title: Relationship between the risk of mandibular angle fractures and the status of incompletely erupted mandibular third molars.
abstract: BACKGROUND
  Several studies have shown the increased risk of mandibular angle fractures associated with incompletely erupted mandibular third molars. But only a few reports analysed in detail the relationship of the status of eruption of this tooth and this type of fracture.
  
  
  OBJECTIVE
  The purpose of this study was to clarify the influence of the eruption status of incompletely erupted mandibular third molars on the incidence of mandibular angle fractures.
  
  
  METHODS
  Four hundred and thirty-six mandibular halves in 218 patients with mandibular fractures, aged between 15 and 40 years old, were analysed using panoramic radiographs.
  
  
  RESULTS
  The incidence of angle fractures in the mandibular halves with incompletely erupted mandibular third molars was 30.8% and this was statistically significantly higher than that in another group (p<0.0001). Deeply located mandibular third molars clearly showed a higher incidence of this fracture when compared with the adjacent second molar (p<0.0001).
  
  
  CONCLUSIONS
  The results of this investigation showed that incompletely erupted mandibular third molars close to the inferior border of the mandible have a high risk of angle fractures.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Ruprecht Karls University of Heidelberg, Heidelberg, Germany. iida@dent.osaka-u.ac.jp
authors.forename: Seiji
authors.initials: S
authors.lastname: Iida
authors.forename: Stefan
authors.initials: S
authors.lastname: Hassfeld
authors.forename: Tobias
authors.initials: T
authors.lastname: Reuther
authors.forename: Kimiko
authors.initials: K
authors.lastname: Nomura
authors.forename: Joachim
authors.initials: J
authors.lastname: Mühling
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008335:Mandibular Condyle / Q000000981:diagnostic imaging / Q000293:injuries; D008337:Mandibular Fractures / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000209:etiology*; D008964:Molar, Third / Q000000981:diagnostic imaging; D011859:Radiography; D012307:Risk Factors; D014097:Tooth, Unerupted / Q000150:complications* / Q000000981:diagnostic imaging