Limitations and current uses of removable appliances Flashcards
Which movement does a removable appliance have on teeth?
It TIPs them
What are the potential problems if you just tip teeth?
- Aesthetics
- Dental Health
- Occlusal fit
- (its okay within limits - i.e. can tip a mesial proclaimed tooth distally)
What are the issues with having removable appliances in the lower arch?
- Less undercut for retention
- Less buccal sulcus or springs (without enough wire = insufficient flexibility to move the tooth)
- Tongue severely limits lingual space for springs
Which limitations are there (due to the tipping action)?
- Mesio-distal in the buccal segments
- labio-lingual in Class II
- labio-lingual in Class III
- Mesio-distal in labial segments
What are the limitations of removable appliances?
- Tipping
- Lower arch
- vertical movements
- inter arch elastics
- precision
- rotations
- multiple tooth movements
What are the current use of removable appliances?
- Space maintenance
- Retainers
- Tooth over the bite
- Bite opening
- Expansion
- Other simple tooth movements
- (functional appliances)
How can removable appliances act as a space retainer?
How can removable appliances be used as removable retainers?
n.b. the acrylic increases the retaining ability
What are the good points of removable retainers?
- * all the teeth can be retained
- * partial withdrawal possible
- * less dental health hazard
- * oral hygiene
- * missing teeth can be replaced
- * responsibility of the patient
What are the weak points of removable retainers?
- * rotations
- * anterior diastemas
- * vertical tooth position
- * need to be worn
If you have a fixed upper retainer what should you have too?
A removable one (behind upper teeth is where your lower teeth bite)
What are vacuum formed retainers (VFR)?
How are removable appliances useful for teeth over the bite?
Can move one or two teeth only
e.g. an upright upper incisor and mandibular displacement using Z and T springs
What are bite planes?
pieces of acrylic that stand behind the teeth so there is sufficient gap between upper and lower teeth, can be anterior or posterior
What are the advantages of the acrylic baseplate?
- Can provide anterior and posterior bite planes
- Can accommodate a screw
- Give some anchorage from the plate
Whats a twin block functional appliance?
n.b. two separate blocks, one attached to upper, the other attached to the lower = used to correct increased oversets (sticking out upper teeth), moves all teeth
