title: The effects of impacted premaxillary supernumerary teeth on permanent incisors.
abstract: OBJECTIVE
  The aim of this study was to examine the radiographic features associated with impacted premaxillary supernumerary teeth, to determine the relationship between their characteristics and their effects on permanent incisors, and to investigate the types of orthodontic treatment that patients received after the extraction of impacted supernumerary teeth.
  
  
  METHODS
  The clinical records and radiographs of 193 patients whose impacted premaxillary supernumerary teeth were removed were retrospectively reviewed, and 241 impacted supernumerary teeth were examined. Cone-beam computed tomographic images and panoramic radiographs were examined to determine the number, location, sagittal position, orientation, and morphology of the supernumerary teeth. Their effects on permanent incisors and the orthodontic treatment received by patients after the extraction of the supernumeraries were also investigated.
  
  
  RESULTS
  Supernumerary teeth were most frequently observed in the central incisor region, in the palatal position, in the inverted orientation, and were most commonly conical in shape. The most common complication was median diastema, followed by displacement and delayed eruption of the adjacent incisors. Ten (71.4%) of the 14 odontomas showed delayed eruption of the adjacent incisors. Displacement of the incisors was more frequently observed in association with supernumerary teeth with tuberculate or supplemental shapes. Orthodontic traction was most frequently performed after the removal of odontomas. In 32 cases (13.3%), permanent incisors erupted after the orthodontic creation of sufficient space.
  
  
  CONCLUSIONS
  Median diastema was most common complication. The delayed eruption of incisors was common in supernumerary teeth with a vertical orientation and an odontoma shape.
authors.affiliation: Department of Oral and Maxillofacial Radiology, School of Dentistry, Pusan National University, Yangsan, Korea.
authors.forename: Yun-Hoa
authors.initials: YH
authors.lastname: Jung
authors.affiliation: Department of Pediatric Dentistry, School of Dentistry, Pusan National University, Yangsan, Korea.
authors.forename: Ji-Yeon
authors.initials: JY
authors.lastname: Kim
authors.affiliation: Department of Oral and Maxillofacial Radiology, School of Dentistry, Pusan National University, Yangsan, Korea.
authors.forename: Bong-Hae
authors.initials: BH
authors.lastname: Cho
keywords: Cone-Beam Computed Tomography; Maxilla; Tooth, Supernumerary