title: A maximally sensitive clinical decision rule to reduce the need for radiography in mandibular trauma.
abstract: BACKGROUND
  To identify clinical symptoms and signs that exclude the presence of mandibular fracture in patients presenting with mandibular trauma and thus devise a clinical decision rule that will rule out the need for radiography in some patients.
  
  
  METHODS
  A prospective study was conducted of consecutive patients with a possible diagnosis of mandibular fracture who attended a city-centre emergency department between July 2000 and December 2001. Clinical symptoms and signs were recorded for each patient using a predesigned proforma. Radiographic evaluation of a suspected mandibular fracture consisted of lateral-oblique and postero-anterior mandibular views. The presence of a fracture was based on the interpretation of the X-rays by a radiologist who was blinded to the clinical probability of a fracture. Data were initially analysed using the chi-square test. Recursive partitioning was then performed to create a maximally sensitive decision tree.
  
  
  RESULTS
  280 patients were included in the study, 65 of whom had a mandibular fracture. A maximally sensitive decision rule was found that identified 5 parameters (malocclusion, trismus, broken teeth, pain with mouth closed, step deformity) whose absence excluded mandibular fracture. This rule has a sensitivity of 100% and specificity of 39% in identifying patients with mandibular fracture. If applied to our patient cohort, this rule would have saved 83 radiographs without missing any fractures.
  
  
  CONCLUSIONS
  A simple decision rule is presented that can be used to exclude the need for radiography in a subset of patients with mandibular trauma.
authors.affiliation: Department of Emergency Medicine, Manchester Royal Infirmary, Manchester, UK.
authors.forename: C
authors.initials: C
authors.lastname: Charalambous
authors.forename: J
authors.initials: J
authors.lastname: Dunning
authors.forename: S
authors.initials: S
authors.lastname: Omorphos
authors.forename: S
authors.initials: S
authors.lastname: Cleanthous
authors.forename: P
authors.initials: P
authors.lastname: Begum
authors.forename: K
authors.initials: K
authors.lastname: Mackway-Jones
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D003663:Decision Trees; D003937:Diagnosis, Differential; D004630:Emergencies; D005260:Female; D006801:Humans; D008297:Male; D008337:Mandibular Fractures / Q000175:diagnosis* / Q000000981:diagnostic imaging; D008875:Middle Aged; D011446:Prospective Studies; D011859:Radiography; D012680:Sensitivity and Specificity; D016037:Single-Blind Method