In orthodontic treatment, indication of dental extractions is very common and frequently used in adult patients. This situation is a recurrent concern among orthodontists, since age and extraction treatment are factors that may increase periodontal support loss. Therefore, this study aimed to evaluate adolescent and adult patients, orthodontically treated with maxillary premolar extractions, and compare both groups regarding the changes in alveolar bone height loss, retrospectively.

Fifty-five patients were selected from the files of an Orthodontic Department and divided into 2 groups. The adolescent group comprised 30 patients with a mean age of 12.7 years (SD=1.4) and the adult group comprised 25 patients with a mean age of 25.0 years (SD=1.8). Periapical radiographs obtained at pre-treatment (T1) and posttreatment (T2) were evaluated. Wilcoxon tests were used to analyse intragroup treatment changes. Mann-Whitney tests were used to compare intergroup and inter-sex initial and final statuses and treatment changes. P<0.05 is considered to be statistically significant.

Statistically significant increases in alveolar bone height loss of the maxillary central incisors were observed on the right and left sides of the adolescent (P=0.001 and P=0.002, respectively) and of the adult (P=0.001 and P<0.001, respectively) groups, during treatment. There were no significant differences in alveolar bone height between initial and final state, in treatment effects between adolescent and adult patients, in extraction patterns, and between males and females.

Significant increase in alveolar bone height loss was found in both adult and adolescent patients orthodontically treated with maxillary premolar extractions. However, no significant differences were found regarding alveolar bone height changes after extraction orthodontic treatment between adolescent and adult patients.