Influence of the maxillary dimensions and lateral incisor anatomy on the palatal impaction of maxillary permanent canines: A three-dimensional case-control study

Objective > The diagnosis of impacted upper permanent canines (IUPC) is a relatively common clinical finding. The aim of this study was to investigate associations between the upper permanent canines palatal impaction, lateral incisors morphology and the maxilla bone base.Material and methods > Cone-beam tomography files from 62 subjects were divided into 2 groups: impaction group (ICG/n = 31; mean age 14.3 +/- 2.4) with 45 canines impacted on the palatal side and age-and sex-matched control group (CG/n = 31; mean age 14.3 +/- 2.3), with 62 normally erupted canines. Linear and volumetric measurements of the lateral incisors, linear transversal measures and the maxillary anterior perimeter were taken. Independent Student's t-test was used for intergroup analysis with correction of Bonferroni.Results > Significant differences were found for crown length and root diameter (buccal-palatal) (P < 0.005). The maxillary anterior perimeter in the ICG was reduced in relation to the GC but not significantly (P = 0.008). The transverse skeletal variables of the maxilla were equivalent in the intergroup comparison (P > 0.005).Conclusion > Smaller dimensions in the crown length and in the upper permanent lateral incisors root buccal-palatal diameter were associated with the impaction of upper permanent canines on the palatal side. The maxillary transverse morphology did not show any association with the occurrence of this condition.