Lec 9 - Facebow Flashcards
IMPORTANT: function of the facebow is to relate the blank cast to the tmj
maxillary
facebow is for fabricating accurate dental restorations based on articulator movements that blank mandibular movements
RESEMBLE, NOT REPLICATE
reference planes/axes for facebow
axis orbital plane, frankfort plane
semi adjustable articulators like the ones we have wont allow us to find the exact location of the blank
hinge axis
arbitrary fascia point located 13 mm anterior to the posterior margin of the tragus on a line from the center of the tragus to the outer canthus of the eye
beyron’s
arbitrary fascia point located 10 mm anterior to the posterior margin of the tragus on a line from the center of the tragus to the outer canthus of the eye
gysi’s
estimated hinge axis is found by using this plane as a reference and uses a blank bow ear insert
frankfort Po-O, spring
hole on the articulator is offset by this much from the estimated hinge axis ear piece
10 mm
this is a geometric determination of errors resulting from arbitrary hinge axis location
weinberg
weinberg terminal hinge axis 5 mm too far posterior and a 3mm thick record produces an error of blank at the second molar during occlusion
.2 mm
provides orientation for maxillary arch with patient’s condyles
facebow transfer
spring bow goes here
in patient’s ears
sm facebow goes here
arbitrary points on face like gysi’s and beyron’s
red cake modeling plastic is used on the blank to get indentations of the teeth in the facebow
bite fork
condylar guidance should be set at blank
30 degrees
