fixed appliances ortho 2 Flashcards
6 keys of normal occlusion
class 1 molar rx crown angulation (roots tipped distally) crown incliniation no rotation in arches tight contacts(no crowding or spacing) flat curve of spee (flat occlusal plane)
degrees of tip
canine 11 degrees
central incisor 5 degrees
tip and torque built into bracket based on the slot
main stages of tx
levelling and alignment
space closure
additional stages
space closure includes
overjet reduction
centreline correction
additional stages includes
overbite correction
cross bite correction
finishing and detailing
initial archwires for stage 1 (alignment and levelling)
round wires
NITi or beta titanium
what are canine lacebacks used for
fit before main arch wire is placed
prevents canine crown moving mesially
posterior teeth can move forward
crossed from 6 to 3
sliding mechanics
NiTi springs (closing coils, from auction hook and canine hook) elastic (power chain or traction ligatures)
types of retainers
removable (acrylic or vacuume formed ie Essix)
(Hawley retainers)
bonded
Hawley retainers acryluc
acrylic labial bow
can add prosthetic teeth on
often have Adams clasps on molars
good when arch has been expanded
vacuum formed retainers esix
more common
bonded retainers
wire bonded to teeth with composite
have to use TP brushes for cleaning inbetween
retention regime
12hrs for 1st yr
alternative nights for 2nd year
gradual withdrawal min 1 night a week indefinitely
unstable result/high relapse potentail
periodontally involved teeth
midline diastomer
severe rotation
teeth out of zone of stability with soft tissues
pericision
cutting of fibres
tries to prevent teeth rotating
takes a long time to remodel
