title: A novel classification of frontal bone fractures: The prognostic significance of vertical fracture trajectory and skull base extension.
abstract: OBJECTIVE
  The broad spectrum of frontal bone fractures, including those with orbital and skull base extension, is poorly understood. We propose a novel classification scheme for frontal bone fractures.
  
  
  METHODS
  Maxillofacial CT scans of trauma patients were reviewed over a five year period, and frontal bone fractures were classified: Type 1: Frontal sinus fracture without vertical extension. Type 2: Vertical fracture through the orbit without frontal sinus involvement. Type 3: Vertical fracture through the frontal sinus without orbit involvement. Type 4: Vertical fracture through the frontal sinus and ipsilateral orbit. Type 5: Vertical fracture through the frontal sinus and contralateral or bilateral orbits. We also identified the depth of skull base extension, and performed a chart review to identify associated complications.
  
  
  RESULTS
  149 frontal bone fractures, including 51 non-vertical frontal sinus (Type 1, 34.2%) and 98 vertical (Types 2-5, 65.8%) fractures were identified. Vertical fractures penetrated the middle or posterior cranial fossa significantly more often than non-vertical fractures (62.2 v. 15.7%, p = 0.0001) and had a significantly higher mortality rate (18.4 v. 0%, p < 0.05). Vertical fractures with frontal sinus and orbital extension, and fractures that penetrated the middle or posterior cranial fossa had the strongest association with intracranial injuries, optic neuropathy, disability, and death (p < 0.05).
  
  
  CONCLUSIONS
  Vertical frontal bone fractures carry a worse prognosis than frontal bone fractures without a vertical pattern. In addition, vertical fractures with extension into the frontal sinus and orbit, or with extension into the middle or posterior cranial fossa have the highest complication rate and mortality.
authors.affiliation: Division of Plastic and Reconstructive Surgery, Department of Surgery, University of Wisconsin, Madison, WI, USA.
authors.forename: Ravi K
authors.initials: RK
authors.lastname: Garg
authors.affiliation: Division of Plastic and Reconstructive Surgery, Department of Surgery, University of Wisconsin, Madison, WI, USA; Division of Plastic Surgery, Cairo University, Cairo, Egypt. Electronic address: afifi@surgery.wisc.edu.
authors.forename: Ahmed M
authors.initials: AM
authors.lastname: Afifi
authors.affiliation: Division of Plastic and Reconstructive Surgery, Department of Surgery, University of Wisconsin, Madison, WI, USA.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Gassner
authors.affiliation: Section of Head and Neck Imaging, Department of Radiology, University of Wisconsin, Madison, WI, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Hartman
authors.affiliation: Department of Surgery, University of Wisconsin, Madison, WI, USA.
authors.forename: Glen
authors.initials: G
authors.lastname: Leverson
authors.affiliation: Division of Plastic and Reconstructive Surgery, Department of Surgery, University of Wisconsin, Madison, WI, USA.
authors.forename: Timothy W
authors.initials: TW
authors.lastname: King
authors.affiliation: Division of Plastic and Reconstructive Surgery, Department of Surgery, University of Wisconsin, Madison, WI, USA.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Bentz
authors.affiliation: Section of Head and Neck Imaging, Department of Radiology, University of Wisconsin, Madison, WI, USA.
authors.forename: Lindell R
authors.initials: LR
authors.lastname: Gentry
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D001930:Brain Injuries / Q000175:diagnosis / Q000453:epidemiology; D015984:Causality; D002648:Child; D002675:Child, Preschool; D015897:Comorbidity; D018450:Disease Progression; D005151:Facial Injuries; D005260:Female; D050723:Fractures, Bone / Q000145:classification*; D005624:Frontal Bone / Q000000981:diagnostic imaging / Q000293:injuries*; D005626:Frontal Sinus / Q000293:injuries; D023261:Glasgow Outcome Scale; D006801:Humans; D007223:Infant; D038801:International Classification of Diseases; D008297:Male; D008875:Middle Aged; D009104:Multiple Trauma / Q000145:classification* / Q000000981:diagnostic imaging* / Q000453:epidemiology; D009901:Optic Nerve Diseases / Q000453:epidemiology; D009915:Orbit / Q000293:injuries; D011379:Prognosis; D012189:Retrospective Studies; D019291:Skull Base / Q000293:injuries*; D012887:Skull Fractures / Q000000981:diagnostic imaging* / Q000453:epidemiology; D020521:Stroke / Q000453:epidemiology; D013345:Subarachnoid Hemorrhage / Q000453:epidemiology; D015996:Survival Rate; D014057:Tomography, X-Ray Computed; D055815:Young Adult
keywords: Craniomaxillofacial trauma; Frontal bone fracture; Frontal sinus fracture; Orbital fracture; Skull base trauma