Abstract:
The aim of this retrospective study was to evaluate the dental arch dimensional
changes (intercanine, intermolar and arch width) of Class I of Angle patients treated with
and without extraction of first premolars. Sixty-one orthodontic patients, ranging from
(11,5 to 28 years-old) were selected for this study and distributed into 2 groups: (A) No
extraction nd (B) extraction of first premolars. Pre- and post-treatment die casts were
used for the dimensional measurements. The intercanine and intermolar distances and
arch width measurements were measured using a digital caliper. To evaluate the nonextraction
and extraction treatment comparison within each group independent t-tests
were used (p=0.05). There was significant difference in the intercanine distance only
before orthodontic treatment. There were intermolar dimensional changes between
extraction and non-extraction treatments after orthodontic treatment for both groups.
When comparing posttreatment arch dimensions, there was a decrease in the
mandibular arch width in the extraction group. First premolars extraction may alter arch
dimensions and orthodontic treatment outcome and must be indicated carefully
according to patient individual needs.
