<p><strong>SOLUTION:</strong>&nbsp;Lack of retention with removable orthodontic appliances is expected during the first several weeks of treatment while the patient is adjusting to the appliance. For this reason, most doctors will not activate the appliance in this initial period. It should then seat comfortably without displacement, thus assuring patient compliance.</p>

<p>When the orthodontic forces exerted are greater than the ability of the clasp to retain the appliance, the force is reduced. A series of light pressure adjustments may be required. Lack of movement on a particular case indicates the need for a more extended treatment period rather than increased force. For this reason, the forces can usually be reduced to improve retention with out compromising appliance effectiveness.</p>

<p>On younger patients, short clinical crowns and minimal undercuts on permanent and primary molars often prevent retentive clasps from being applied effectively even with light forces. In this case, artificial undercuts can be created for the clasp to &ldquo;grasp&rdquo;. One such method involves disking a buccal undercut into the primary molar at the gingival border. If the primary teeth are expected to exfoliate shortly, undercuts on permanent molars are created by cementing a band with a buccal tube or applying a small portion of bonding material to the buccal of the tooth. The clasp can now be adjusted to take advantage of this new undercut to retain the appliance effectively during treatment.</p>

<p>Retention problems that occur only after months of treatment are usually an indication that the appliance no longer represents the current condition of the case. In younger patients, changes are occurring that require appliance adjustments to keep place with both the orthodontic movement and natural development. This is particularly evident in arch development appliances like the Schwartz Expander. As the palatal vault takes on a more normal shape from the deep vault often seen in the initial stages, acrylic is when the appliance can not be adjusted sufficiently to regain retention, a new model is taken and the appliance and model are sent to the lab for revamp to the current condition. A Temporary Retainer can be placed to prevent relapse until the updated appliance returns (see Problems/Solutions-Relapse/Temporary Retainers).</p>
