EFFICACY OF TEMPORARY FIXED RETENTION FOLLOWING ...
EFFICACY OF TEMPORARY FIXED RETENTION FOLLOWING ...
EFFICACY OF TEMPORARY FIXED RETENTION FOLLOWING ...
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final vertical positions. This phase requires substantial patient compliance. The<br />
intent of fixed retention is to maintain an ever-present rigid control, particularly<br />
over the lower incisors, that does not depend on patient compliance. The idea is<br />
that, if fixed retention remains in place for a couple of years, this allows the<br />
periodontal tissues to become reoriented and passive to the new tooth positions<br />
and provide stability to incisors during the period of time when most relapse is<br />
thought to occur (Reitan 1967; Melrose and Millett 1998; Al Yami et al. 1999).<br />
Prolonged fixed retention for a couple of years might also allow fixation of the<br />
incisors until issues of the third molars have been addressed (Bergstrom and<br />
Jensen 1960; Sheneman 1969).<br />
Sample Considerations<br />
The cases used for the present study represent a geographically diverse<br />
sample consisting of records collected from several orthodontic practices in the<br />
United States and Mexico. As noted, all cases were treated with a similar<br />
treatment philosophy. Possible shortcomings of this study might be associated<br />
with the fact that all of the records were voluntarily submitted by orthodontists<br />
in private practice. This collection strategy could allow the orthodontists to<br />
cherrypick their cases and submit cases that they perceived to retain more<br />
satisfactory results. However, this risk is no greater or worse than any other<br />
recall study of this type. We have to rely on the desire and intent of the original<br />
data collection of the International Tweed Foundation, which expressly<br />
requested doctors to submit cases of all quality to allow for a representative<br />
sample of all treatment outcomes. There is no reason to believe this request was<br />
not adhered to. In addition, the overall scarcity of 10 year post-treatment records<br />
tends to minimize this bias, because in most cases, you are lucky to “get what<br />
you can get.” An example of this was documented in the sample protocol of two<br />
studies out of St. Louis (Paquette et al. 1992; Luppanapornlarp and Johnston<br />
1993). Efforts were made to contact each prospective patient five times. Out of<br />
2,500 prospective patients, only 125 actually participated in the two studies. This<br />
recruitment rate of 5% illustrates the difficulty of obtaining long-term samples.<br />
There also is the insurmountable issue of self-selection. It seems likely<br />
that patients with stable (and, thus, esthetic) outcomes would be more willing to<br />
participate in a recall study. Conversely, subjects who were non-cooperative<br />
patients and/or had unstable outcomes might be less enthusiastic about being<br />
reevaluated by their orthodontists since this could leave them open to criticism<br />
by the specialist.<br />
Another issue that is difficult to control is the individual orthodontist’s<br />
commitment to the use of a fixed retainer. Despite the consensus opinion that<br />
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