Mid face fractures by M77R5T

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									Lufadeju
   Introduction
   Epidemiology
   Anatomy of the mid face
       Boundary
       Bones
       Physical characteristics
       Reinforcement
       Relevant nerves and blood vessels
   Causes of mid face fractures
   Classification of mid face fractures
   Fracture lines
   A fracture may be defined as a sudden break in
    the continuity of bone.
   It may be complete or incomplete
   Fractures of the mid face are seen less frequently
    than fractures of the mandible
   However, the incidence is increasing due to
    increasing number of high speed transportation
    means.
   The result of epidemiologic studies of mid face
    fractures differ with the population density,
    politics, era, socioeconomic status of the
    population reviewed, and the institution in which
    the survey was performed
   Existing trends make it clear that mid face
    fractures are more frequently associated with
    motor vehicle and motorcycle accidents
   Usually associated with other facial fractures and
    other injuries like lacerations, orthopedic and
    neurologic injury
   Occur mostly in young men aged 16 to 40 years,
    especially between ages 21-25.
   The risk of sustaining such fractures increases as
    the age of the patient increases
   Boundaries-
       Superiorly – imaginary line drawn across the skull from
        the zygomaticofrontal suture of one side, across the
        frontonasal and fronto maxillary sutures to the
        zygomaticofrontal suture on the other side
       Inferiorly – the occlusal plane of the upper teeth. In an
        edentulous patient, the upper alveolar ridge
       Posteriorly – sphenoethmoidal junction, including the
        free margin of the pterygoid laminae of the sphenoid
        bone inferiorly
   Bones – 8 paired bones, 2 unpaired bones
     2 maxillae
     2 palatine bones
     2 zygomatic bones + their temporal processes
     2 zygomatic processes of temporal bones
     2 nasal bones
     2 lacrimal bones
     2 inferior conchae
     2 pterygoid plates of the sphenoid bone
     The ethmoid bone + it’s attached conchae
     The vomer
   Physical characteristics
       Bones are rarely fractured in isolation
       Comparatively fragile, and articulate in a complex fashion
       Maxilla makes up the greatest portion
       Fractures are usually comminuted
       These complex bones are so designed to withstand forces of
        mastication from below
       They are easily fractured by relatively small impact from
        other directions
       The nasal bones are least resistant, followed by the
        zygomatic arch, to forces from the front and the side, while
        the maxilla is sensitive to horizontal impact
   The majority of the skeleton of the middle third of
    the face is composed of wafer thin sheets of the
    cortical bone with stronger bony reinforcement
    comprising:
     The palate and alveolar process
     The lateral rim of the piriform aperture extending up via
      the canine fossa to the medial orbital rim and then to
      the glabella
     Zygomatic buttress and the connections to the inferior
      and lateral orbital margins and the zygomatic arch
     The orbital rims
     The pterygoid plates
   Anterior or canine pillars
       Starts in the region of the alveolar process of the
        canine, forms the lateral boundary of the anterior nasal
        aperture and continues as the frontal process of the
        maxilla to the frontal bone
   Middle or zygomatic pillars
       Starts in the region of the first molar, bends uo and out
        as the zygomaticoalveolar crest and zygomatic process
        of the maxilla, and continues up to end at the
        zygomatic process of the frontal bone
   Posterior or pterygoid pillars
       Pterygoid process of sphenoid bone
   Supraorbital rims with frontal bone
   Infraorbital rims
   Alveolar process
   Nervous supply –
       CN V2 – infraorbital, palatine branches, nasopalatine
        nerves
   Blood supply – third part of maxillary artery
   Typical causes include
       Direct violence
         RTA, Battery, fist fights, falls, blows from objects,
          occupational hazards
     Indirect violence
     Crush injuries
         Automobile accidents
         Aeroplane crashes
         Mining accidents
   Le Fort’s classification (1901)
       Le Fort I, II, III
   Erich’s classification (1942)
       Horizontal, pyramidal, transverse
   Classification based on relationship of fracture
    line to zygomatic bone
       Subzygomatic, suprazygomatic
   Classification based on level of fracture line
       Low, mid, high level fractures
   Rowe and Williams (1985)
       # not involving teeth and alveolus
         Central region
           # of the nasal bone and/or the nasal septum
           # of the frontal process of the maxilla
