A Study of the Quality of Finish of Lingual versus Labial Bracket Systems As Measured By the Objective Grading System: A Retrospective Study in a University Orthodontic Clinic

Objective: The purposes of this study were to determine the quality of final orthodontic treatment outcome and average treatment time with fixed lingual brackets compared to labial brackets. Our hypothesis was that labial fixed appliances produce a higher quality of final treatment outcome, and a shorter average treatment time compared to lingual fixed appliances. Materials and Methods: This was a retrospective study of matched pairs. Records of twenty subjects treated with lingual appliances were included. These were paired with twenty patient records of subjects in fixed labial appliances with matching initial discrepancy index (DI) (±5 points), Angle classification (within one-half step), number of extracted teeth, and age. Final models were scored using the eight criteria of the American Board of Orthodontics’ Objective Grading System (OGS) and treatment time was recorded in number of days. Results: The mean difference in OGS scores between groups was 2.00 ± 8.89 points with a mean OGS score of the labial and lingual fixed appliance groups of 21.6 ± 7.45 and 19.6 ± 6.43, respectively. This difference was not statistically significant (p = 0.33). Lingual subjects’ treatment time was an average of 4.25 ± 213.78 days less compared to their matched labial subjects. This difference was not significant (p = 0.93). A statistically significant difference was found in the buccolingual inclination subcategory of the OGS. The mean difference in the buccolingual inclination score of lingual subjects was 1.90 ± 3.52 points higher than labial subjects (p = 0.03). Conclusion: Lingual fixed appliance subjects had no significant difference in treatment time and / or treatment outcome as measured by OGS when paired with labial fixed appliance subjects, however, they did have significantly higher buccolingual inclination discrepancies.