Interceptive Ortho Seminar Flashcards
What is meant by interceptive treatment?
Prevent malocclusion occurring or alleviate issues
What issues can cross bite in upper central region causing mandibular displacement cause?
- trauma and tooth wear
- Can cause mobility to lowers
- Can result in lower incisor being pushed labially in bone causing recession
- Predisposal to TMD
What is a screw section used for?
Proclining more than one incisor in crossbite
What is a C Clasp? When is it used?
Looks like half a south-end class (curves around gingival margin)
-> good for mobile deciduous teeth
What factors contribute to correction of an anterior crossbite?
- Good OB- suggests good chance of stability (stops tooth moving back)
- Tooth is retroclined- scope to procline it
- Space present
- Patient can achieve edge to edge (good prognostic indicator for this and class III)
Why is maxillary expansion helpful in patients who have unilateral crossbite?
Can prevent permanent teeth erupting into crossbite
What is the mechanism of narrowing of the arch in patients with a sucking habit?
Tongue is depressed, negative pressure created by sucking
-> effects occur on dentition and growth in width of maxilla
What causes mandibular displacement in patients with sucking habit?
Arch widths are different due to sucking habit
-> unilateral crossbite caused by uppers occluding with teeth on only one side in lower wider arch
-> displacement occurs to achieve interdigitation on one side
What are the causes of AOB?
Endogenous tongue thrust
Genetics- increased lower face height
Trauma- intrusion of incisors
MD/CP- lack of muscle tone in face can result in patients keeping mouth open all the time and altering skeletal pattern
Why do we encourage patient to stop sucking habit by 8-10 years?
Root formation is still occurring meaning there is a lot of eruptive potential
-> stopping habit by this age can mean AOB can spontaneously correct (encourage parent and patient)
What can be done to fix a digit sucking habit?
- Nail varnish
- Try a glove over hand at night
- Plasters on fingers
- Fixed habit breaker- palatal arch with tongue rake
- Removable habit breaker- passive, cribs 6s, south end clasp, palatal goal post (could combine this with URA that would also expand arch)
After fixing allow 6 months before intervention to allow spontaneous closure
What are the treatment options for AOB?
Fixed upper and lower appliance- intrude molars, extrude incisors (may require extractions)
-> TAD in maxilla if >2mm- helps with intrusion (give absolute anchorage)
Orthognathic surgey- if AOB >4mm
- Maxillary impaction- tip maxilla (front tipped towards)
- Lefort 1 osteotomy
What sound is made by percussion of infra-occluded molar?
Cup sound
What is the mechanism by which infra-occlusion occurs?
Tooth becomes ankylosed (fused) to bone and everything else grows around it
-> gives appearance of sinking
What are the causes of ankylosis?
- Trauma
- Infection
- Missing successor
What radiographs are taken for Infra-occluded teeth?
OPT
PA
What are the management options for infra-occluded teeth?
Do nothing and monitor with photographs and study models (if slight delay, AND tooth has not dropped below contact point of 6)
Extraction of E with space maintainer to prevent drift (band and loop/URA with distal stop)
-> URA worn full time until tip of 5s are erupting (then just at night)
-> Can take up to 12 months
If no sign of eruption at 12 months- radiograph
If no successor- consider retaining E and building up
-> urgently refer for restorative opinion
What are the risks of doing nothing with infra-occluded teeth?
Tipping of teeth leading to surgical extraction
What is different about infra-occluded teeth in lower arch?
They don’t submerge as fast
What are the factors influencing whether a first permanent molar of poor prognosis is extracted in a child?
- Stage of dental development- bifurcation of lower 7s forming (as uppers are more likely to close space)
- 8s present (can’t guarantee eruption)
- Age and cooperation
- Is patient likely to return
- Will GA be required- radical treatment plans
- Crowding
- Malocclusion- class 2 div 1 will likely require extraction (you may want to time this to help with orthodontic treatment)
When should we compensate extraction of an FPM in children?
If lower molar- compensate in upper to prevent over-eruption (check it is likely to be unopposed)
-> Upper 6 overeruption can stop eruption of lower 7s
If forced extraction of upper- don’t compensate
What is balancing?
Removing contralateral tooth
When is balancing FPMs considered?
Not if other tooth is healthy
BUT
In the lower arch only, in class I cases when moderately crowded in the buccal segments and if contra-lateral first molar is of doubtful prognosis, consider balancing
What are the results of early loss of deciduous teeth?
Can lead to space loss and precipitate crowding
Can delay eruption of permanent successor
At what stage does removal of primary tooth speed up eruption of successor?
If more than half of the root has developed
What can delayed loss of deciduous teeth result in?
Ectopic successor
Failure of eruption
What are the effect of early removal of FPMs?
Distal drifting of 4/5s in lower arch (can deepen OB)
Too late- mesial tipping of 7 (difficult to clean- perio pocket can develop here)
-> space maintain
How do we manage forced loss of teeth in deciduous dentition?
Consider balancing Cs to maintain centre line in crowded dentition
No compensation
If extracting D/Es- space maintain
What are the factors which influence space loss when primary teeth are extracted?
Patient age at time of loss
Which arch tooth belongs to
Degree of crowding present
What are the causes of impacted 6s?
Severe crowding
Abnormal morphology of E- enlarged
What are the risks of impacted 6s?
Caries
What are the treatment options for impacted 6s?
If not severe- consider extraction of E
Disimpact 6- place ortho separator/brass wire for a week (check for signs of eruption)
Use appliance to push 6 back- difficult as it is partially erupted- bond fixed appliance component to 6 to distalise it using PFS
Distal discing of Es- give more space for eruption (can result in a bit of crowding)
Consider pre-molar extractions to alleviate crowding
What are the interceptive measures used in hypodontia ?
Refer as soon as identify
-> Combined Ortho/Paeds monitoring
Guidance of eruption of permanent teeth
Restorative treatment alone
-> Build-ups
Early orthodontics to improve aesthetics
-> Closure of diastema
What is dens in dente? How is it managed?
enamel folds back in on itself (can end up with communication between oral cavity and pulp- difficult RCT, poor prognosis)
- Take deciduous teeth out to allow this to erupt (prevents 3 from deflecting and going palatal)
What situations in orthodontics may require interception?
- Cases suitable for growth modification :
Class II Div I case with Increased overjet in the mixed dentition
Mild Skeletal Class III with Class III incisors in mixed dentition
Deep overbites (utilise eruption potential) - Anterior Crossbite
- Posterior cross bite
- Digit-sucking habit
- Impacted teeth – Canines
- Impacted teeth – First permanent molars
- Unerupted central incisors
- Missing upper lateral incisors
- Infra-occluded second deciduous molars
- First permanent molars of poor prognosis
- Upper midline diastema in the mixed dentition
- Early loss or delayed loss of deciduous teeth (may also be included within some of the above categories)
- Developing crowding suitable for space maintenance
- Transposed teeth
