Disclosures: Facial Trauma ! None Sara R. Nace, MD American Society of Head & Neck Radiology 50th Annual Meeting Thursday, September 8th, 2016 Objectives Facial Bones ! Briefly review role of facial bones and structural pillars ! Societal importance, perception ! Discuss diagnosis of facial trauma (Multi-detector CT) ! Communication ! Review key points of “simple” midface fractures: nasal bone, ! Nutrition maxilla/palate, zygoma and orbit ! Housing and protection of proximal airway and organs of special ! Identify complex midface fracture patterns, relevant classification sense systems & commonly associated complications ! “Cushion” for the neurocranium and cervical spine • Le Fort (I, II, & III) • Nasoethmoidal • Zygomaticomaxillary Complex Fractures Facial Buttresses Facial Buttresses ! Thickened skeletal buttresses evolved in part to distribute vertical & axial (grinding) masticatory forces Sagittal ! Compartmentalize the face and provide attachment points for soft PTERYGO- NASO- • Nasomaxillary (medial) MAXILLARY MAXILLARY tissue structures • Zygomaticomaxillary Sagittal Axial Coronal (lateral) • Pterygomaxillary ZYGOMATICO • Nasomaxillary (medial) • Frontal bar • Anterior plane -MAXILLARY (posterior) • Zygomaticomaxillary • Upper maxillary • Posterior plane • +/- Vertical mandible (lateral) • Lower maxillary VERTICAL • Pterygomaxillary • +/- Skull base MANDIBLE (posterior) • +/- Vertical mandible Facial Buttresses Facial Buttresses FRONTAL BAR Axial • Frontal bar Coronal • Upper maxillary • UPPER • Anterior plane Lower maxillary MAXILLARY • +/- Skull base • Posterior plane LOWER MAXILLARY ANTERIOR PLANE POSTERIOR PLANE Diagnosis in Facial Trauma Diagnosis in Facial Trauma ! Multi-detector CT is imaging of choice ! Clinical examination and routine radiographs are inferior • Clinically, fractures are obscured by soft tissue injury, altered level of consciousness, and life threatening injuries to remainder of body • Up to 25% patients needed surgical intervention of nasal bone fracture despite negative plain films* • 43-78% orbital wall fractures could be diagnosed on plain film Clayton MI, Lesser TH. The role of radiography in the management of nasal fractures. J Laryngol Otol 1986; 100: 797-801. Diagnosis in Facial Trauma Objectives ! Multi-detector CT is imaging of choice ! Briefly review role of facial bones and structural pillars • Thin section axial bone algorithm images with reformations. • Demonstrates soft tissue injury, hemosinus, foreign bodies ! Discuss diagnosis of facial trauma (Multi-detector CT) • Performed in conjunction with CT head, cervical spine ! Review key points of “simple” midface fractures: nasal bone, maxilla/palate, zygoma and orbit • Three-dimensional images in assessment of complex facial deformities, preoperative planning, and patient consultation ! Identify complex midface fracture patterns, relevant classification • Parmar HA, Ibrahim M, Mukherji SK. Optimizing Craniofacial CT Technique. systems & commonly associated complications Neuroimag Clin N Am 2014; 24: 395-405. • Le Fort (I, II, & III) • Nasoethmoidal • Zygomaticomaxillary Complex Fractures Nasal Bone Fracture Nasal Bone Fracture ! Manifestation dependent on direction and degree of injury force ! The most common central midface fracture, likely • Lateral impact mechanism (2/3rd) > frontal injury underrepresented ! Involvement of bony vs. cartilaginous structures ! Manifestation dependent on direction and degree of injury force • Lateral impact mechanism (2/3rd) > frontal injury • Look for/ report on nasal septal hematoma- potential complications include infection and/or pressure necrosis. Nasal Bone Fracture Fracture of Maxilla/Palate • Look for/ report on nasal septal hematoma- potential complications include infection and/or pressure necrosis. ! Alveolar fracture is the most common isolated maxillary fracture • Mechanism = blow to mandible, pushing teeth upward/outward • Associated displacement / devitalization of teeth Anterior Posterolateral * Hendrickson M, Clark N, Manson PN, et al. Palatal fractures: classification, patterns and treatment. Plast AXIAL Reconstr Surg 1998; 101 (2): 319-332. Fracture of Maxilla/Palate Fracture of Maxilla/Palate ! Palatal Fracture Classification* Type I- Alveolar • Type I- Alveolar (anterior, posterolateral) Anterior • Type II- Sagittal • Type III- Parasagittal • Type IV- Para-alveolar • Type V- Complex • Type VI- Transverse * Hendrickson M, Clark N, Manson PN, et al. Palatal fractures: classification, patterns and treatment. Plast Reconstr Surg 1998; 101 (2): 319-332. CORONAL SAGITTAL AXIAL MIP Fracture of Maxilla/Palate Fracture of Maxilla/Palate ! Sagittal palatal fractures ! Parasagittal & para-alveolar palatal fractures • Fracture pattern primarily in pediatric population • Fracture