Objective: To evaluate and compare the relationship between the Collum angle of maxillary central incisors and root resorption following non extraction orthodontic treatment.
Materials and Methods: A total of 80 patients (age range 1325 years) were divided into two groups based on malocclusion type and Collum angle. The relationship between Collum angle and root resorption was assessed using the Chi-square test.
Results: Group I (Class I) subjects showed a mean Collum angle of ?7.4º pre-treatment and ?5.5º post-treatment, while Group II (Class II Division 2) had a significantly higher angle of 8.2º pre-treatment and 5.9º post-treatment. Pre-treatment root resorption was milder in both groups, with Group II showing predominantly Grade 0 resorption. Post-treatment, root resorption severity increased in both groups, but was more pronounced in Group II, with 25% showing Grade 3 resorption. Overall, 99% of patients exhibited some degree of resorption, with statistically significant differences between groups both before (p = 0.003) and after (p = 0.013) treatment, indicating that higher Collum angles in Class II Division 2 malocclusions are associated with greater root resorption following orthodontic therapy.
Conclusions: The Collum Angle of maxillary central incisors in Class II Division 2 malocclusions was greater than Class I malocclusions and is associated with increased root resorption following orthodontic treatment.
Keywords: Collum angle, Orthodontically induced root resorption, Class I and Class II Division 2 malocclusion, Anterior teeth biomechanics, Orthodontic treatment.
