2010 RWISO Journal - Roth Williams International Society of ...

Figure 72
Figure 73 Supposition: The side arm contacts the skin.
Figure 74 Supposition: The side arm is separated
3 mm from the skin. The hinge point is measured
at level of entrance of the clamp hole.
the skin. In fact, this does not actually happen in clinical
practice, because we always push the side arm onto the skin
to fasten the upper frame to the head. If, however, we assume
3 mm of separation, this means that the flag table will be 6.5
mm away from the skin, and the hinge point locator clamp
will be attached to the flag table (Figure 74).
In this example (Figure 74) the thickness of the hinge
axis clamp is 5.75 mm; the distance from the skin to the
inner surface of the flag table is 6.5 mm; the distance from
the skin to the outer surface of the flag table is 11 mm; the
distance from the left condyle to the skin on the right side of
is 110 + 15 mm; and the distance from the left condyle to the
inner surface of the flag table is 110 + 15 + 6.5 mm. This is
indicated by the yellow arrow.
The measurement error at the position indicated by the
arrow is calculated as follows:
•
Y is the measurement error on the inner surface of the
flag table. The amount of error is 0.20 mm (Figure 75).
Figure 75 Y is the measurement error on the inner surface
of the flag table. The amount is 0.20 mm.
•
The measurement error at the inner entrance of the
hinge axis clamp increases slightly (Figure 76).
Figure 76 Supposition: The side arm is separated 3 mm
from the skin. The hinge point is measured at
level of entrance of the clamp hole.
RWISO Journal | September 2010
33