To Evaluate the Correlation Between Skeletal and Dental Parameters to the Amount of Crowding in Class II Div. 1 Malocclusions ZC22-ZC27

摘要

Introduction: Crowding of teeth is one of the most common problem that motivates the patient to seek orthodontic treatment. Determination of etiology of crowding could have a significant effect on treatment planning and prognosis of Class II malocclusion.Aim: Aim of this study was to evaluate the relationship of skeletal and dental parameters to amount of dental crowding in patients with Class II Divison 1 (div.1) malocclusion.Materials and Methods: Pretreatment lateral cephalograms and dental casts of 60 patients with skeletal Class II malocclusion were collected for the study. The sample was divided into two groups according to severity of pretreatment mandibular crowding. Group I consisted of cases with crowding =3 mm and Group II with crowding <3 mm. Lateral cephalograms for each patient was manually traced and skeletal parameters (effective maxillary and mandibular length, mandibular plane angle, Y Axis, lower anterior face height) and dental parameters (axial inclination of lower incisor, inclination of lower incisor to mandibular plane, interincisal angle) were measured. Unpaired t-test was used for intergroup comparison and relationship between different measurements was investigated using Pearson correlation coefficient.Results: Among the skeletal parameters measured, only effective mandibular length exhibited statistically significant difference between the two groups. No statistically significant difference was found between the two groups for any of the dental parameters. Significant inverse correlation was found between mandibular crowding and effective mandibular length.Conclusion: Subjects with Class II div.1 malocclusion and moderate to severe mandibular crowding have significantly smaller effective mandibular base length than subjects with the same malocclusion and slight mandibular crowding.