Associations between pretreatment age and treatment time with orthodontic treatment outcome: A comparison by means of two orthodontic indices.

AIM: To compare the associations between pretreatment age and treatment time with orthodontic treatment outcome by means of two orthodontic indices.DESIGN: A retrospective analysis of treated patients.SETTING: The study was conducted at the accredited graduate Orthodontic Clinic of the University of Illinois at Chicago (UIC), USA.MATERIALS AND METHODS: The study casts of 100 treated orthodontic cases were randomly selected from the model store of the clinic without bias for age, gender or race.MAIN OUTCOME MEASURES: The pretreatment study casts and their corresponding post treatment casts were assessed using the original Peer Assessment Rating (PAR) Index while the same post treatment study casts were also assessed using the American Board of Orthodontics Objective Grading System (ABO OGS), by a calibrated examiner. All the ABO OGS criteria were assessed except the radiographic component (root angulations). The associations were examined using chi-square tests.RESULTS: Using the PAR Index, statistically significant associations were found between orthodontic treatment outcomes and pre-treatment age (p = 0.010) as well as between orthodontic treatment outcome and treatment time (p = 0.035). No statistically significant associations were found between orthodontic treatment outcomes and pre-treatment age (p = 0.926) or treatment time (p = 0.900), according to the ABO OGS.CONCLUSION: Despite the general good finishes of the studied cases, the PAR Index was sensitive to the pretreatment age and treatment duration in assessing the quality of orthodontic treatment outcome unlike the ABO OGS.