ct of maxillofacial trauma
DESCRIPTION
post graduate lectureTRANSCRIPT
DR.ANILRAJ K.K, MD,DNB.DMRDPROFESSOR AND HODTDMCH,ALAPUZHA
CRANIO FACIAL TRAUMA –COMMON CLINICAL INDICATION
INTRODUCTION OF MD CT AND ADVANCES IN IMAGE POST PROCESSING PROVIDE CRITICAL ANATOMICAL DETAILS WITH REQUIRED EFFICIENCY
CHALLENGES FOR RADIOLOGIST-DETECT INJURIES AND DEMONSTRATE THOSE INJURIES TO CLINICIAN / SURGEON
CRANIOFACIAL ANATOMY
THREE DIMENSIONS Recognize bony structures Functional dimension in terms of struts
and buttresses General relationship between face and
skull base
Osseous anatomy-supraorbital Continuation of frontal calvarium (orbital
plate of frontal bone on both sides) Frontal sinuses –posterior table fracture
significant NEO REGION-junctional point of frontal
sinus and calverium meet nasal bridge anteriorly and in turn joining with cribriform plate and ethmoid labrynth posteriorly
Union of upper facial skeleton with anterior skull base
ORBIT
ROOF- orbital plate of frontal bone+cribriform plate + lesser wing of sphenoid posteriorly
Supra orbital notch-trigeminal branch MEDIAL WALL-frontal proces of maxilla,lacrimal
bone,orbital plate of ethmoid(LP),sphenoid LATERAL WALL- posteriorly by GWS,anteriorly
by zygoma FLOOR- orbital surface of maxilla and zygoma infra orbital foramen 3 FISSURES/FORAMEN
MID FACE-maxilla, nasal bones,nasal cavity
ZYGOMA- frequently fractured, succesful surgery means reestablishment of normal dimension and contour of zygomatic arch
Inferior margin –maxillary alveolar ridge + teeth along the periphery and hard palate in the centre
MANDIBLE- synphysis,body,angle, ramus,anterior coronoid process and posterior condyle
Vulnerable points- condyle neck,angle, mental foramen,sites of impacted tooth
STRUTS AND BUTTRESES
First described by GENTRY IN 1983 Network of vertically and horizontally
oriented –in all 3 planes 3HORIZONTAL- Superior-orbital roof-cribriform plate-
orbital roof Middle-orbital floor-zygomatic arches Inferior-hard palate 5 VERTICAL- 1 midline-nasal septum 2 medial sagital –medial wall of orbits and
maxillary sinus- pterygoid plates
Struts and buttresses-contd. 2 lateral sagital-lateral wall of orbits
and zygomatic arches 2 CORONAL- Anterior strut- anterior surface of
facial skeleton at NEO region with frontal bone
Posterior strut- posterior walls of maxillary sinuses with pterygoid plates
Site of union between facial skeleton and skull base Roof of orbits- frontal calverium
Midface- frontal process of zygoma- FZS
Temporal process of zygoma- ZTS Most impotant and posterior-
pterygoid plate of sphenoid with posterior wall of maxillary sinuses just above maxillary alveolar ridge and just below the pterygopalatine fossa
classification
By integrating the strut and buttresses concept with understanding of the relationship of facial skeleton with skull base ,a system statifies most fractures into 3 main catogories- also serving a functional framework for the injuries+ fairly well correlating with the theraputic decision making
SOLITARY-simple/single bony wall COPLEX STRUT #- relationship between F.S and
SB partially severed unilaterally or bilaterally,needs open reduction to avoid cosmetic deformity
TRANSFACIAL-
classification
SOLITARY STRUT Isolated orbital floor,medial wall or rim Isolated zygomatic arch Isolated frontal or maxillary sinus wall Nasal arch COMPLEX STRUT Nasoethmoidal-orbital,nasomaxillary Zygomaticomaxillary-ZMC TRANSFACIAL-Lefort I,II,III AND SMASH# MANDIBLE
BLOW OUT FRACTURE
Pure blowout- acute rise in the intra orbital pressue- protective mechanism to maintain integrity of globe
Medial orbital floor,inferior medial wall or combination
Impure- associated with other # -orbital rim ,zygoma,transfacial structures
Clinical- infraorbital nerve injury- numbness of cheek, upper lip and anterior maxillary teeth
Diplopia-entrapment of IR Herniation of fat which may be tetherd to
fat
Blow out fracture-contd 3rd nerve branch injury affecting IO Trauma to IR-impairment of contractility MEDIAL BLOWOUT- Injury /entrapment of MR Associted opacification of ethmoid air cells LATERAL BLOWOUT-/BLOW IN FRACTURE
OF ROOF- Less common –associted with # supra
orbital region. Frontal sinuses and calverium
CORONAL IMAGING
Blow out #-complications
ENOPHTHALMOS- Displacement of orbitalsoft tissues
into maxillary or ethmiod sinus Artophy of orbital fat and scarring
within fat #fragments > 2cm squre area / that
are displaced > 3cm- potential surgical indication
Solitary strut
ISOLATED ZYGOMATIC ARCH-due to focussed trauma
Non displaced /displaced inward or outward Surgery for cosmetic reasons Inward displacement can impinge coronoid
procees-can limit mandibular motion ISOLATED FRONTAL/MAXILLARY SINUS WALL NASAL FRACTYRES- most common ,50% Comminuted or displaced
COMPLEX STRUT#
NEO/NASOMAXILLARY 4 facial struts converge in this region-single
medial and 2 medial paramedian + superior horizontal
Always complex and comminuted Always involve 2 out of 4 struts Involvement of nasal bone +frontal process of
