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