Carrea's index in dental students at the Federal University of Paraíba

Aim: To determine the applicability of Carrea's index in arches with normal tooth position and diastema and to evaluate its use in the maxillary arch.
Methods: 51 pairs of plaster models made by dental students from the Federal University of Paraíba were analyzed. The arches and hemiarches were divided according to dental position and measured with a manual caliper and a digital caliper. With these measurements, maximum and minimum heights were estimated, comparing the values to the real height of the subjects. The data were then submitted to Pearson's chi-square test and Fischer's Exact test (CI = 95%).
Results: In the mandibular hemiarches, there was statistically significant difference (p=0.017) between the types of dental position only in women, with crowded teeth obtaining the highest number of hits (95.2%), followed by diastema (50.0%). Only the left hemiarch was significantly different (p=0.049) and crowded teeth had the highest index of hits (82.6%), whereas diastema accounted for 40.0%. In the maxillary arch, the error percentage was 100% in the three types of dental position.
Conclusion: Carrea's index is applicable in normal and crowded teeth. However, it was not efficient in the maxillary arch and in hemiarches with diastema.