Comparison of the mesiodistal angulation of maxillary canines based on their impaction sector in panoramic radiographs: A cross-sectional study.

INTRODUCTION: The complexity of treating impacted maxillary canines varies based on their angulation and position within the dental arch. The aim of this research was to compare the mesiodistal angulation of maxillary canines according to their impaction sector. METHODS: This cross-sectional study evaluated 229 impacted maxillary canines in 171 panoramic radiographs from two private radiology centres in Uruguay and Chile of individuals of both sexes aged 11 years and older with impacted maxillary canines. The radiographs were taken with two panoramic radiography equipment. All the images were evaluated using Planmeca Romexis(R) software. Two investigators were trained and calibrated to perform all the measurements at two measurement times. The Ericson and Kurol method was used to classify the impaction sector into five sectors and the Wardorf method was used to measure the mesiodistal impaction angle and, finally, the level of impaction was measured with respect to the root of the lateral incisor. Student t-test, Anova and multiple linear regression were used. P<0.05. RESULTS: The impaction angle of sectors 1 and 2 was (70.03 degrees +/-9.65 degrees ) and of sectors 3, 4 and 5 it was 52.21 degrees +/-16.60 degrees (P<0.001) while at the cervical level of the lateral incisor root it was 74.15 degrees , 68.04 degrees at mid-level and 57.39 degrees at the apical level (P<0.001). The impaction angle decreases 13.02 degrees in sectors 3, 4 and 5 (P<0.001), for each year the impaction angle decreases 0.30 degrees (P=0.001), and as the level of impaction becomes more apical the impaction angle decreases 7.46 degrees . CONCLUSIONS: Impacted maxillary canines are more horizontal the closer they are to the midline or the higher the level of impaction. Likewise, this horizontality tends to increase over time. All these considerations should be taken into account by orthodontists when planning their treatments.