Alveolar base and dental arch widths with segmental arch measurements in different classes of malocclusions : a comparative study

Abstract EN

Background : The size and shape of the arches have considerable implications in orthodontic diagnosis and treatment planning.

The aim was to evaluate and compare alveolar bases, dental arches and segmental arch dimensions of class II division 1, class III malocclusion groups with normal occlusion subjects and to check gender differences and maxillary and mandibular arch widths difference.

Materials and Methods : Dental casts of 62 subjects aged between 18 - 28 years were included in the study.

They were equally divided between males and females, consisting of 26 class I normal, 22 Class II division 1, and 14 Class III malocclusion and eleven liner measurements were utilized for each dental arch.

Results : All measured dimensions were greater in males than in females except for mandibular inter alveolar premolar width and maxillary left canine molar distance in class III malocclusion and in maxilla than in mandible except inter molar width in class II and class III groups and alveolar base dimensions in class III malocclusion.

In class I all measurements were wider than class II division 1 while, in class III was wider than class I in all mandibular alveolar base and mandibular inter premolar width and wider in all maxillary dental arch widths, all mandibular alveolar base dimensions and mandibular inter canine and premolar widths than class II division 1 group.

Conclusion : Maxillary molar teeth in subjects with Class II division1 tend to incline buccally to compensate the insufficient alveolar base, while subjects with Class III malocclusion maxillary posterior teeth tend to incline lingually and mandibular posterior teeth inclined buccally due to the restriction in maxillary arch.