1 Faculty of Dentistry, Department of Orthodontics, Shahid Sadoughi University of Medical Sciences, Yazd, IR Iran

2 Faculty of Dentistry, Department of Orthodontics, Kashan University of Medical Sciences, Kashan, IR Iran


Background: The aim of this study was to verify the prevalence of three different morphologies of the mandibular and maxillary dental arch in natural normal occlusions and that may help guiding orthodontists customizing shape of orthodontic archwires. The orthodontist should know the mean of inter-canine and inter-molar width of Iranian population to help as a guide of treatment.
Methods: We examined 132 study models including 66 maxillary and 66 mandibular arches. Three square, ovoid, and tapered templates were overlaid on arches using special software. Samples were categorized according to the adaptability of templates on images. Inter canine and inter molar widths were also measured on casts and recorded.
Results: Ovoid was the most frequent form (54%) in Iranian population. Tapered (36%) and square (10%) forms were on second and third steps, respectively. The relative frequencies of tapered and ovoid forms were equal in the mandibular arch while in the maxillary arch, the frequency of ovoid (63%) was significantly higher than tapered (27%).
Conclusions: Ovoid is the most common dental arch form in Iranian population.