title: Relationship between lower wisdom tooth position and cyst development, deep abscess formation and mandibular angle fracture.
abstract: OBJECTIVE
  There is an ongoing controversy about indications for prophylactic removal of third molars. The purpose of this retrospective study was to clarify the risk of preservation of lower third molars.
  
  
  METHODS
  In a 5-year period, 316 patients were registered who had received in-patient treatment for deep abscess formation, cyst formation or mandibular angle fracture in relation to lower third molars. A radiological analysis (panoramic radiographs) was performed to determine whether major pathological changes associated with lower wisdom teeth are related to their position. Third molar positions were studied in this in-patient group and in an out-patient group. The latter consisted of 300 consecutive patients with prophylactically removed impacted third molars without any pathology. The relationship between the positions and the different pathological changes associated with impacted lower wisdom teeth was analysed statistically using a new 'position score'.
  
  
  RESULTS
  The study revealed that the highest 'position scores' corresponding to a leading aberrant position correlated significantly with cyst formation. Lower scores corresponding to moderately aberrant or slightly irregular position were found with angle fractures, abscess formation, and in the control group as a whole.
  
  
  CONCLUSIONS
  This study indicates that prophylactic third molar surgery for teeth with high and strongly elevated 'position scores' is appropriate in order to prevent cyst formation or mandibular angle fractures in a population at risk for facial trauma. In addition to other factors, 'position score' data could be useful for development of a model for predicting severe complications related to (removal of) impacted lower wisdom teeth.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Central German Armed Forces Hospital, Koblenz, Germany. Rwerkmeister@bundeswehr.org
authors.forename: Richard
authors.initials: R
authors.lastname: Werkmeister
authors.forename: Thomas
authors.initials: T
authors.lastname: Fillies
authors.forename: Ulrich
authors.initials: U
authors.lastname: Joos
authors.forename: Koord
authors.initials: K
authors.lastname: Smolka
mesh_terms: D000038:Abscess / Q000209:etiology* / Q000517:prevention & control; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D002648:Child; D003362:Cost-Benefit Analysis; D005260:Female; D006801:Humans; D007570:Jaw Cysts / Q000209:etiology* / Q000517:prevention & control; D008297:Male; D008335:Mandibular Condyle / Q000000981:diagnostic imaging / Q000293:injuries; D008336:Mandibular Diseases / Q000000981:diagnostic imaging / Q000209:etiology* / Q000517:prevention & control; D008337:Mandibular Fractures / Q000000981:diagnostic imaging / Q000209:etiology*; D008875:Middle Aged; D008964:Molar, Third / Q000000981:diagnostic imaging / Q000601:surgery; D011859:Radiography; D012189:Retrospective Studies; D012307:Risk Factors; D018709:Statistics, Nonparametric; D014081:Tooth Extraction / Q000191:economics; D014095:Tooth, Impacted / Q000150:complications / Q000000981:diagnostic imaging; D014097:Tooth, Unerupted / Q000150:complications / Q000000981:diagnostic imaging