ORTHO ISCE Flashcards
(31 cards)
what are the muscles of mastication and what are their roles?
Temporalis: raise and retract the mandible
Masseter: primarily elevates the mandible
Medial Pterygoid: elevation and protraction (protrusion) of the mandible
Lateral Pterygoid: opening the mouth and lateral movement of the mandible
what type of movement does a removable appliance bring about?
tipping - by applying pressure at the tip of the tooth
bodily movements
interceptive treatment to move a couple of teeth (in the mixed dentition phase) to plan more comprehensive treatment
what are the components of a removable appliance?
anchorage: baseplate and clasps
active component: screws/ springs/ bows
retentive components: clasps
what instruments are in the orthodontic removable appliance kit?
adams plier
spring forming/ birds beak/ loop forming plier
describe the adams plier?
2 flat ends - can create a 90 degree bend
name the types of clasps for removable appliances?
adams
southend
delta
plint
ball end
why do adams clasps need adjusted?
they can lose retention from being taken in and out of the mouth
name the parts of the adams clasp?
bridge
arrowheads
crossover wire
where do the arrow heads on an adams clasp engage?
proximal undercuts (mesial and distal)
where do southend clasps engage?
cervical undercuts
what is an important feature of the crossover wire of the adams clasp?
ensure it does not interfere with occlusion
what is used to adjust an adams clasp?
can use any pliers
how is an adams clasp adjusted?
move the arrowheads down (vertical) - hold the wire just out of the acrylic
move the arrowheads inwards (horizontal) - hold the wire closest to the arrowhead
(usually only needs vertical)
what type of wire is used for clasps on a removable appliance?
round stainless steel 0.6/0.7mm hard wire
what is the function of the labial bow?
retention or active for proclined incisors/ overjet
what parts of the labial bow are adjusted?
the U loops
when would an extra loop be added to the U loop on a labial bow (Roberts retractor)?
if treatment is over a longer period of time - it is lighter force as longer wire
when is a fitted labial bow used?
retainer after ortho treatment
how is a labial bow activated?
activate the U loop by squeezing/ closing
- hold the back of the U loop with plier and squeeze with thumb to move the bow downwards
- hold the front of the U loop to push the bow upwards
when would a FABP be used?
deep overbite - to create space for molars to supraerupt
what are the components to the formula for spring wire?
F = force
D = deflection
R = radius
L = length
what is the meaning of the formula for springs?
thickness of the wire is proportionate to the force: thinner longer wire is used
why do you want a light force with active springs?
if force to heavy it will exceed capillary pressure = osteoclasts cant get to the tooth and the blood supply is cut
(hylanisation)
what are Z springs used for?
protrusion where there is an anterior crossbite or retroclined incisor
