3. Themes  Key landmarks Clinically relevant “Gotcha” injuries ○ Easy-to-miss, land you in trouble  Simplify approaches to classification, where possible  Differentiating one fracture pattern from another

5. Of Processes and Terminology

6. Temporal Bone Frontal Bone Maxillary Bone

7. Of Processes and Terminology Temporal Bone Frontal Bone Maxillary Bone Frontal process of zygomatic bone

8. Of Processes and Terminology Temporal Bone Frontal Bone Maxillary Bone Zygomatic process of frontal bone

9. Of Processes and Terminology Temporal Bone Frontal Bone Maxillary Bone Maxillary process of zygomatic bone

10. Of Processes and Terminology Temporal Bone Frontal Bone Maxillary Bone Zygomatic process of maxillary bone

12. Clinical Relevance of Fracture Diagnosis  Fracture repair timing Ideally <6-12h ○ Before onset of edema ○ Usually infeasible due to other injuries 3-7d post-injury ○ Edema begins to settle  Early fixation (<10d) reduces errors from scar and callus  Timely diagnosis is critical  CT is critical because underlying deformity may be obscured by edema * Diagram and photo credits: www2.aofoundation.org and shenbagamhospital.org

13. Classification of Facial Fractures  Solitary Strut Isolated frontal or maxillary sinus wall Isolated zygomatic arch Nasal arch Isolated orbital floor, or medial wall or rim  Complex Strut Naso-orbitoethmoidal, nasomaxillary Zygomaticomaxillary complex  Transfacial LeFort I, II, III  Mandibular * Modified from Kassell EE, Gruss JS: Neuroimaging Clin N Am 1:259, 1991

15. Frontal Sinus Fractures  Direct blow to supraorbital region  High force injury (>800 lbs)  Anterior wall Forms the frontal bar Contributes to facial projection Foundation for vertical buttresses  Posterior wall Separates sinus from cranial vault Projection

16. Frontal Sinus Fractures  Key landmark: nasofrontal duct  Duct dysfunction may lead to mucocele formation  Frontal sinus obliterated prophylactically Mucosa stripped and sinus packed with bone or fat Coronal CT: Frontal Mucocele 36M Facial injury ten years ago Coronal CT: Normal Example 59F Normal Normal Duct

17. Nasal Bone Fracture 61M Pedestrian struck Axial CT: Simple Nasal Bone Fracture  Common 50% of all facial fractures  Watch for: Septal hematoma ○ Saddle nose deformity Anterior nasal spine fracture ○ Chronic pain Involvement of medial orbital wall

18. Nasal Bone Fracture  Common 50% of all facial fractures  Watch for: Septal hematoma ○ Saddle nose deformity Anterior nasal spine fracture ○ Chronic pain Involvement of medial orbital wall Axial CT: Paraseptal Hematoma * Photo credit: http://images.rheumatology.org Saddle Nose* 22M Blunt trauma to face

19. Nasal Bone Fracture  Common 50% of all facial fractures  Watch for: Septal hematoma ○ Saddle nose deformity Anterior nasal spine fracture ○ Chronic pain Involvement of medial orbital wall 3D SSD: Anterior Nasal Spine 31M Punch to face Lateral View: Anterior Spine Fracture 31M Drunk, fell

20. Nasal Bone Fracture  Common 50% of all facial fractures  Watch for: Septal hematoma ○ Saddle nose deformity Anterior nasal spine fracture ○ Chronic pain Involvement of medial orbital wall Axial CT: Naso-Orbital Ethmoidal Fracture 66M Gunshot wound

23. NOE Fractures  Fractures involve: Nasal bones Frontal process of maxilla Medial canthal region Ethmoid sinus and walls  Strongly associated with: Cribiform plate injury Intracranial injury Dural tears Globe injury Nasal bone Maxilla Lacrimal bone Orbital plate of ethmoid

24. NOE Fracture 61M Pedestrian struck Fractured medial wall Associated open frontal sinus fracture Associated orbital roof blowout Fractured nasal bones

25. NOE Fractures  Key landmark: lacrimal fossa  Medial canthal tendon inserts around fossa Formerly “ligament” Complex structure intimately related to orbicularis oculi  Fracture may cause: Telecanthus Globe malposition  Look for nasolacrimal duct to find the lacrimal fossa

26. NOE Fractures  Key landmark: lacrimal fossa  Medial canthal tendon inserts around fossa  Fracture may cause: Telecanthus Globe malposition  Look for nasolacrimal duct to find the lacrimal fossa * Photo credit: Pham et al. “Computer Modeling and Intraoperative Navigation in Maxillofacial Surgery”. Otolaryngology 137(4): 624-631.

