Page 99 - REMOVABLE ORTHODONTIC APPLIANCES

Chairside management 91
Figure 10.9 Adjustment to bring arrowhead into
contact with the tooth.

Adjustments to the acrylic springs the labial wires, loops and buccal
springs should be adjusted if necessary so that
On occasion, slight initial trimming may be
necessary to allow insertion, but beyond this, they lie at the correct height and do not trau-
matize the cheeks, lips and gingivae.
some adjustments to the baseplate may also be
necessary. The acrylic will need to be trimmed During the first few days with a new appli-
to permit active tooth movement. This is of ance the patient has to get used to inserting it
great importance but is frequently overlooked. correctly, must adapt to its presence and
The appliance should be inspected in situ to perhaps put up with a mild degree of discom-
ensure that no part of the acrylic contacts the fort. It is sensible to provide only very hght acti-
tooth to be moved and that this tooth move- vation so that the appliance is self-activating
ment will not result in contact before the next and the springs cannot readily slip into the
visit. It is also sensible to trim the acrylic so that wrong position. This will imply activation of
any desired passive movement might occur, for about 1 mm for a palatal spring and 0.5 mm for
example to permit a buccaliy placed canine to a 0.7 mm buccal spring. It will often not be
move into line as a premolar is being retracted. possible to position a palatal spring close to the
gingival margin at the first visit because of
contact with the neighbouring tooth. This can
be corrected at the next visit when some move-
Bite planes
ment should have taken place.
Any excessive thickness may need to be
reduced and bite planes adjusted to give even
contacts. In the case of posterior bite planes,
careful trimming will usually be necessary to Demonstration to the patient
ensure that the occlusion is evenly distributed. • Show the patient the appliance in the mouth
An anterior bite plane will need to be under- using a mirror, demonstrating how it should
mined on an appliance designed to reduce an be inserted and removed. (During fitting,
overjet before activating the labial spring. any anterior clasp on the incisors will gener-
ally be engaged and the position of the
springs checked before upward pressure is
Adjustment to active wirework applied to the palatal acrylic with a finger or
The appliance should now be easy to fit and thumb (Figure 10.10). Removal should be
have adequate retention. Before activating achieved by exerting finger pressure on the