ct of maxillofacial injuriesh24-files.s3.amazonaws.com/110213/295785-xenzz.pdfnaso-orbital-ethmoid...
TRANSCRIPT
1
CT of Maxillofacial Injuries
Stuart E. Mirvis, M.D., FACRDepartment of Radiology
University of Maryland School of Medicine
Viking 1 1976 MGS 2001
Technology changes the diagnosis
2
Technologic Evolution
Struts and buttresses
Topics to Cover
Orbital fracturesNaso-orbital ethmoid (NOE)Zygomaticomaxillary complex – (ZMC)Le Fort midface patternsOcularOcularMandibleBoom!
3
Facial StrutsFacial Struts Posterior coronal strutsconsisting of posterior wall of maxillarysinus (1) and pterygoid plates (2)
Anterior coronal struts consisting of frontal (1 ), zygomaticofrontal (2), nasofrontal (3), anterior maxillary (4), anterior alveolar (5) components.
Sagittal struts consisting of median (1 ), parasagittal(2), and lateral (3) parts
Horizontal struts superior (1), middle (2),and inferior (3) parts.
Gentry LR, et al. High-Resolution CT Analysis of Facial Struts in Trauma: 1. Normal Anatomy. AJR 140:523-532, March 1983
Concept of Facial ButtressesConcept of Facial Buttresses
Major support for facial skeleton to maintain form and function (I‐beams)maintain form and function (I‐beams)
Attach directly or indirectly to skull base or cranium
3 vertical and 3 horizontal
Buttresses accommodate screw fixation
Maintain facial width and height
Establish functional support (orbits and teeth)
Hopper RA, Salemy S, Sze RW. Diagnosis of MidfaceFractures with CT: What the Surgeon Needs to Know. RadioGraphics 2006; 26:783–793
4
Highlights of Facial Anatomy - Orbit
Orbital sutures and thin orbital bony plates allow suture diastasis and fractures of thin bone to absorb
impacting energy.
This mechanism plus orbital fat and muscles cushions the globe and preserves vision in high-energy
impacts to the orbit.
Orbital BlowOrbital Blow--out Fractures:out Fractures:Significant Imaging FeaturesSignificant Imaging Features
E id f l f t t t ( iti / h fEvidence of muscle or fat entrapment (position/shape of muscle)Pure or impure fracture (?intact inferior orbit rim)Orbital hematoma (up to 24% orbital injuries)Complications: enopthalmous, diplopia, hypoesthesia Size (area) of floor defect or associated fracturesCalculations of blow‐out fractures of the orbital floor by 3D‐CTCalculations of blow‐out fractures of the orbital floor by 3D‐CT
and 2D‐CT method are accurate for assessing the area of fracture and the volume of herniated tissue*
*Ploder O, 2D- and 3D-based measurements of orbital floor fractures from CT scans. J Craniomaxillofac Surg. 2002
5
Orbital blow-out fracture
Orbit BlowOrbit Blow--out Fractureout Fracture
6
Herniated Inferior Rectus
Orbit Blow-out Fracture
7
Medial orbital wall fracture
Isolated or associated 20-40% with floorIsolated or associated 20 40% with floor fracture
More common to cause orbital emphysema
Rarely surgically repaired
Complications: Horizontal gaze palsy, enopthalmous, epistaxis
Medial Medial Orbital Orbital
BlowBlow--out out FracturesFractures
8
Medial wall fracture -entrapment
Medial blow-out with herniation
9
Orbital Blow-in fracture
Orbital Blow-in fracture: MRI with brain herniation
10
Orbital Blow-up fracture
RareRare
Orbital roof fragments explode into frontal lobe
Typical – dural tears and CSF leak
Frontal sinus involvement commonFrontal sinus involvement common
Orbital “blow-up” fracture
11
Orbital Blow-up fracture
Naso-orbital-ethmoid Complex
Nasal bridge, lower frontal sinus, medial orbits
Comminution, depression, and lateral spread of bones
