RESUMO
Background: Arch dimensions such as arch width, arch lengthand arch form are very significant to orthodontic treatment.Diagnosis of arch length and width discrepancies are importantdiagnostic aids, with the help of which treatment outcome canbe predicted. The present study was conducted to evaluate thearch width among class I normal occlusion, Class II division 1and Class III malocclusions.Materials and Methods: In the present study a total of 75pairs of study models were selected to evaluate the arch widthamong class I normal occlusion, Class II division 1and Class IIImalocclusion. For the evaluation of arch width pretreatmentorthodontic study models were selected from orthodonticrecords. Each malocclusion class consisted of 25 studymodels. Measurements were performed on the orthodonticstudy models using an electronic digital caliper measuring tothe nearest 0.01 mm. One operator measured the arch widthparameters on both jaws. Statistical analysis was performedusing the Statistical Package for the Social Sciences softwareversion 21.0 (SPSS Inc., Chicago, IL, USA). A p-value <0.05was predetermined as statistically significant.Results: In the present study each malocclusion classconsisted of 25 study models of participants seekingorthodontic treatment. Class III and Class I groups showedsignificantly larger maxillary intercanine widths, larger maxillaryintermolar, inter premolar and alveolar widths than Class IIdivision1 groups. In mandible Class III group showedsignificantly larger mandibular intercanine, inter rmolar thanClass I and Class II division 1 groups. Class I shows largerinter-premolar width and inter alveolar width than Class III andClass II division 1 groups.Conclusion: Our study concluded that arch widh dimensionsvary according to malocclusion and hence measurement ofarch width provides important information for diagnosis andtreatment planning.