Aim: The etiology of teeth impaction is still not fully understood, despite that cofactors have been considered important to develop such a clinical picture. The aim of the authors' paper was to investigate about facial biotype, about the values of inclination of the upper cuspid axis to the perpendicular to Frankfort-horizontal plane and about the distance "d" of the canine cuspid to occlusal plane: each factor was statistically compared. The authors also performed a comparative analysis on the radicular length of the left and right lateral incisors of subjects with impacted maxillary canine.
Methods: The authors recruited with "cluster sampling" randomization more than 30 patients, then refined to 25 after the application of exclusion criteria. Specific values were carried out by x-rays: the authors calculated both the α and β angles, the intermaxillary angle, the distance "d" and the inclination of upper cuspid axis to the perpendicular-to-Frankfort-horizontal plane. Spearman rank correlation coefficient or Spearman rho (ρ) was used as statistical methods.
Results: The authors' results assessed that the inclination of the upper cuspid axis to the perpendicular-to-Frankfort-horizontal plane showed a statistically significant inverse correlation with the intermaxillary angle.
Conclusion: The authors' data clearly indicate that hyperdivergence is a key-factor that will certainly support the eruption path of canine cuspid: in this light, the treatment of tooth impaction in hyperdivergent subjects can be considered as predictive for a good prognosis.