Interrelationship between the position of impacted maxillary canines and the morphology of the maxilla

Introduction: The aim of this study was to examine whether there is a relationship between the position of impacted maxillary canines and the morphology of the maxilla. Methods: The palatally impacted canine group included 18 boys and 27 girls with an average age of 12 years 9 months (+/-2 years 1 month). The buccally impacted canine group comprised 19 boys and 26 girls with an average age of 12 years 2 months (+/-1 year 4 months). Arch length/intermolar width x 100 was used as the value for comparison of maxillary arch shapes, and palatal vault depth/intermolar width x 100 was used to compare the shapes of palate between the 2 groups. Each category was directly measured from the diagnostic model. Results: Both the arch length/intermolar width x 100 and the palatal vault depth/intermolar width x 100 formulas showed statistically significant differences (P < 0.0001), indicating differences in the shape of maxillary arch and the palatal vault between the 2 groups. Conclusions: The shape of the maxillary arch was narrower and longer in the palatally impacted canine group compared with the buccally impacted canine group, and the palatally impacted canine group had a deeper palatal vault than did the buccally impacted canine group. (Am J Orthod Dentofacial Orthop 2012;141:556-62)