RESUMO
OBJECTIVE: To evaluate the maxillary alveolar buccal bone levels after expansion with banded and bonded expanders, using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: The population sample consisted of 22 patients who required expansion during their comprehensive treatment; 10 patients (five males and five females) with a mean age of 13.5 years (CVMS 3) had bonded hygienic expanders, and 12 (six males and six females) with a mean age of 12.6 years (CVMS 3) had banded hyrax expanders. CBCT was taken both before (T1) and 6 months after last activation (T2). Measurements were made for buccal bone thickness (BT), buccal marginal bone level (MBL), and bone thickness level (BTL) at the right first molar (M(Rt)), left first molar (M(Lft)), right first premolar (PM(Rt)), and left first premolar (PM(Lft)). A mixed-design analysis of variance assessed differences between and within the groups. Post hoc t-tests were completed on significant analysis of variance results to determine where differences occurred. RESULTS: Analysis of variance revealed no significant differences between or within the two groups. BT significantly decreased horizontally following rapid maxillary expansion. The amount of bone lost was -0.59 mm M(Rt), -0.72 mm PM(Rt), -0.50 mm M(Lft), and -0.57 mm PM(Lft) (P < .003). CONCLUSIONS: There was no significant difference between or within the two groups. Buccal bone loss in the vertical dimension (MBL) only showed significance in the banded group for M(Rt) (0.63 mm) and PM(LFt) (0.37 mm) as evidenced by the paired t-test (P < .05).