maxilla-free movement 50% unilateral Fragments displaced posteriorly-cribrifom plate Displaced laterally- NLD,NFD,Ocular injuries
COMPLEX STRUT #
ZYGOMATICOMAXILLARY COMPLEX-ZMC Zygoma-inferolateral margin of orbit Point of intersection of lateral
paramedian ,middle horizontal and anterior coronal struts
TRIPOD/TRIMALAR #-dysjunction of zygoma #lateral orbital rim in the vicinity of ZFS #inferior orbital rim+ orbital floor Lateral orbital wall –ZSS #zygomatic arch (ZTS) #anterior and posterior wall of maxillary sinus
ZMC FRACTURES-contd
INCOMPLETE-one of osseous connection intact
NON DISPLACED- incomplete fracturing- ZFS DISPLACED /ROTATED Inferiorly/laterally/posteriorly Exo/enophthalmos if orbital volume affected Displacement at ZFS- open reduction Inferior displacement- distortion of lateral
canthus-cosmetic deformity Infra orbital nerve/IR injury less frequent Impingement of coronoid process
TRANSFACIAL #
RENE LE FORT in early 1900 All are complex –involve multiple struts –
need open reduction and fixation All have potential to result in facial
deformity All represent some degree of
disconnection between facial skeleton and skull base
Single most charecteristic feature is involvement of pterygoid plates
Le Fort type I
Horontally oriented invoving inferior portion of maxillary antra , medial wall of maxillary sinus and inferior nasal septum, posteriorly through pterygoid plates + # hard palate
Palate along with maxillary ridge and alveolus of maxilla- free fragment –FLOATING PALATE
Mid face swelling, echymosis/naso pharyngeal bleed
Le Fort type II
Most common among le fort # Involves orbits and upper nasal cavity
structures 3D triangular configuration –PYRAMID # Apex at nasal bridge +fronto naso
ethmiodal complx Lateral side wall- medial orbital wall,
orbital floor, inferolaterally anterior and posterolateral wall of maxillary sinus terminating to pterygoid plates
Central pyramid displaced posteriorly- DISH FACE DEFORMITY
Le Fort type II-contd
No involvement of medial wall of maxillary sinus,inferiornasal septum,hard palate,lateral orbital wall,zygomatic arches
Severe cosmetic deformity Malocclusisn Infra orbital nerve injury
Lefort type 3
Craniofscial dysjunction Le fort 2 + lateral orbital wall and
zygomatic arches
SMASH FRACTURES High energy injuries causing severe
communition ,usually associted with IC bleed, temporal bone # and cervical spine injuries
MANDIBULAR FRACTURE
50% SOLITRY,50% MULTIPLE SIMPLE-no communication to oral
cavity/skin COMPOUND COMMINUTED-multiple fragments IMPACTED-foreshortening + restricted
movements GREEN STICK- only one side of cortex PATHOLOGIC-underlying osseous disease
Mandibular fracture -contd Commonest site- condyle/sub condylar area INTRA CAPSULAR- less common, in
children,secondary OA changes EXTRACAPSUALR-unilateral> bilateral Unilateral associated with contralateral
angle# Rarely force of impact of condyle
transmitted to temporal bone –carotid canal –ICA injury
1 mm axial ,MPR /curved reformats similar to OPG
Radiological evaluation and interpretation
Plain films –limited role-screening Conventional CT-Direct Coronal
Orbital roof and floor Cribriform plate Plannum sphenoidale Hard palate SPIRAL CT/ MD CT HR images in seconds High quality axial and MPR,curved 2D and 3D
with single tissue(bone) /multiple tissue(bone ,fat and muscle)
IMAGING GOALS
SCREEN FOR INJURY- plain film occipitomental 15
3-5 mm sections CT DETECTING AND DIAGNOSING – high
quality axial, MPR including curved reformats
DEPICTION OF INJURY-3D – surgical planning and
Patient education Advances in 3D- volumetric assessments Advanced volume rendering techniqus Virtual surgery
MDCT- additional sagital and oblique coronal- orbital floor/mandibular #
Curved reformats- condyle /coronoid orocess
NEW HORIZONS INTRA OPERATIVE CT REAL TIME 3D New stabilization /fixation materials –
non metallic and resorbable
SURGEONS PERSPESTIVE
Ct added a 3rd dimension to the craniofascial trauma analysis- ct guided surgery
CT acurately visualizes the fracture Shows comminuted parts Direction of displacement Associted soft tissue injury Catogorized and designated as
low,mid,high velocity Relationship of fracture fragments to
critical soft tissues like optic nerve/extra ocular muscles
Alterd orbital volume
Sublle TM joint effusion or haemoarthrosis
ROLE OF PLAIN RADIOGRAPHY Fractures in proximity to the dentition, Teeth root and related structures Root tip fractures Peri apical pathologies Periodontal/dental pulp diseases Post.op assessment of fixation
CONCLUSION
Craniofascial trauma remains a prevalent condition nowadays and typically requires intense and immediate clinical decision – that is largely dependant on radiologic detection and depiction of injuries
Recent advances in spiral CT and computer post processing technologies made CT to evaluate CFT patients thouroughly and efficiently and become the IMAGING MODALITY OF CHOICE
THANK YOU