Mohammad Esmaeilzadeh
Sanaz Afzalsoltani

Background: Permanent tooth impaction is a relatively common abnormality in which early treatment can prevent from other developmental disorders. Maxillary central impaction can occur because of mesiodens, dilacerations, trauma to deciduous tooth and space deficiency. Prevalence of maxillary central impaction is ۰.۰۶%-۲.۰%. Methods: In this retrospective, case-control study, ۲۸ people with impacted maxillary central incisor and ۵۶ as the control group were studied. All participants were ۸-۱۲ years old. The data were collected from private offices of orthodontists and special pediatric dentists and Hamadan dental school. The data required were diagnostic models, initial panoramic radiography and initial lateral cephalometry radiography. Data analysis was done by SPSS software using t test and chi-square test. ۳\ Results: The most common causes of maxillary central impaction were: mesiodens (۷۴.۴%), dilacerations (۱۴.۳%), space deficiency (۱۰.۷%) and cyst (۳.۶%). ۸۹.۳% of cases had unilateral maxillary central impaction and ۱۰.۷% had bilateral maxillary central impaction. There was a significant relation between skeletal class II and maxillary central impaction. ANB angle was significantly higher in impaction group than in control group (P<۰.۰۵). In most of the patients with maxillary central impaction, ipsilateral canines had upper position compared with the contralateral side (۶۰%). Conclusions: Presence of mesiodens was the most important reason for maxillary central incisor impaction, and class II jaw relation is more common in patients with maxillary central incisor impaction, which higher incidence of vertical disorders can be a bigger challenge in these patients.