Traumatic Lesions of Face



Traumatic Lesions of Face


Michelle A. Michel, MD



DIFFERENTIAL DIAGNOSIS


Common



  • Fracture, Nasal Bone


  • Fracture, Mandible


  • Fracture, Zygomaticomaxillary Complex


  • Fracture, Inferior Orbital


  • Fracture, Medial Orbital Blowout


Less Common



  • Fracture, Nasoethmoid Complex


  • Fracture, Frontal Sinus


  • Fracture, Transfacial (Le Fort)


Rare but Important



  • Fracture, Complex Midfacial


  • Trauma/Dislocation, TMJ


ESSENTIAL INFORMATION


Key Differential Diagnosis Issues



  • 75% of facial fractures (fx) occur in mandible, zygoma, & nose


  • Mechanisms: Auto accidents > assaults > falls > sports injuries



    • Penetrating trauma less common fx cause


  • Force required to fx facial bones classified as high or low impact



    • High impact fxs: Supraorbital rim, mandibular symphysis, fronto-glabellar, mandibular angle



      • Incidence of other major injuries ≈ 50%


    • Low impact fxs: Zygoma, nasal bones


  • Imaging recommendations



    • High-resolution MDCT is modality of choice for rapid evaluation of facial trauma


    • 3D images helpful for surgical planning


    • Plain films used in focal trauma (nasal fx)


Helpful Clues for Common Diagnoses



  • Fracture, Nasal Bone



    • Most common facial fx



      • Less force required to fracture nasal bone compared to other bones


    • Most are diagnosed clinically



      • Imaging obtained to plan repair if deformity persists after edema resolves


    • Imaging: Evaluate for associated septal hematoma requiring evacuation


  • Fracture, Mandible



    • Frequently multiple ± bilateral on opposite sides of symphysis



      • Essentially “ring of bone” with “fixation” at TMJs


    • Degree of fx displacement depends on fx orientation & muscle attachments


    • Locations: Condylar > coronoid process > ramus > angle > body > parasymphyseal > symphyseal > alveolar process


    • Associated imaging: TMJ dislocation (condylar/subcondylar fx)



      • Hypesthesia over chin with fx through alveolar foramen (parasymphyseal)


      • 15% have at least 1 other facial bone fx


  • Fracture, Zygomaticomaxillary Complex



    • Zygoma is exposed facial bone



      • Fx results from forceful blow to cheek


      • Central depression with fx at both ends


      • Isolated zygoma fx is rare


    • Trismus results from impingement on temporalis muscle



      • Lateral orbital fx fragments may impinge lateral rectus


    • Imaging: “Tripod” or “tetrapod” fx involves separation of 3 major attachments of zygoma from face



      • Fx of maxillary sinus & lateral orbital wall (diastasis of zygomaticofrontal suture) in addition to zygoma


      • Look for involvement of orbital apex/optic canal


  • Fracture, Inferior Orbital



    • “Blowout” term used with floor fx & intact infraorbital rim


    • Orbital muscle entrapment is clinical diagnosis


    • Typically results from blunt trauma



      • Infraorbital rim & orbital floor are thin; most common sites of orbital fracture


      • May be associated with zygomaticomaxillary complex fx


      • Look for associated lamina papyracea fx (medial orbital blowout)


    • Imaging: Suspect orbital floor fracture if hemorrhage or “trapdoor” or “fallen fragment” noted on axial head CT



      • Other findings: Pneumo-orbita, ocular injury (24%); chronic enophthalmos


  • Fracture, Medial Orbital Blowout



    • Results from blunt trauma


    • Imaging: Medial displacement of lamina papyracea




      • Herniation of extraconal fat ± medial rectus muscle into defect


      • Orbital floor fracture may be associated


Helpful Clues for Less Common Diagnoses



  • Fracture, Nasoethmoid Complex



    • Results from trauma to nasal bridge



      • Fx extends into nose through ethmoids


    • Widening of nasal bridge on physical examination


    • More serious than isolated nasal bone fx


    • Imaging: Fx of nasal bone & ethmoid sinuses ± cribriform plate



      • Cribriform plate fx ⇒ CSF rhinorrhea


  • Fracture, Frontal Sinus



    • Anterior wall fx with depression ⇒ cosmetic deformity & hypesthesia in distribution of supraorbital nerve


    • Posterior wall fx ⇒ CSF leak, meningitis, or parenchymal brain injury


  • Fracture, Transfacial (Le Fort)



    • Complex, bilateral fx with large unstable fragment (“floating face”)



      • Invariably involves pterygoid plates


    • Pure Le Fort fx rarely seen & may vary from side-to-side


    • Facial distortion (elongated face), mobile maxilla, malocclusion, or midface instability may be present clinically


    • Le Fort I: Transverse fx of maxilla above maxillary teeth



      • Involves medial & lateral maxillary sinus walls, septum, pterygoid plates


      • Most common Le Fort type


      • Mobile hard palate on physical exam


    • Le Fort II: Pyramid fx of maxilla



      • Apex above nasal bridge with inferolateral extension through infraorbital rims


      • Mobile maxilla & subconjunctival hemorrhages on physical exam


    • Le Fort III: Craniofacial disruption



      • Requires significant causative force


      • Fx involves maxilla, zygoma, lateral orbital walls


      • Mobility of all facial bones relative to cranium on physical exam

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Aug 8, 2016 | Posted by in OTOLARYNGOLOGY | Comments Off on Traumatic Lesions of Face

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