Evaluation of The Dental Arch Width in a Group of Orthodontic Class I and II Yemeni Children

Abstract

The dental arch dimensions (width, length, and depth) have a significant effect in orthodontic diagnosis, treatment planning and treatment outcomes. The aim of this study was to evaluate of the dental arch width in a group of orthodontic class I and II Yemeni children. The study included 100 Yemeni children in the early mixed dentition who were divided based on Angel’s classification and occlusal features into two groups:50 child (28 males and 22 females mean age 9.9 ± 1.07) with Angel class I and normal occlusion (class I group), and 50 child (34males and 16 females mean age 9.88± 1.06) with Angel class II and class II division 1 malocclusion( class II group). The class II group was subsequently divided into two subgroups (maxillary protrusion group and mandibular retrusion group) based on skeletal characteristics taken from lateral cephalometric radiographs. Intermolar and intercanine distance were measured in both arches using Mitutoyo digital caliper, and posterior transvers interarch deficiency (PTID) and anterior transvers interarch deficiency (ATID) were calculated. Statistical analysis was conducted using sample t-test for class I and class II comparison, and for comparison between the class II subgroups. Finding of this study showed that patients with class II malocclusion have a significantly greater negative PTID ( -1.69mm) which was and associated with significantly reduced maxillary intermolar width when compared to class I patients( - 1.07mm). The class II patients showed also a significantly reduced ATID(0.55mm) when compared to class I patients(1.15mm). There were no significant differences in any of the arch width measurements between class II mandibular retrusion and class II maxillary protrusion patients. In conclusion, patients with class II division 1 malocclusion have a significant constriction of the maxillary arch with reduced intermolar width and with greater negative PTID and a more reduced ATID compared to class I patients.