Palatally Impacted Canines- Analysis of Cementum

Objectives: Palatal canine ectopia is frequently seen in patients referred for orthodontic treatment. There is considerable evidence to support the view that genetic factors are the primary origin of such displacement, and Runx2 has been proposed as a candidate gene. Mutation of Runx2 in patients with cleidocranial dysplasia causes delayed and ectopic eruption of permanent teeth and also cementum abnormalities. The aim of this study was to evaluate any differences in the distribution of cementum on the roots of palatally displaced canines, extracted from non-syndromic patients, compared to canines which erupted normally.

Methods: A sample of 12 extracted canines, which had been palatally displaced, was compared to an age-matched control group of 5 canines. Sections were prepared from cervical, middle and apical root thirds, perpendicular to the long axis of each tooth. Cementum area was calculated using image analysis software.

Results: Median cementum area of the cervical root sections was greater in the impacted canine group (3.535 mm2) than the control group (3.03 mm2). The middle root thirds also showed increased cementum area in the ectopic group (4.14 mm2) compared to controls (3.94 mm2). The apical root section measurements showed a reduced cementum area in the impacted canine group (8.44 mm2) compared to the control canines (10.5 mm2). However, differences in the median values were not sufficient to exclude the possibility that these variations were due to random sampling variability. Conclusion: The results indicated that there was no statistically significant difference between the cementum distribution on palatally impacted canines and maxillary canines which erupted normally (p>0.05).