           # of the above which extend into the ethmoid bone (naso-
            ethmoid #s)
           # of the above which extend into the frontal bone (fronto-
            orbito-nasal #s)
         Lateral region
           #s involving the zygomatic bone, arch, and maxilla (zygomatic
            complex #s)
   #s involving the teeth and alveolar bone
       Dento alveolar
       Subzygomatic
         Le fort I
         Le fort II
       Suprazygomatic
         Le fort III
   Marciani’s classification (1993)
       Le fort I – low maxillary #s
         Ia – low maxillary #s/multiple segments
       Le fort II – pyramidal #s
         IIa - Pyramidal and nasal #s
         IIb – pyramidal and naso-orbito-ethmoidal complex #s
       Le fort III – craniofacial dysjunction
         IIIa – craniofacial dysjunction and nasal #
         IIIb – craniofacial dysjunction and NOE #
       Le fort IV – le fort II or III with cranial base #
         IV a - +supraorbital rim #
         IVb - +anterior cranial fossa and supra orbital rim #
         Ivc - +anterior cranial fossa and orbital wall #
   Rowe and Killey (1968)
       Type I – no significant displacement
       Type II - #s of the zygomatic arch
       Type III – rotation around the vertical axis
         Inward displacement of the orbital rim
         Outward displacement of the orbital rim
       Type IV – rotation around the longitudinal axis
         Medial displacement of the frontal process
         Lateral displacement of the frontal process
       Type V – displacement of the complex en-bloc
         Medial
         Inferior
         Lateral (rare)
       Type VI – displacement of the orbitiantral partition
         Inferiorly
         Superiorly (rare)
       Type VII – displacement of the orbital rim segments
       Type VIII – complex comminuted #s
   Rowe (1985) similar to that of Larsen and
    Thomsen (1968)
       Group A – stable #, showing minimal or no
        displacement and requiring no intervention
       Group B – unstable #, with grat displacement and
        disruption at the frontozygomatic suture and
        comminuted #s. Requires reduction and fixation
       Group C – stable #, other types of zygomatic #s, which
        require reduction but no fixation
   In 1961 Knight and North classified zygomatic
    fractures by the direction of displacement on a
    Waters’ view radiograph
    #s of the zygomatic complex involving the orbit
       Minimal or no displacement
       Inward and downward displacement
       Inward and posterior displacement
       Outward displacement
       Comminution of the complex as a whole
   #s of the arch not involving the orbit
       minimal or no displacement
       V- type in-fracture
       Comminuted #
   In 1990, Manson and colleagues proposed a method of
    classification based on the pattern of segmentation and
    displacement.
   Fractures that demonstrated little or no displacement
    were classified as low energy injuries. Incomplete
    fractures of one or more articulations may be present.
   Middle-energy fractures demonstrated complete fracture
    of all articulations with mild to moderate displacement.
    Comminution may be present .
   High-energy injuries were characterized by comminution in
    the lateral orbit and lateral displacement with
    segmentation of the zygomatic arch.
   For ordinary practical purposes in discussing
    signs and symptoms and plannimg treatment, a
    simpler classification is adequate
     Dento alveolar #s
     Zygomatic complex #s
     Nasal complex #s
     Le fort I #s
     Le fort II #s
     Le fort III #s
     Extended Le fort #s
   Zygomaticofrontal suture – lateral canthus of the
    eye
   Zygomatucotemporal suture – lateral side of the
    face
   Zygomaticomaxillary suture – infra orbital margin
   Zygomaticosphenoid suture – not easily
    accessible
   Split across
   Comminuted
   With/without displacement
   As with all fractures, NOE fractures are classified
    as unilateral or bilateral, open or closed, and
    simple or comminuted. Three types of NOE
    fractures have been well described.
   Type I fracture maintains the attachment of the
    MCT to a large single nasoethmoidal fracture
    segment; repairing this type of fracture is
    straightforward.
   Type II fracture shows more comminution yet
    maintains the attachment of the medial canthus
    to a sizable bony segment.
   Type III fractures display severe comminution with
    possible avulsion of the MCT from its bony
    attachment
   Aka horizontal/guerin’s/ floating/ low level/
    subzygomatic fracture
   # line – commences at a point on the lateral
    margin of the nasal aperture, passes above the
    nasal floor, laterally above the canine fossa and
    traverses the lateral antral wall, dipping down
    below the zygomatic buttress and then inclines
    upward and posteriorly across the
    pterygomaxillary fissure to fracture the lower
    1/3rd of the pterygoid laminae.
