Abstract
Aims: The aim of this study was to investigate if there is a correlation between the shape of the crowns of the incisors and crowding. Materials and Methods: Plaster models of 100 individuals having class I molar relationship were chosen .By using the irregularity index, 51 individuals (22 males and 29 fe-males) were considered to be the crowding group(irregularity index >3mm),and 49 individuals (23 males and 26 females) were considered to be the normal group(irregularity index< 3mm).The casts were selected from the POP department at the college of dentistry in Mosul University. Repeated mea-surements of the maximum mesiodistal width of the incisal and cervical areas of the incisors were tak-en by means of a vernier caliper and a ratios of these measurements were calculated. Results:The mean value for the crowding group was significantly higher in the incisal area of lower incisors and upper central incisors than corresponding values in the normal group. A significant correlation was present between upper irregularity index and upper lateral incisor mesiodistal width ratio. Conclusions: The lower incisors were more triangulary shaped in the crowding group than those in the normal one.
