent canine + 1st premolar + 2nd premolar
=
2 to 2.5mm
what is diastema?
gap in between teeth
what are the management options if a first permanent molar gets stuck between the ‘e’ and fails to fully erupt?
- If patient <7years wait 6 months (90% self correct)
- Orthodontic Separator
- Attempt to distalise the first molar
- Extract E
- Distal disking of ‘e’
what is case assessment of unerupted central incisors?
- Case history –esp. regarding trauma
- palpate labially and palatally
- if retained Primary tooth present, Is primary mobile? Is it discoloured ?
- Radiograph (AOM/ Periapical)
how to deal with unerupted central incisor?
- Remove primary teeth & Supernumeraries
- Create space/maintain space
- Monitor for 12 months
If patient < 9 years (immature root apex)
Still fails to erupt? OR patient >9 years (mature root apex)
- Monitor for 12 months
- Expose/bond gold chain and apply orthodontic traction
what does early loss of decidous teeth cause?
localised crowding
how does the effect of localised crowding from early loss of deciduous teeth vry?
- Degree of crowding already present
- Age
- Which arch? Which tooth?
what is a balancing extraction and why?
o Balancing Extraction = removal of a tooth from the opposite side of the same arch
Why?
To maintain the position of the dental centreline (preserve symmetry)
what is a compensating extraction and why?
o Compensating Extraction = removal of a tooth from the opposing quadrant
Why?
To maintain the buccal occlusion.
what is management of early loss of A’s and B’s?
little impact
don’t balance or compensate
what is management of early loss of C’s
balance
what is management of early loss of D’s?
small CL. shift, balance under GA?
what is management of early loss of E’s
tend not to balance
major space loss
upper>lower
Consider space maintainer- this main one
describe compensating for a C?
if you remove an upper C you gotta remove a lower C
what is a type of removable space maintainer?
passive URA
what are typical components of passive URA?
o Retention e.g. clasp UR6,UL6 (0.7mmHSSW) Labial bow UR3 to UL3 (0.7mmHSSW) OR Southend clasp (0.7mmHSSW)
o Baseplate – extend acrylic around teeth to prevent unwanted mesial drift
o +/-Mesial Stop (0.6mm HSSW) on individual teeth if required
what would factors of extracting carious 6’s be?
o Age of patient / stage of dental development
o Degree of crowding
o Malocclusion type
when would the most ideal result of extracting carious 6’s?
o 7’s bifurcation calcifying
o 8’s present
o Class 1 av/reduced OB
o Moderate lower crowding
o Mild/moderate upper crowding
what are general rules for extracting class 1 6’s?
o If extracting lower take upper
o Don’t balance with sound tooth. Don’t balance if well aligned or spaced.
o If extracting upper don’tneed to take lower.
what are general rules for extracting class 1 6’s?
o If extracting lower take upper
o Don’t balance with sound tooth. Don’t balance if well aligned or spaced.
o If extracting upper don’tneed to take lower.
how to clinically assess anterior cross-bites?
- displacement
- mobility of lower incisor
- tooth wear
- gingival recession
what are types of cross bite?
- Posterior Unilateral Crossbites
- posterior cross-bites
- anterior cross-bites
when is treatment of posterior unilateral cross bite needed?
only if it shifts midline by >2mm. so if pt bites down and between the motion to RCP he laterally shifts >2mm then thats treatment needed
what is digit habit management?
- positive reinforcement
- bitter-tasting nail varnish
- glove on hand, elastoplast
- habit breaker appliance (habit deterrent) - fixed or removable
breakdown interceptive ortho and what you do and for what?
-unerupted incisors - remove ob/space/obs
- impacted 6’s - observe 6/12 or intercept
- balance c’s - but not critical
- carious lower 6’s - take upper
- uni cross bites - IOTN displacement?
- habits - stop before 9
what can be used to help fix habits?
detterents apliance
what is the aetiology of infra occluding teeth?
ankylosis of primary tooth. surrounding alveolar bone continues to grow. primary tooth gets left behind?
what is the diagnosis of infra occluding teeth?
- perucssion
- check for mobility
- radiographs
what do you assess radiograph for with infra occlusion?
- presence /absence of successor
- Ankylosis of primary tooth (no PDL space/no clear lamina dura)
- Root resorption of primary
what do you do if permanent successor is present when dealing with infra occlusion?
- Monitor 6-12 months
- Extract if primary tooth is below the interproximal contact point
- Consider extraction if root formation of successor near completion
- If extract …..maintain space
- Be more vigilant in upper arch
how long do you monitor permanent successor present for infra occlusion?
6- 12months
when do you extract if permanent successor is present when dealing with infra occlusion? and what do you do after if you extract?
- Extract if primary tooth is below the interproximal contact point
- Consider extraction if root formation of successor near completion
- If extract …..maintain space
what are risks of doing nothing if permanent successor is present when dealing with infra occlusion?
- Permanent successor can become more ectopic
- Infra-occlusion worsens with tipping of adjacent teeth - primary tooth becomes inaccessible for extraction
- Caries and periodontal disease
when does infra occlusion worsen?
- Infra-occlusion worsens with tipping of adjacent teeth - primary tooth becomes inaccessible for extraction
when dealing with infra occlusion what does treatment plan depend on if permanent successor is absent?
o degree of crowding
o degree of infra-occlusion
o any other features of malocclusion ?
when dealing with infra occlusion what do you do if you extract when permanent successor is absent?
plan space mangement
o Either maintain space for prosthetic tooth
o Reduce space to one premolar unit ( requires fixed appliance)
o Close space ( fixed appliance)
in delayed eruption when should you assess position of upper canines?
- Assess position of upper canines from (9 to) 10 years onwards
- Should palpate by 11 years
- Mobile C’s, symmetry
- Angulation of lateral incisors
when is extraction fo the c’s likely to be successful?
o Patient is age between 10-13 years
o The canine is distal to the midline of the upper lateral incisor
o There is sufficient space available
o The canine is less than 55 degrees to mid-sagittal plane
what are the risks of doing nothing when dealing with ectopic primary maxillary canines?
o Permanent successor can become more ectopic
o Permanent canine then fails to erupt (Impacted Canine)
o Risk of root resorption of adjacent teeth
o Risk of root resorption of canine crown (lower risk)
o Risk of cyst formation around canine (rare)
o Permanent canine can become ankylosed (incidence tends to increase with age)
what are the options for growth modification for interceptive treatment of class III?
- Protraction headgear +/- RME (rapid maxillary expansion)
- Functional appliances e.g.Reverse Twin Block / Frankel III
when is growth modification in class III most successful?
- skeletal I or only mild class III
- maxillary retrusion
- anterior displacement on closing
- avergae or reduced lower face height
- patient age 8-10 years
what are possible environmental factors of malocclusion?
masticatory muscles
mouth breathing
head posture
why tx increased overjet early?
- Risk of trauma - incompetent lips
- Appearance – bullying/ patient self- esteem
- More difficult to achieve correction once patient stopped growing
