EFFICACY OF TEMPORARY FIXED RETENTION FOLLOWING ...

decreased in both arches during the recall period and that degree of Incisor
Irregularity at pretreatment was not predictive of instability over the long-term
recall period.
Sadowsky and Sakols (1982) evaluated the long-term stability of 96
patients who had been treated between 12 and 35 years previously. Their
purpose was to identify variables that fell outside the ideal range of variation at
long-term recall. Similar to the present study, this sample also revealed an
acceptable amount of incisor stability at the long-term with an average of 2.8 mm
of Incisor Irregularity. However, the authors of this study acknowledged that
any possible influence of length of retention was not considered.
Another study by Sadowsky et al. (1994) consisted of a sample of 22
orthodontically treated cases who were evaluated for long-term stability an
average of 14.5 years posttreatment. The purpose was to evaluate the long-term
stability of cases treated by a single practitioner whose policy was to use longterm
fixed retention in the mandibular arch. These patients were retained with a
mandibular fixed lingual retainer for an average of 8.4 years, but were without
retainers for a minimum of 5 years prior to evaluation. Incisor irregularity was
similar to the fixed retention group at the start of treatment (5.2 mm versus 5.4
mm), at the end of treatment (1.0 mm versus 0.5), and at the recall stage it was
(2.4 mm versus 1.9 mm). Sadowsky et al. concluded that less relapse (than other
studies have documented) occurred in cases at 5 years postretention when fixed
retention was prolonged to age 18. The findings of the present study support
this notion; yet also demonstrate an equivalent long-term stability in a similar
sample of patients following retention with removable retainers only. Sadowsky
et al. acknowledged the importance of the long-term recall period, as well as the
shortcomings of their small sample size, but proposed that the increased stability
noted in their research may reflect the prolonged mandibular fixed retention.
Even though the present study, with a long-term recall period of ~ 14 years
postretention, and a fixed retainer sample size of 69 cases, demonstrates
equivalent statistical stability for mandibular incisors as reported by Sadowsky et
al. (1994), it is difficult to attribute this increased degree of stability to prolonged
fixed retention, because clinically similar degrees of stability were also
demonstrated in a sample of 97 cases retained only by removable retainers.
In a study of 32 patients treated by the same practitioner, who had been
out of retention for a minimum of 5 years, Boley et al. (2003) documented
acceptable stability of mandibular incisors at an average of 15 years
posttreatment (11.7 years postretention). Mean Incisor Irregularity at the longterm
recall was 2.6 mm; however, this sample had a much greater degree of
Incisor Irregularity at pretreatment than most previous studies ( x = 8.1 mm).
Similar to the present study, there was a much greater percentage of cases with
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