Abstract:
PROPOSITION: The objective of this study was to compare changes in maxillary and
mandibular dental arch dimensions in cases treated nonextraction with conventional
appliances and self-ligating Damon System. MATERIAL AND METHODS: initial (T1)
and final (T2) dental casts of 45 patients with Class I malocclusion treated
nonextraction, with slight to moderate crowding, divided into two groups. Group 1: 21
patients treated with self-ligating Damon appliances, at a mean initial age of 18.37
years and mean treatment time of 2.11 years. Group 2: 24 patients treated with
conventional appliances, at a mean initial age of 19.50 years and mean treatment
time of 1.99 years. Measurements in maxillary and mandibular arches were made of
intercanine, interpremolar (first and second premolars) and intermolar distances and
arch length. Intragroup comparison was performed with dependent t or Wilcoxon
tests and intergroup comparison, with independent t or Mann Whitney tests.
RESULTS: In intergroup comparison of treatment changes (T2-T1) the Damon group
presented an increase in maxillary transversal dimensions significantly greater than
the conventional group. The change in maxillary arch length did not show difference
between the groups. Regarding the mandibular arch, the Damon group presented a
significantly greater increase in intercanine and inter first premolars than the
conventional group. In The mandibular arch length, the greater and significant
increase was observed in the groups of patients treated with conventional
appliances. CONCLUSIONS: The treatment with the Damon appliance resulted in a
significantly greater increase of maxillary arch dimensions when compared to
conventional appliance. Mandibular intercanine and interpremolar distances
presented also greater increase in Damon than conventional appliances. The
increase in mandibular arch length was greater in conventional than in Damon group.
