Position And Characteristics Study Of Maxillary Impacted Canines In Cone-beam Computed Tomography And Panoramic Tomograph

Objective:To find panoramic tomographic closely related predictors of maxillary impact canines by the analysis of the mesial and distal position of crown,the mesial and distal position of root,the inclination of the dental axis and the teeth length of the maxillary impacted canines on panoramic tomographs,comparing the position of maxillary impact canines on cone-beam computed tomographys(CBCT).Methods : Collected the general datas of 141 patients who had unilateral impacted maxillary canines from the Orthodontics Department of the Stomatology Hospital affiliated to China Medical University from 2006 to 2018.A total of 141 maxillary impacted canines and 141 contralateral non-impacted canines were used as study group and control group respectively.(1)The NNT Viewer software and Planmeca Dimaxis Pro software were used to measure and analyze the cone-beam computed tomographys and panoramic tomographs respectively.The mesial and distal position of the maxillary impacted canine in the panoramic tomographs was divided into 5 sector(?~? sector),and the position of labiopalatal side was determined by CBCT.(2)The difference between the mesial and distal position distribution of crown and root,the inclination of the dental axis and the teeth length of the teeth of the study group and the control group was measured and analyzed in the panoramic tomographs.Results :(1)The labiopalatal distribution of the maxillary impacted canines was significantly different between sexes(?2 = 12.684,P = 0.002),the maxillary impacted canines in female patients are more common in the labial side than in the male patients in the palatal side.A statistically significant association was observed between the labiopalatal positions in the cone-beam computed tomographys and the mesial and distal position of root in panoramic tomographs of the impacted canines(r = 0.232,P =0.006),but the mesial and distal position of crown(r = 0.004,P = 0.964).(2)There are differences in the distribution of the mesial and distal positions of the crown and root between the two groups(?2 = 221.316,64.689 respectively;both P < 0.001).In the study group,the axis of the maxillary impacted canine was more inclined and the length of the teeth was shorter than that in the control group(t = 15.895,-3.712 respectively;both P < 0.05).Conclusion:Different distribution of labiopalatal position of maxillary impacted canines in different genders.The labiopalatal position can be implicated by the location of the mesial and distal position of the maxillary impacted canine root in the panoramic tomographs.The mesial and distal position of root,the inclination of the dental axis and the tooth length can be closely related predictors of maxillary impacted canines.