Association between maxillary canine impaction and arch dimensions

To compare palatal height index, arch width, and arch length characteristics in Iranian patients presenting with palatal and buccal canine impaction with a matched control group.

The casecontrol study examined 53 patients with canine impaction. The subjects were divided into two groups determined by buccal or palatal impaction which were compared with 53 control subjects presenting without impaction. Subjects in the experimental groups were matched with individuals in the control group according to age, gender, crowding and type of malocclusion. Palatal height and arch length were measured with a Korkhaus three-dimensional divider. Arch width was determined in the anterior and posterior portions of the maxillary arch with a digital caliper. Data were compared with paired t-tests.

The buccal canine impaction group exhibited mean differences in arch length between the case and control groups of 0.8 mm (SD 1.63, p = 0.041). The differences between the case and control groups in intermolar width, interpremolar width, intercanine width, palatal depth, and palatal height index were not statistically significant. The palatal impaction group showed no statistically significant differences between the case and control group in any of the dependent variables (p < or = 0.05). In a retest examination of arch dimensions, Bland-Altman plots showed no differences between the first and second measurements.

Arch length in the buccal canine group was the only statistically significant variable. The difference was small and was considered not clinically significant.