Comparison of treatment outcomes as assessed by 3 indexes in subjects with class I malocclusion treated by 3 different methods: A cross-sectional study

Document Type



Dental-oral, Maxillo-facial Surgery


Introduction: Various treatment modalities exist to improve and correct Class I malocclusion. This study was conducted to evaluate the outcomes of nonextraction (NE), premolar extraction (PME), and mandibular incisor extraction (MIE) treatment modalities in subjects presenting with Class I malocclusion.
Methods: A cross-sectional study was conducted at a tertiary care hospital using pretreatment and posttreatment dental casts along with intraoral photographs of 90 orthodontic subjects. These subjects were divided equally into NE, PME, and MIE groups and scored using the Index of Orthodontic Treatment Need, Index of Complexity, Outcome, and Need (ICON), and peer assessment rating (PAR) indexes. Nonparametric tests were run to compare pretreatment and posttreatment scores and to evaluate the percentage and categorical changes for the treatment modalities. Pairwise comparisons were performed using the Mann-Whitney U test.
Results: Statistically significant differences (P ≤0.001) were seen between the pretreatment and posttreatment scores for all modalities. Statistically significant improvements were seen between the 3 treatment modalities for the PAR (P = 0.010) and ICON (P = 0.003) indexes. Significant categorical improvements were found for the Aesthetic Component (AC) (P = 0.012) among the 3 groups. Pairwise comparison revealed significant differences between the NE and MIE groups (ICON, P = 0.001; AC, P = 0.018) and PME and MIE groups (PAR, P = 0.002; ICON, P = 0.007; AC, P = 0.007).
Conclusions: Posttreatment scores of all indexes were reduced, with significant differences found among the treatment modalities for all except the Dental Health Component index. The pairwise comparison revealed suboptimal occlusal results with the MIE group. Good occlusal and esthetic treatment outcomes were achieved with the PME and NE groups.


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Publication (Name of Journal)

American Journal of Orthodontics and Dentofacial Orthopedics