Dental arch dimensions of adolescent Kuwaitis with untreated ideal occlusion: Variation and validity of proposed expansion indexes

Introduction The purposes of this study were to analyze the variations in dental arch dimensions of a large representative sample of adolescent Kuwaitis with untreated almost ideal occlusion and to test the validity of proposed expansion indexes and multivariate linear regression with inclusion of lateral and posteroanterior cephalometric parameters for estimation of dental arch width. Methods Study models and both lateral and posteroanterior cephalograms of 143 Kuwaitis, aged 13 to 14 years, clinically diagnosed with untreated almost ideal occlusion during screening of a population-based sample, were examined. Maxillary and mandibular arch dimensions were measured by using a digital caliper accurate to 0.01 mm, and cephalometric parameters were measured electronically. Results All dimensions were greater in boys than in girls ( P