Difficulty Keeping Spring Retainer Appliances in Place
The Spring Retainer is a pre-adjusted appliance intended to improve minor anterior rotations. Pressure is built into the appliance for the desired movement, thus requiring little or no adjustment and minimal chair time. Another advantage of the Spring Retainer is that the active appliance can also serve as a post-treatment retainer, thus making this approach more economical for the patient.
Before the appliance is constructed, a model is prepared by resetting the rotated anteriors into an ideal arch. Resetting teeth on the construction model can include one or more anterior teeth but is usually limited to the four incisors.
The appliance is made to fit this new “perfect arch” with acrylic contacting both the lingual and labial surfaces of all anteriors. A wire “spring” connects these strips of acrylic to the remainder of the appliance and provides the flexibility needed to allow the appliance to seat properly. For space on cases of minor crowding, most doctors will slightly disk or strip the interproximal surfaces. This is usually done at the time the appliance is inserted to assure optimal use of the space.
At the outset, slight discomfort and displacement can be expected for the first week. The appliance should then seat properly. However, when difficulty persists in seating the appliance or the appliance is continually displaced, the teeth may be rotated beyond the ability of the appliance to maintain good anchorage.
To reduce the possibility of displacement, many doctors will prescribe four clasps on the appliance for superior retention; usually consisting of ball clasps interproximally between the bicuspids and adams clasps on both first molars. This is usually sufficient to overcome retention problems when only one or two teeth have been reset on the construction model.
When all four incisors have been reset, the degree to which they can be rotated simultaneously is limited by how far the appliance can “stretch” to seat over these malaligned anteriors. When the amount of rotation is more severe, the four incisors can be reset only partially on initial construction allowing for improvement in stages. Once the initial improvement has been realized, the construction model is modified to reset the teeth to a final ideal arch. The original appliance can be refined and then reinserted for additional movement.
Once movement is complete, the appliance can then be used as a retainer for nine months and is reinserted approximately once each month thereafter, as a “check guide” against relapse, if it is difficult to seat, indefinite nighttime retainer wear is usually indicated.
If you have a case you are considering for treatment,
send models for an appliance outline, detailed correspondence
and laboratory cost estimate at no obligation.
Or, call Paul, Toll Free…