RESUMEN
<p><b>OBJECTIVE</b>To investigate the frequency, sex differences and location of impacted maxillary canine in orthodontic patients.</p><p><b>METHODS</b>Two hundred and fifteen patients (77 males and 138 females) with maxillary canine impaction were included in the study. The experimental group was gathered from the Department of Orthodontics, Peking University School and Hospital of Stomatology. CT scan images were evaluated. Chi-square test was used in the analysis.</p><p><b>RESULTS</b>The prevalence of maxillary canine impaction among Chinese orthodontic patients was 2.05%. The ratio between male and female was 1.8:1 and the ratio between buccal and palatal location was 2.1:1. Surgical exposure and orthodontic alignment had been predominant in such conditions. There was significant deference in the treatment between palatally impacted canine and buccally impacted one. More palatally impacted canines were extracted than buccally impacted ones.</p><p><b>CONCLUSIONS</b>There was significant difference in the treatment of maxillary canine impaction. More buccally impacted canines were found in Chinese patients, especially in female patients.</p>