Relationship between pre-treatment orthodontic case complexities and their treatment outcomes

Abstract

Purpose

To determine whether pre-treatment orthodontic case complexities were associated with their treatment outcomes in each category of malocclusion.

Materials and methods

Two hundred orthodontic cases treated with edgewise appliances from university clinic that satisfied requirements for the certification were studied. The Discrepancy Index (DI) and the Objective Grading System (OGS) were calculated. The relationship between these measurements was evaluated using Pearson’s correlation coefficient.

Results

The mean DI score was 23.67 ± 10.30, and the mean OGS score was 19.92 ± 6.92. Statistically, there was only a weak and insignificant correlation between the DI and OGS (r = 0.055, p > 0.05). Buccolingual inclinations and interproximal contacts were components that had the highest and lowest mean OGS scores respectively.

Conclusion

Malocclusion complexity was not associated with orthodontic treatment outcomes. Cases which underwent two-phase treatment were found to have the most complex pre-treatment malocclusion and also the most unsatisfactory clinical outcomes. The OGS component with the highest discrepancies was buccolingual inclinations.

Keywords:

• Discrepancy index
• Objective grading system
• Orthodontic pre-treatment case complexity
• Orthodontic treatment outcomes

Acknowledgement

We are deeply indebted to Mahidol University, Thailand for this research support.