title: The risk of healing complications in primary teeth with extrusive or lateral luxation-A retrospective cohort study.
abstract: OBJECTIVE
  Traumatic dental injuries (TDI) in the primary dentition occur frequently. Long-term complications may potentially cause damage to the permanent successor. The aim of this study was to report the risk of pulp necrosis (PN), pulp canal obliteration (PCO), infection-related resorption (IRR), ankylosis-related resorption (ARR) and premature tooth loss (PTL) in primary teeth following extrusion or lateral luxation and to identify risk factors for PN and PTL.
  
  
  METHODS
  This was a retrospective study of 24 patients with 26 extruded primary teeth and 242 patients with 331 primary teeth with lateral luxation. Laterally luxated teeth were left without treatment. Extruded teeth were repositioned. Follow up included examination after 4 weeks, 8 weeks, 6 months, 1 year and when the patients were 6 years old. The minimum follow up was 1 year or until tooth loss. Kaplan-Meier and Aahlen-Johansson tests were used along with Cox regression analysis. The level of significance was 5%.
  
  
  RESULTS
  Risk estimated after 3 years-Extrusion: PCO 39.8% (95% CI: NA), PN 15.6% (95% CI: 1.5-29.7), IRR 3.8% (95% CI: 0-11.2) and PTL 43.3% (95% CI: 25.5-61.2). All cases of PN and PTL occurred within the first year. Lateral luxation: PCO 41.3% (CI: 95% 35.7-46.9), PN 19.8% CI: 95% (15.3-24.2), IRR 7.0% (95% CI: 4.1-9.8), ARR 1.4% (95% CI: 0-3.3) and PTL 24.8% (95% CI: 18.8-30.8). Risk factors for PN: concomitant crown fracture and patient aged 4 years or more. Nearly all teeth (95%) realigned spontaneously within the first year. Nearly all cases of PN and PTL (95.7%) occurred within the first year.
  
  
  CONCLUSIONS
  The healing potential for laterally luxated teeth was high and more than half of the extruded teeth, which were repositioned after injury, showed long-term survival.
authors.affiliation: Resource Centre for Rare Oral Diseases, Department of Oral and Maxillo-Facial Surgery, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.
authors.forename: Eva
authors.identifier: http://orcid.org/0000-0003-0859-7262
authors.initials: E
authors.lastname: Lauridsen
authors.affiliation: Department of Public Health, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Paul
authors.initials: P
authors.lastname: Blanche
authors.affiliation: School of Oral health Care, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Nadia
authors.initials: N
authors.lastname: Yousaf
authors.affiliation: Resource Centre for Rare Oral Diseases, Department of Oral and Maxillo-Facial Surgery, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.
authors.forename: Jens O
authors.initials: JO
authors.lastname: Andreasen
mesh_terms: D002648:Child; D003718:Denmark; D003790:Dental Pulp Necrosis / Q000209:etiology*; D005260:Female; D006801:Humans; D008297:Male; D012189:Retrospective Studies; D012307:Risk Factors; D012391:Root Resorption / Q000209:etiology*; D014084:Tooth Avulsion / Q000150:complications*; D016388:Tooth Loss / Q000209:etiology*; D014094:Tooth, Deciduous; D014945:Wound Healing
keywords: Dental trauma; extrusion; lateral luxation; primary teeth; pulp necrosis; root resorption