How to read Facial Bone Xrays (45 mins)

Dr Peter Andre Soltau3rd year A&E ResidentUWI MonaP.A.SOLTAU@GMAIL.com

Epidemiology

Incidence :20 -50% of cases admitted to traumatic emergency room

Etiology:1) M.V.A (up to 80%)2) Direct Force e.g Fights (up to 60%)3) Falls (up to 25%)4) Sports (up to 10%)5) Industrial accidents

Facial Fractures

Soft tissue injury is more common

Co-existence of other injuries: 3 - 14% have skull fractures 1 - 4% have c-spine fractures 20% of patients with c-spince

fractures have facial injury

Facial Fractures

Most common is nasal bone fracture

Site vary based on mechanism on injury

In admitted patients, most common fracture is of the ZMC (40%) followed by complex fractures

Less common in children <10% (mid-face less prominent, sinuses less pneumatized, elasticy of bones)

Imaging

Why: Identify fractures, fracture displacement and rotation,

stable bone Identify soft tissue injury

CT is the modality of choice !!! high accuracy (soft tissue and bone detail) cost saving versus multiple view plain radiography easier quicker pre-op planning

ImagingPlain Film Radiography

can be obtained if CT not available must have proper patient positioning of the head alignment of x-ray beam is critical multiple projections obtained relative to "canthomeateal line"

(outer canthus to EA meatus overlapping obscures anatomic detail if a fracture is identified other than a simple nasal bone fracture -

CT is required

AnatomyFamiliarity with facial bone anatomy is required for accurate interpretation

Face is defined as that area which is bounded by

superiorly - supra-orbital rims inferiorly - maxillary alveolar process

Plain X-rays Views

Water's View (P.A view with cephalad angulation)Caldwell View (P.A view)Towne ViewLateral ViewSubmentovertex / Basal

Additional view: lateral nasal bone view

Adult Facial Bones - PA Caldwell

Adult Facial Bones - Occipito Mental (OM) (Waters) View

Adult Facial Bones - PA 30° (Modified Parietocanthial)

Adult Facial Bones - Occipito Mental 30° (OM30) View

Adult Facial Bones - Lateral View

Adult Facial Bones - Submentovertex (SMV) / Slit Basal / Jughandles View

Adult Facial Bones - Slit Townes

Pearls

Rule of symmetry : symmetry is usual, asymmetry is suspectFacial fractures usu occur in multiples

Radiographic signs of facial fractures

Direct Signsnonanatomic linear lucenciescortical defect or diastatic suturebone fragments overlapping causing a "double-density"asymmetry of face

Indirect Signssoft tissue swellingperiorbital or intracranial airfluid in a paranasal sinus

Dolan LinesThree anatomic contours best seen on the Waters view of the face, and they were first popularized by Dolan et al. As you can see, the 3 lines of Dolan lead the eye along some facially important structures. Lee Rogers pointed out that the 2nd and 3rd lines together form the profile of an elephant.

Line 1:Look for widening of the zygomatico-frontal suturesFractures of the superior rim of the orbits“Black-Eyebrow” sign due to orbital emphysemaOpacification / air-fluid level in the frontal sinusesLine 2:Look for fractures of the superior aspect of the zygomatic archFractures of the inferior rim of the orbitsSoft tissue shadow in the superior maxillary antrumFractures of the nasoethmoid bones and medial orbitsLine 3:Look for fractures of the inferior aspect of the zygomatic archFractures of the lateral maxillary antrumOpacification / air-fluid level in the maxillary sinusesFractures of the alveolar ridgeCompare the injured side with the uninjured side.

McGrigor-Campbell interpretation lines Facial bone fractures result from direct trauma and usually follow one of only a small number of patterns. 'McGrigor-Campbell' lines can be used as a simple aid to interpretation. The eye follows these lines to check for these common fracture patterns.

Facial fracturesMost common facial fractures:

Nasal bone fracture Isolated zygomatic arch fracture Tripod or zygomaticomaxillary complex fracture( involves

separation of all three major attachments of the zygoma to the rest of the face)

Orbital "blowout" fractures

Fracture TypePrevalence:Zygomaticomaxillary complex (tripod fracture) - 40 %LeFort

I - 15 % II - 10 % III - 10 %

Zygomatic arch - 10 %Alveolar process of maxilla - 5 %Smash fractures - 5 %Other - 5 %

Isolated zygomatic arch fracture

'Tripod' fractures

Maxillary antrum fluid level

Orbital 'blowout' fracturesTrauma to the orbit may lead to increased pressure in the orbit such that the thin bone of the orbital floor bursts. This manifests as the 'teardrop' sign which is due to herniation of orbital contents into the maxillary antrum.

Orbital 'blowout' fracture- Teardrop sign

Orbital emphysema

Occasionally a 'tripod' or 'blowout' fracture will cause a leak of air from the maxillary antrum into the orbit. This can have the appearance of a dark 'eyebrow'.

Fractures of the Maxilla

The classification of maxilla fractures again follows the concept of areas of relative strength within the facial skeleton There are three principal fracture lines which correspond to relative areas of weakness, and these are referred to as LeFort fractures

By definition, these fractures must transect the pterygoid process of the sphenoid bone.

LeFort I

This is a transverse fracture through the inferior maxillary antra, which separates off the alveolar process of the maxilla. The LeFort I is demonstrated on the OM view with fractures through the medial and lateral walls of the maxillary antra, and the nasal septum

LeFort IIThis is a pyramidal fracture, which separates off the central portion of the face. The OM film identifies the LeFort II with fractures through the lacrimal bones, medial orbital walls, infra-orbital rim and lateral walls of the maxillary antra.

LeFort IIIThis fracture is characterised by separation of the entire facial skeleton from the skull. The posterior aspect of the fracture extends down the posterior maxillary sinus walls. Fracture lines will be visible on the OM view extending from the medial orbits and nasoethmoid region across the ethmoids posteriorly. The orbits appear elongated with wide diastasis of the zygomatico-frontal sutures, or fractures of the orbital process of the zygoma.

Pathology Spotters

Pathology Spotters

Pathology Spotters

Pathology Spotters

SummaryAnalysis of the fractured face requires a knowledge of not only normal anatomy, but also of common fracture patterns in the faceThe workup and treatment of facial fractures is often properly delayed until more pressing problems have been addressed, such as the establishment of an adequate airway, hemodynamic stabilization, and the evaluation and treatment of other more serious injuriesKnow the most common patterns of facial fractures and look for themSymmetry is frequent, asymmetry is suspect

SummaryPlain film is a 2D representation of a 3D objectAlways utilise a systematic approachCorrelate radiological findings with clinical features

References1.http://www.wikiradiography.net/page/Facial+Bones+Radiographic+Anatomy2.http://radiologymasterclass.co.uk/tutorials/musculoskeletal/x-ray_trauma_spinal/x-ray_face_fracture.html#top_first_img3.http://www.rad.washington.edu/academics/academic-sections/msk/teaching-materials/online-musculoskeletal-radiology-book/facial-and-mandibular-fracture4.http://www.imageinterpretation.co.uk/face.html

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