Abstract:
The aim of this study was to compare the cephalometric changes between
treatment with extraction of four first premolars and four first molars. It was a
retrospective study of a group treated with extraction of 4 first premolars (G1) and
another with extraction of 4 first molars (G2). Group 1 comprised 25 patients (8
males and 17 females) with initial mean age of 14.61 years (SD = 2.65). Group 2
comprised 11 patients (1 male and 10 female) with an initial mean age of 21.57
years (SD = 6.71). The comparison between groups was made from lateral
cephalograms in the initial and final cephalometric tracings in all subjects.
Cephalometric variables were organized into components for better data
distribution. Statistical analysis of differences in the same group was made by
dependent t test. For intergroup comparison, it was applied independent t tests,
where variables were compared to initial (T1), the changes with treatment
between the groups (T2-T1), and differences between the groups at the end of
treatment (T2). The results showed that, with treatment, there was a greater
increase in maxillary effective length in G2, when compared to G1. Changes were
similar in G1 and G2 for the mandibular component, maxillomandibular relationship
and tegumental profile during treatment. There was a counterclockwise rotation of
the occlusal plane in G1 and in clockwise rotation in G2. The maxillary incisors were
more retracted, uprighted and extruded and maxillary molars were more moved
mesially inG2 in relation to G1. Mandibular incisors were significantly more uprighted
in G1 and second mandibular molars were more moved mesially in G2. The overbite
was decreased in G1 and increased in G2, and there was more correction of the
molar relationship in G1, in relation to G2.
