Page 93 - REMOVABLE ORTHODONTIC APPLIANCES

Class III malocclusions 85
Retention by the addition of cold-cured acrylic, either to
cover palatal springs and contact the incisors,
The necessary length of retention will depend or to lock a screw into the open position.
upon the depth of overbite at the completion of In some cases, particularly a lingually occlud-
treatment. A corrected incisor crossbite with ing lateral incisor, it is possible to increase the
increased overbite at the end of treatment may overbite and to reduce reliance on the retainers
require little or no retention. The first stage of by adding composite to the incisal edge of the
retention in most cases will be to remove the incisor to help maintain the corrected overjet.
molar capping. At the following visit the
patient is instructed to wear the appliance on a
nights-only basis for a further 2 months. Further reading
Where the overbite is reduced, retention
should be maintained for longer. If a screw or Nerder, P.H., Bakke, M.. Solow. B. (1999) The functional
springs have been used to correct the incisors shift of the mandible in unilateral posterior crossbite.
and the overbite is reduced, it is often advisable European Journal of Orthodontics. 21: 155-166
to make a separate retainer such as a conven- Ninou, S., Stephens, C D . (1994) The early treatment of
tional appliance with a 'U' loop labial bow - posterior crossbite - current understanding of continu-
specifically to hold the incisors in their new ing controversies. Dental Update, 21: 420-426
Stephens, CD., Jenkins. C.G.B. (1988) Crown modification
position. Where this seems unnecessary, it is
using composite resin to achieve incisor overbite.
possible to make the previous appliance passive
British Journal of Orthodontics, 4: 121-122.