Early Radiographic Features of Maxillary Canine Impaction for Orthodontically Diagnosed Children Aged Between 8-14 Years Old

摘要

The early detection and diagnosis of maxillary canine impaction affect the planning of its treatment. Certain radiographic features may be used in order to diagnose such impaction.Aim: To study the radiographic features for detection of the maxillary canine impaction in children and the changes associated with these features over time.Materials and Methods: This was a retrospective cross-sectional study that included 37 children aged between 8-14-years-old. Each patient must be diagnosed orthodontically with canine impaction by the failure of its eruption clinically and by using Panoramic Radiographs (PRs). The patient must have at least two PR with at least a one-year interval (T1 and T2) between them both. The following radiographic features have been used to identify maxillary canine impaction: 1) the vertical canine crown height; 2) the degree of canine overlap in relation to any adjacent teeth; 3) the magnitude of canine to lateral incisor angle and 4) the magnitude of the canine to midline angle measurement. The null hypothesis for this study was that there is no difference in the radiographic features between impacted and non-impacted canines in children overtime.Results: An assessment of the panoramic radiographs that were obtained at a later stage (T2) was carried out, which revealed that 56.76% of the canines were impacted whilst 43.24% had erupted normally. Impacted canines showed a significantly higher vertical crown height in relation to the adjacent teeth at T1 (p=0.01). Around 60% of the non-impacted canines were located in a normal position apical to the primary canine. However, the crown of impacted canine was around 75% placed either distal or mesial to the permanent lateral incisor (p<0.001). The mean values for both the canine-lateral incisor angle and the canine to midline angle were increased significantly (p<0.01) in the impacted canines. The canine to midline angle was decreased significantly (p=0.02) by an average of 5° over time in the non-impacted cases, whereas it did not change in the case of impacted canines.Conclusion: The radiographic features can help to identify canine impaction at an early stage if it is: 1) located at a higher vertical position than the adjacent teeth; 2) overlapped with the lateral incisor 3) a canine-lateral incisor angle of more than 30° is present; and 4) the canine angulation in relation to the midline is more than 54.1°.