Soft tissue injury; medial canthal ligament, lacrimal drainage nasofrontal sin sdrainage, nasofrontal sinus
Usually associated fracture patterns
12
Naso-orbital Ethmoid Fractures
N= 21N= 21Clinical findings:
Widened intercanthal distance (71%)Increased nasofrontal angle (28%)Epistaxis (100%) Visual disorder (62%)Visual disorder (62%)Cerebrospinal rhinorrhea (33%) Enophthalmos (23%)Facial paralysis (14%)
Naso-orbital-ethmoid Complex
13
Naso-orbital-ethmoid Complex
NOE and repair
14
NasomaxillaryFracture
Kicked by horse
Sagittal mid-face pattern
15
Zygomatic-maxillary Complex (ZMC)
Impact on malar eminence
4- point fracture
Displaces posterior and medially
Simple type vs hi-gradeSimple type vs. hi-grade variant
Zygomatic-maxillary Complex
(ZMC)
Al i lAlways involves orbital floor
May involve medial orbit wall
Lateral canthal ligamant and inferiorligamant and inferior orbital nerve
Coronoid process impact
16
Zygomatic-maxillary Complex (ZMC) –
hi-grade
Zygomatic-maxillary Complex (ZMC) Hi-grade
17
Complex ZMC
yOrbital Apex Syndrome
Optic neuropathy and ophthalmoplegiaOptic neuropathy and ophthalmoplegiaLoss of cranial nerves II, III, IV, opthalmic division of V, and VI Blindness, fixed dilated pupils, proptosis, ptosisC i fl t i f ti l tiCauses: inflammatory, infectious neoplastic, iatrogenic/traumatic, and vascular conditions
18
LeFortLeFort Fracture PatternsFracture PatternsDescribed as symmetric mid‐face lines of weakness ‐
experimental
Often asymmetric clinically and combined with ZMC, NOE
Al i l t id l t f tAlways involves pterygoid plate fractures
Higher energy usually leads to higher grade
Any pattern of Lefort 1,2,3 fractures can occur
In 1901 the French surgeon, Dr. Rene LeFort (1869-1951), French army surgeon from Lille, published his results from pexperiments aimed to describe fracture patterns. He performed a number of experiments on cadaver heads. These experiments included blows to the cadaver head at different angles with a wooden club. He also hurtled the head against stationary objects and kicked it in various places in the face
19
LeFort Fracture Patterns
LeFortLeFortFracture 1Fracture 1
Fracture all 6 walls of maxillary sinuses
Floating palate
Typically: nasal septum & maxillary
l inasal spine
Airway compromise -rare
20
LeFort Fracture I +
LeFortLeFort II Fracture PatternsII Fracture PatternsMobile nose and maxilla (a portion of the upper
transverse maxillary buttress [orbital rim] is involved in mobile segment)Fx. Lateral maxillary sinus, medial orbital floor,
nasal bridge, pterygoids (pyramidal)g , p yg (py )
Soft tissues: medial orbit, infraorbital nerve
ZygomaticomaxillaryFrontomaxillary
21
LeFort 2
LefortLefort II and II and NOENOE
22
Unilateral Unilateral LeFortLeFort 2/32/3
LeFort Fracture III
23
LeFort Fracture III
Lefort II/III: highly comminuted
24
Combined LeFort Fracture Pattern - Smash
25
26
GSW through the medial orbit – monocular
blindness
27
Mandibular Fractures
Fracture Type Prevalence
Mandibular Fractures
Body 30 - 40 %
Angle 25 - 31 %
Condyle 15 - 17 %
Symphysis 7 - 15 %
Ramus 3 - 9 %
Al l 2 4 %Alveolar 2 - 4 %
Coronoid process 1 - 2 %
28
Mandibular Angle Fracture
29
30
ORIF angle/body fx –oops!
Mandibular Fracture – Dislocation
31
Mandibular Fracture - Dislocation
Mandible fracture-
dislocation (sagittal split)
32
LeFort I/II/III: Comminuted mandible fractures
Bilateral TMJ dislocation - yawning
33
Attempted suicide: Bit blasting cap
GSW: Facial explosion
34
Fibular graft reconstitutingreconstituting
maxillary contour