27. NOE Fractures  Key landmark: lacrimal fossa  Medial canthal tendon inserts around fossa  Fracture may cause: Telecanthus Globe malposition  Look for nasolacrimal duct to find the lacrimal fossa 59F Normal study Coronal CT: Normal Nasolacrimal Duct Coronal CT: Normal Lacrimal Fossa

28. NOE Fracture Classification  Markowitz-Manson Classification: Type I ○ Fractured piece is large ○ Medial canthal tendon intact ○ Fixation of bony fragment restores canthal anatomy Type II ○ Comminution ○ Canthus tendon is attached to a small bone fragment Type III ○ Comminution with avulsion of medial canthal tendon ○ Cannot reliably differentiate from Type II on imaging * Hopper et al. Diagnosis of Midface Fractures with CT: What the Surgeon Needs to Know. Radiographics. 2006 May-Jun;26(3):783-93

29. NOE Fracture Classification 38M Fell off bike onto face 3D SSD: Manson Type IAxial: Fractured Nasal Bones & Medial Walls Coronal CT: Fractured Medial Wall and Floor Nasolacrimal Duct Lacrimal Fossa

30. NOE Fracture Classification * Hopper et al. Diagnosis of Midface Fractures with CT: What the Surgeon Needs to Know. Radiographics. 2006 May-Jun;26(3):783-93  Markowitz-Manson Classification: Type I ○ Fractured piece is large ○ Medial canthal tendon intact ○ Fixation of bony fragment restores canthal anatomy Type II ○ Comminution ○ Canthus tendon is attached to a small bone fragment Type III ○ Comminution with avulsion of medial canthal tendon ○ Cannot reliably differentiate from Type II on imaging 3D SSD: Manson Type II 63F Massive blunt force trauma

31. NOE Fracture Classification * Hopper et al. Diagnosis of Midface Fractures with CT: What the Surgeon Needs to Know. Radiographics. 2006 May-Jun;26(3):783-93  Markowitz-Manson Classification: Type I ○ Fractured piece is large ○ Medial canthal tendon intact ○ Fixation of bony fragment restores canthal anatomy Type II ○ Comminution ○ Canthus tendon is attached to a small bone fragment Type III ○ Comminution with avulsion of medial canthal tendon ○ Cannot reliably differentiate from Type II on imaging 3D SSD: Manson Type III 53M Gunshot wound

32. NOE Fracture Classification * Hopper et al. Diagnosis of Midface Fractures with CT: What the Surgeon Needs to Know. Radiographics. 2006 May-Jun;26(3):783-93 Always comment on: The degree of comminution Bilateral involvement Nasofrontal ducts likely disrupted Risk of mucocele formation Frontal sinuses are surgically obliterated

34. Zygoma  “Cornerstone” bone Attachments to frontal, temporal, sphenoid bones of skull base Forms large portions of the orbital floor and lateral orbital wall Attachment to maxilla Contributes to projection, width & height  Accurate diagnosis and reduction is crucial for: Restoring orbital volume Restoring facial projection, height, width Serving as reference for maxilla in Le Fort-type injuries

35. Zygoma Fractures  “Tripod” fractures Region of zygomaticofrontal suture Region of zygomaticotemporal suture Region of zygomaticomaxillary suture  “Tetrapod” fractures Zygomaticosphenoid suture Often involves lateral maxillary wall  Often the zygoma itself is intact Weaker bones and suture lines fracture around zygoma 24M Assaulted 3D SSD

36. Zygoma Fractures  “Tripod” fractures Region of zygomaticofrontal suture Region of zygomaticotemporal suture Region of zygomaticomaxillary suture  “Tetrapod” fractures Zygomaticosphenoid suture Often involves lateral maxillary wall  Often the zygoma itself is intact Weaker bones and suture lines fracture around zygoma

37. “Tetrapod” 42M Punch to face SSD: Fourth Attachment DisruptedSSD: Three of Four Attachments Disrupted

38. Zygoma Fractures  “Tripod” fractures Region of zygomaticofrontal suture Region of zygomaticotemporal suture Region of zygomaticomaxillary suture  “Tetrapod” fractures Zygomaticosphenoid suture Often involves lateral maxillary wall  Often the zygoma itself is intact Weaker bones and suture lines fracture around zygoma 25M Car tire blew up in face 3D SSD: Comminuted Zygomatic Body

39. Zygoma Fractures Preferred Term: Zygomaticomaxillary complex fracture Spectrum of zygomatic Injuries : Isolated zygomatic arch TripodTetrapod Comminution of zygoma Amount of Force

40. ZMC Fracture  Rotation around the zygomaticosphenoid suture is possible even if the upper transverse and lateral vertical maxillary buttresses are fixed  Implications: Report suture disruption Review carefully on follow up imaging Transaxial CT: Zygomaticosphenoid Suture Disruption

