EFFICACY OF TEMPORARY FIXED RETENTION FOLLOWING ...

sets of records for each of 18 untreated patients. He also noted lingual
uprighting of the mandibular incisors in association with late growth changes,
and concluded that anterior crowding can be influenced by posttreatment facial
growth.
Shields et al. (1985) assessed 54 first-premolar extraction cases at least 10
years posttreatment to determine whether there were statistically significant
correlations between cephalometric variables and the observed posttreatment
change in Incisor Irregularity. They concluded that no cephalometric
parameters, such as horizontal and vertical growth amounts were found to show
any statistical association with changes in posttreatment mandibular anterior
irregularity. In addition, pre- and posttreatment changes such as incisor position
and facial growth were poor predictors of stability. Only a slight tendency was
found for incisor inclination to return toward the pretreatment value during the
postretention period.
According to Huckaba (1952), greater stability is seen in cases who were
treated during periods of active growth and that growth accounts for many of
the changes seen following orthodontic treatment. Based on this premise, Riedel
(1960) suggested that corrections carried out during periods of growth are less
likely to relapse; therefore, orthodontic treatment should be started at the earliest
possible age. However, Riedel (p 185) goes on to admit that, “There seems to be
little positive evidence to substantiate this statement.”
Harris et al. (1994) analyzed the effects of age on postorthodontic stability
by comparing two samples five years out of treatment: 22 patients treated
during adolescence and 23 patients treated during adulthood. All patients were
treated by a single practitioner, had four premolars extracted, and were placed
on identical retention protocols – maxillary Hawley and mandibular fixed
lingual retainer. Posttreatment stability existed in both groups, but for different
reasons. In the adult group, little posttreatment skeletal or dental change
occurred. In the adolescent group, continued midface and mandibular growth
occurred which compensated for any unfavorable mesial drift of the dentition.
The conclusion drawn from this study was that, “Orthodontic corrections in
adults were found to be at least as stable as those in the conventional adolescent
patient” (p 25).
A retrospective longitudinal study was undertaken by Driscoll-Gilliland,
Buschang and Behrents (2001) to compare the skeletal and dental changes seen in
orthodontically treated patients with those in a comparable untreated group.
The purpose was to evaluate the relationship between skeletal changes and
mandibular incisor crowding. Results of the study were based on cephalograms
and dental casts of 44 untreated subjects from the Broadbent-Bolton Growth
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