extension along thinner bone, lateral to the vomerine attachment to the maxilla • Palatal suture ossifies between the second and third decade • Association with more complex Le Fort type injury patterns Type II- Sagittal Type III- Parasagittal Type IV- Para-alveolar Fracture of Maxilla/Palate Fracture of Maxilla/Palate Type III- Parasagittal Type III- Parasagittal CORONAL AXIAL AXIAL MIP SAGITTAL AXIAL AXIAL MIP Fracture of Maxilla/Palate Fracture of Zygomatic Arch Type V- Complex Type VI- Transverse ! Isolated fractures • Typically 2 fractures segments with medial/ inferior displacement • Potential impingement on temporalis musculature or coronoid process AXIAL AXIAL Orbital Fracture Orbital Checklist ! “Blow-out” and “Blow-in” fractures (pure vs. impure) ! Mechanisms: Hydraulic and bone conduction theories of orbital blow-out fractures* • Blow too large to enter orbit, resulting in forces transmitted to bony and soft Intraocular tissue structures. Hemorrhage Globe Rupture ! Globe is typically undamaged • Checklist: anterior chamber, position of the lens, posterior globe segment, Foreign Bodies orbital apex and foreign bodies Retrobulbar Waterhouse N, Lyne J, Urdang M, et al. An investigation into the mechanism of orbital blowout fractures Br J Plast Hematoma Surg 1999; 52: 607-12. Lens Injury (Fracture-Subluxation) Orbital “Blow-out” Fracture Orbital Blow-Out Fracture ! Orbital Floor ! Mechanisms: Hydraulic and bone conduction • Fractures in middle third, near infra-orbital canal • Blow too large to enter orbit, resulting in forces transmitted to bony and soft tissue structures. • Trapdoor, hinged ! Medial Wall • Fractures less predictable due to reinforcement by ethmoid sinus • Emphysema, adjacent fat effacement is helpful to distinguish acute injury Hydraulic Theory Bone Conduction Theory Orbital Blow-Out Fracture Orbital Blow-Out Fracture ! Mechanisms: Hydraulic and bone conduction • Blow too large to enter orbit, resulting in forces transmitted to bony and soft tissue structures. 2 Fracture types: 1. Small fracture, involving the anterior to mid medial floor of the orbit. Herniation of contents is unusual. AXIAL Waterhouse N, Lyne J, Urdang M, et al. An investigation into the mechanism of orbital blowout fractures Br J Plast Surg 1999; 52: 607-12. Bone Conduction Theory CORONAL SAGITTAL Orbital Blow-Out Fracture Orbital Blow-Out Fracture AXIAL AXIAL CORONAL SAGITTAL Orbital Blow-Out Fracture Orbital Blow-Out Fracture ! Mechanisms: Hydraulic and bone conduction • Blow too large to enter orbit, resulting in forces transmitted to bony and soft tissue structures. 2 Fracture types: 2. Large fracture, involving the floor and medial orbital wall. Herniation of contents is frequent. Hydraulic Theory CORONAL SAGITTAL Orbital Blow-Out Fracture Orbital “Blow-out” Fracture ! Clinically: • Upward gaze palsy due to extraocular muscle entrapment • Herniation of fat alone leads to muscle entrapment due to fibrous attachments to adjacent musculature! • Diplopia (hemorrhage, edema, emphysema) • Reduced visual acuity (globe injury, hematoma, emphysema, optic nerve injury) • Injury to maxillary division of trigeminal nerve (V2) CORONAL AXIAL Orbital “Blow-out” Fracture Orbital Blow-Out Fracture ! Indications for surgery: • Chronic enophthalmos is related to sizeable fracture defect with fat herniation. Identify prospectively! • Muscle entrapment and acute enophthalmos (fracture fragments > 1 cm in size) • Proptosis resulting in posterior globe tenting is an ophthalmologic emergency • Chronic enophthalmos is related to sizeable fracture defect with fat herniation. Identify prospectively! ! Alloplasts reconstruct orbital floor CORONAL AXIAL AXIAL Orbital Blow-Out Fracture Orbital Blow-In Fracture ! Orbital Floor • Rare. Fracture fragments may impinge on extraocular musculature or globe • Risk of globe laceration CORONAL AXIAL AXIAL CORONAL CORONAL Orbital Blow-in Fracture Orbital Roof & Frontal Sinus Fracture ! Orbital Roof • Mechanism: Direct blow to forehead, with fracture fragments displaced inward • Association with skull (70%) and frontal sinus (55%) fractures, IC hemorrhage • Depressed fracture +/- subperiosteal hematoma can impinge on upper globe, clinically mimicking upward gaze palsy. CORONAL • Unique complications: dural tear with CSF leak or cephalocele, extension of fracture into orbital apex AXIAL CORONAL Orbital Roof & Frontal Sinus Fracture Frontal Sinus Fracture ! 5-15% maxillofacial trauma ! Mechanism: Direct trauma versus extension from calvarium; requires 800-2200 lbs of force! ! Treatment: ! Non-displaced are treated conservatively ! Anterior table fractures are treated with reduction/ stabilization (2/3rds) ! Frontal recess obstruction is treated with sinus obliteration ! Comminuted/ displaced anterior-