   it also passes along the lateral wall of the nose
    and the lower 1/3rd of the nasal septum to join
    the lateral # behind the tuberosity
   Typically bilateral, with fracture of lower third of
    nasal septum, but may be unilateral
   May occur as a single entity or in association with
    Le Fort II & III #s
   Usually caused by violent force applied over a
    more extensive area above the level of the teeth
   May also be caused by a blow to the lower jaw
   Slight swelling of lower part of face+upper lip
   Ecchymosis in labial and buccal vestibule, contusion
    of skin of upper lip, laceration of upper lip and intra
    oral mucosa
   Bilateral epistaxis or nasal bleeding
   Mobility of upper dentoalveolar portion of the jaw
   Disturbed occlusion & difficulty in mastication
   Pain while speaking and moving jaw
   Cracked pot percussion note of maxillary teeth
   Fracture of the cusps of the cheek teeth
   Impaction of entire fragment, giving a classical open
    bite
   0° occipitomental (0° OM)
   30° occipitomental (30° OM)
   True lateral skull (brow-up)
   Closed reduction
   Place upper & lower arch bars and do IMF
   Internal fixation via internal suspension
   Circumzygomatic wiring or external fixation
   For unilateral #s, do a closed reduction and
    immobilization of the jaw
   Aka pyramidal/ subzygomatic fractures
   # line runs below frontonasal suture from the thin
    middle area of the nasal bones down on either
    side, crossing the frontal process of the maxillae
    into the medial wall of each orbit, and passing
    across lacrimal bones immediately behind the
    lacrimal sac. From this point, it passes downward,
    forward and laterally crossing the inferior orbital
    margin slightly medial or through the infraorbital
    foramen.
   It then runs downwards and backwards across
    the lateral wall of the antrum below the ZM
    suture, and divides the pterygoid lamina at its
    middle third
   Seperation of the block of the midface from the
    base of the skull is completed via the nasal
    septum and may involve the floor of the anterior
    cranial fossa
   Usually caused by a violent force in an anterior
    direction sustained by the central region of the
    middle 1/3rd of the facial skeleton over an area
    extending from the glabella to the alveolar margin
   Force may be delivered at the level of the nasal
    bones
   Ballooning or moon face
   Bilateral circumorbital oedema and ecchymosis
   Bilateral subconjuctival hemorrhage confined to the medial 1/3rd of
    the eye and enopthalmos
   Depressed nasal bridge
   Shortening of the face with anterior open bite
   Dish shaped face
   Bilateral epistaxis
   Masticatory and speech difficulty
   Loss of occlusion
   Airway obstruction
   Surgical emphysema
   CSF leak
   Step deformity of infraorbital margins
   Anaesthesia &/or paresthesia of the cheek
   0° occipitomental (0° OM)
   30° occipitomental (30° OM)
   True lateral skull (brow-up)
   Aka transverse / suprazygomatic/high level fracture
   # line runs from near the Fn suture transversely
    backwards, parallel with the base of the skull and
    involves the full depth of the ethmoid bone, including
    the cribriform plate. Within the orbit, the # line passes
    below the optic foramen into the posterior limit of the
    inferior orbital fissure.
   From here, it extends in 2 directions:
     Posteriorly across the PM fissure to # the root of the
      pterygoid laminae
     Anteriorly across the lateral wall of the orbit seperating the
      zygomatic bone from the frontal bone
   Usually caused by trauma inflicted over a wide area at
    the orbital level
   Force is usually applied from a lateral direction with
    severe impact
   Initial impact is taken by the zygomatic bone,
    resulting in depressed fracture
   Because of the severe impact, the entire middle face
    thus hinges about the fragile ethmoid bone and the
    impact will be transmitted on the contralateral side
    resulting in laterally displaced zygomatic # of the
    opposite side (craniofacial dysjunction)
   Mobility of the entire middle facial skeleton as a block can be felt on gentle
    manipulation
   Panda facies within 24 hours
   Racoon eyes
   Bilateral subconjuctival oedema without posterior limit
   Tenderness and separation at FZ sutures causing lengthening of the face and
    lowering of the ocular level
   Unilateral or bilateral hooding of the eyes
   Dish face deformity
   Enopthalmos, diplopia od impairment of vision, blindness
   Epistaxis, CSF rhnorrhoea
   Flattening, widening and deviation of the nasal bridge
   Posterior gagging, anterior open bite
   Lateral displacement of midline in upper jaw
   Gagging of occlusion of molars at one side and posterior open bite at the
    other side due to lateral displacement of #
   0° occipitomental (0° OM)
   30° occipitomental (30° OM)
   True lateral skull (brow-up)
   Coronal section tomography
   CT +/- 3-D reconstruction

								
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