42. Le Fort Fractures  Complex, multi-strut  Dissociation of face from skull base at anchor points  Universally involve: Nasal apparatus Pterygoid processes  Classic Le Fort injuries are uncommon  Oversimplification but useful to communicate and to conceptualize injury * Picture credit: Rosario Van Tulpe under GNU Free Documentation License v1.2 1 2 3

43. Simplified Approach Fractured StructureSignificance Pterygoid processLe Fort almost always present Lateral margin of nasal fossaUnique to Le Fort I Inferior orbital rimUnique to Le Fort II Zygomatic archUnique to Le Fort III * Rhea and Novelline. How to Simplify the CT Diagnosis of Le Fort Fractures. AJR Am J Roentgenol. 2005 May; 184(5):1700-5

44. Simplified Approach Fractured StructureSignificance Pterygoid processLe Fort almost always present Lateral margin of nasal fossaUnique to Le Fort I Inferior orbital rimUnique to Le Fort II Zygomatic archUnique to Le Fort III * Rhea and Novelline. How to Simplify the CT Diagnosis of Le Fort Fractures. AJR Am J Roentgenol. 2005 May; 184(5):1700-5 63M Fall Coronal CT: Pterygoid Plate FracturesTransaxial CT: Pterygoid Plate Fractures Fractured StructureSignificance Pterygoid processLe Fort almost always present Lateral margin of nasal fossaUnique to Le Fort I Inferior orbital rimUnique to Le Fort II Zygomatic archUnique to Le Fort III

45. Simplified Approach Fractured StructureSignificance Pterygoid processLe Fort almost always present Lateral margin of nasal fossaUnique to Le Fort I Inferior orbital rimUnique to Le Fort II Zygomatic archUnique to Le Fort III * Rhea and Novelline. How to Simplify the CT Diagnosis of Le Fort Fractures. AJR Am J Roentgenol. 2005 May; 184(5):1700-5 Coronal CT: Pterygoid Plate FractureCoronal CT: Nasal Fossa FractureSSD: Le Fort I

46. Simplified Approach Fractured StructureSignificance Pterygoid processLe Fort almost always present Lateral margin of nasal fossaUnique to Le Fort I Inferior orbital rimUnique to Le Fort II Zygomatic archUnique to Le Fort III * Rhea and Novelline. How to Simplify the CT Diagnosis of Le Fort Fractures. AJR Am J Roentgenol. 2005 May; 184(5):1700-5 Coronal CT: Pterygoid Plate FracturesCoronal CT: Inferior Orbital Rim Fracture

47. Simplified Approach Fractured StructureSignificance Pterygoid processLe Fort almost always present Lateral margin of nasal fossaUnique to Le Fort I Inferior orbital rimUnique to Le Fort II Zygomatic archUnique to Le Fort III * Rhea and Novelline. How to Simplify the CT Diagnosis of Le Fort Fractures. AJR Am J Roentgenol. 2005 May; 184(5):1700-5 Coronal CT: Pterygoid Plate Fractures Coronal CT: Zygomatic Arch Fractures

48. Le Fort Fractures: Pitfalls  Unilateral Requires a sagittal split of hard palate Results in widened maxillary arch  Combined Le Fort types Same side Different sides Don’t stop searching 27M Post-op internal fixation Coronal: Left Pterygoid Plate Fracture Coronal: Palate FractureCoronal: Nasal Fossa Fracture SSD: Unilateral Le Fort I & II

49. Le Fort Fractures: Pitfalls 61M Fall, head injury Coronal CT: Fractures Lateral Nasal Fossa Walls Axial CT: Fractures of Pterygoid Plates I I II SSD: Fracture of Orbital Rim  Unilateral Requires a sagittal split of hard palate Results in widened maxillary arch  Combined Le Fort types Same side Different sides Don’t stop searching

51. Smash Fractures  High energy fractures  Severe comminution  Multiple fracture planes  Multiple fracture patterns  Often associated with: Intracranial injury Temporal bone fractures C-spine injury 66M Self-inflicted gunshot wound 3D SSD: Facial Smash

52. 65M Attacked by grizzly bear Elements of: Zygomaticomaxillary Complex Fracture

53. 65M Attacked by grizzly bear Elements of: Naso-orbital Ethmoidal Fractures

54. 65M Attacked by grizzly bear Elements of: Orbital Blow Out

55. 65M Attacked by grizzly bear Elements of: Le Fort

57. LandmarkSignificance Medial orbital wall in “simple” nasal fractures Likely NOE complex fracture Nasofrontal duct Dysfunction leads to mucoceles May require frontal sinus obliteration Lacrimal fossa Landmark for medial canthal tendon attachment Zygomaticosphenoid suture Watch out for rotatory deformity Pterygoid plates Marker for transfacial injury Next look at… lateral walls nasal fossa, inferior orbital rims, zygomatic arches Orbital soft tissues Widen windows Look for foreign material