Abstract:
Proposition: The objective of this study was to evaluate the relapse of mandibular
anterior crowding in cases treated extraction of a mandibular incisor. Methods: The
sample consisted of initial, final and control study models and intraoral photographs
of 16 subjects (10 females and 6 males) with Class I malocclusion treated
orthodontically with extraction of a mandibular incisor. The mean age at the
beginning of treatment was 23.45 years (SD = 9.14), at the end of treatment was
25.50 years (SD = 8.95) and in the control phase, 30.11 years (SD = 8.59). The
treatment had a mean duration of 2.05 years (S.D. = 0.45) and post treatment
evaluation time was 4.60 years (S.D. = 1.85). It was evaluated the Little irregularity
index and intercanine, interpremolar and intermolar distances in the 3 stages
evaluated. The sample was divided into 2 groups, for comparison of the relapse of
mandibular anterior crowding in cases with or without 3x3 retainer in the control
phase. ANOVA for repeated measures was used to compare intragroup between 3
phases evaluated. The independent t test was used for intergroup comparison.
Results: There was a significant correction of mandibular anterior crowding with
treatment, and a significant relapse after treatment. Cases without 3x3 in the control
phase had a post treatment relapse of mandibular anterior crowding significantly
higher than cases with the 3x3 at the control stage. Conclusion: The cases treated
orthodontic ally with extraction of a mandibular incisor presented a statistically
significant relapse of mandibular anterior crowding after treatment.
