title: Scandinavian multicenter study on the treatment of 168 patients with 230 intruded permanent teeth - a retrospective cohort study.
abstract: OBJECTIVE
  The aim of the study was to evaluate the survival of intruded permanent teeth related to treatment in a large number of patients, with special focus on development of pulp necrosis and replacement resorption (ankylosis-related resorption).
  
  
  METHODS
  The material consisted of 168 patients (mean age 9.6 years) with 230 intruded permanent teeth from dental trauma clinics in Copenhagen, Denmark, Stockholm, Sweden, and Oslo, Norway. The degree of intrusion was classified as mild (1-<3 mm), moderate (3-7 mm), and severe (>7 mm). Root development was categorized with respect to root formation and development of the apex into three groups of increasing tooth maturity: very immature, immature, and mature.
  
  
  RESULTS
  Awaiting re-eruption was the treatment of choice in 107 teeth (47%), orthodontic repositioning in 28 (12%) and surgical repositioning in 95 (41%) teeth. Pulp necrosis was diagnosed in 173 teeth (75%), infection-related root resorption in 57 (25%) and replacement resorption in 50 teeth (22%). Very immature teeth, teeth diagnosed with mild intrusion, and teeth awaiting re-eruption had significantly (P < 0.05) fewer complications. In a stepwise discriminant function analysis, choice of treatment, root development, and degree of intrusion were significantly (P < 0.05) associated with the development of replacement resorption. Root development and degree of intrusion were significantly (P < 0.05) associated with the development of pulp necrosis.
  
  
  CONCLUSIONS
  This study indicates that root development and degree of intrusion may be important for the development of pulp necrosis as well as replacement resorption, whereas choice of treatment only seems to influence the development of replacement resorption in intruded permanent teeth. Awaiting re-eruption resulted in the lowest risk for developing replacement resorption.
authors.affiliation: Department of Dental Medicine, Division of Pediatric Dentistry, Karolinska Institutet, Stockholm, Sweden. georgios.tsilingaridis@ki.se.|Department of Pediatric Dentistry, Eastmaninstitutet, Stockholm, Sweden. georgios.tsilingaridis@ki.se.
authors.forename: Georgios
authors.initials: G
authors.lastname: Tsilingaridis
authors.affiliation: Department of Dental Medicine, Division of Pediatric Dentistry, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Barbro
authors.initials: B
authors.lastname: Malmgren
authors.affiliation: Department of Oral and Maxillofacial Surgery, Resource Centre for Rare Oral Diseases, University Hospital, Copenhagen, Denmark.
authors.forename: Jens O
authors.initials: JO
authors.lastname: Andreasen
authors.affiliation: Department of Pediatric Dentistry and Behavioral Science, Institute of Clinical Dentistry, University of Oslo, Oslo, Norway.
authors.forename: Tove I
authors.initials: TI
authors.lastname: Wigen
authors.affiliation: Department of Pediatric Dentistry and Behavioral Science, Institute of Clinical Dentistry, University of Oslo, Oslo, Norway.
authors.forename: Anne-Lise
authors.initials: AL
authors.lastname: Maseng Aas
authors.affiliation: Orthodontic Clinic, Huddinge, Sweden.
authors.forename: Olle
authors.initials: O
authors.lastname: Malmgren
mesh_terms: D002648:Child; D003718:Denmark; D003790:Dental Pulp Necrosis; D005260:Female; D006801:Humans; D008297:Male; D009664:Norway; D012189:Retrospective Studies; D012391:Root Resorption; D013548:Sweden; D014084:Tooth Avulsion / Q000628:therapy*
keywords: dental trauma; intrusion; permanent teeth; pulp necrosis; replacement resorption; treatment