Ct of maxillofacial trauma

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Transcript of Ct of maxillofacial trauma


2. CRANIO FACIAL TRAUMA COMMONCLINICAL INDICATION INTRODUCTION OF MD CT AND ADVANCESIN IMAGE POST PROCESSING PROVIDECRITICAL ANATOMICAL DETAILS WITHREQUIRED EFFICIENCY CHALLENGES FOR RADIOLOGIST-DETECTINJURIES AND DEMONSTRATE THOSEINJURIES TO CLINICIAN / SURGEON 3. CRANIOFACIAL ANATOMY THREE DIMENSIONS Recognize bony structures Functional dimension in terms of struts and buttresses General relationship between face and skull base 4. Osseous anatomy-supraorbital Continuation of frontal calvarium (orbitalplate of frontal bone on both sides) Frontal sinuses posterior table fracturesignificant NEO REGION-junctional point of frontalsinus and calverium meet nasal bridgeanteriorly and in turn joining with cribriformplate and ethmoid labrynth posteriorly Union of upper facial skeleton with anteriorskull base 5. 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,lacrimalbone,orbital plate of ethmoid(LP),sphenoid LATERAL WALL- posteriorly by GWS,anteriorly byzygoma FLOOR- orbital surface of maxilla and zygoma infra orbital foramen 3 FISSURES/FORAMEN 6. MID FACE-maxilla, nasal bones,nasal cavity ZYGOMA- frequently fractured, succesfulsurgery means reestablishment of normaldimension and contour of zygomatic arch Inferior margin maxillary alveolar ridge + teethalong the periphery and hard palate in thecentre MANDIBLE- synphysis,body,angle,ramus,anterior coronoid process and posteriorcondyle Vulnerable points- condyle neck,angle, mentalforamen,sites of impacted tooth 7. STRUTS AND BUTTRESES First described by GENTRY IN 1983 Network of vertically and horizontally oriented inall 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 maxillarysinus- pterygoid plates 8. 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 9. Site of union between facialskeleton 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 10. classification By integrating the strut and buttresses concept withunderstanding of the relationship of facial skeletonwith skull base ,a system statifies most fracturesinto 3 main catogories- also serving a functionalframework for the injuries+ fairly well correlatingwith the theraputic decision making SOLITARY-simple/single bony wall COPLEX STRUT #- relationship between F.S and SBpartially severed unilaterally or bilaterally,needsopen reduction to avoid cosmetic deformity TRANSFACIAL- 11. 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 12. BLOW OUT FRACTURE Pure blowout- acute rise in the intra orbitalpressue- protective mechanism to maintainintegrity of globe Medial orbital floor,inferior medial wall orcombination Impure- associated with other # -orbital rim,zygoma,transfacial structures Clinical- infraorbital nerve injury- numbness ofcheek, upper lip and anterior maxillary teeth Diplopia-entrapment of IR Herniation of fat which may be tetherd to fat 13. 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 OFROOF- Less common associted with # supra orbitalregion. Frontal sinuses and calverium CORONAL IMAGING 14. Blow out #-complications ENOPHTHALMOS- Displacement of orbitalsoft tissues intomaxillary or ethmiod sinus Artophy of orbital fat and scarring within fat #fragments > 2cm squre area / that aredisplaced > 3cm- potential surgical indication 15. Solitary strut ISOLATED ZYGOMATIC ARCH-due to focussedtrauma Non displaced /displaced inward or outward Surgery for cosmetic reasons Inward displacement can impinge coronoidprocees-can limit mandibular motion ISOLATED FRONTAL/MAXILLARY SINUS WALL NASAL FRACTYRES- most common ,50% Comminuted or displaced 16. COMPLEX STRUT# NEO/NASOMAXILLARY 4 facial struts converge in this region-single medialand 2 medial paramedian + superior horizontal Always complex and comminuted Always involve 2 out of 4 struts Involvement of nasal bone +frontal process ofmaxilla-free movement 50% unilateral Fragments displaced posteriorly-cribrifom plate Displaced laterally- NLD,NFD,Ocular injuries 17. COMPLEX STRUT # ZYGOMATICOMAXILLARY COMPLEX-ZMC Zygoma-inferolateral margin of orbit Point of intersection of lateral paramedian ,middlehorizontal 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 18. 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 19. 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 disconnectionbetween facial skeleton and skull base Single most charecteristic feature isinvolvement of pterygoid plates 20. Le Fort type I Horontally oriented invoving inferior portionof maxillary antra , medial wall of maxillarysinus and inferior nasal septum, posteriorlythrough pterygoid plates + # hard palate Palate along with maxillary ridge and alveolusof maxilla- free fragment FLOATINGPALATE Mid face swelling, echymosis/nasopharyngeal bleed 21. 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 ethmiodalcomplx Lateral side wall- medial orbital wall, orbitalfloor, inferolaterally anterior and posterolateralwall of maxillary sinus terminating to pterygoidplates Central pyramid displaced posteriorly- DISHFACE DEFORMITY 22. Le Fort type II-contd No involvement of medial wall of maxillarysinus,inferiornasal septum,hard palate,lateralorbital wall,zygomatic arches Severe cosmetic deformity Malocclusisn Infra orbital nerve injury 23. Lefort type 3 Craniofscial dysjunction Le fort 2 + lateral orbital wall and zygomaticarches SMASH FRACTURES High energy injuries causing severecommunition ,usually associted with IC bleed,temporal bone # and cervical spine injuries 24. MANDIBULAR FRACTURE 50% SOLITRY,50% MULTIPLE SIMPLE-no communication to oral cavity/skin COMPOUND COMMINUTED-multiple fragments IMPACTED-foreshortening + restrictedmovements GREEN STICK- only one side of cortex PATHOLOGIC-underlying osseous disease 25. Mandibular fracture -contd Commonest site- condyle/sub condylar area INTRA CAPSULAR- less common, inchildren,secondary OA changes EXTRACAPSUALR-unilateral> bilateral Unilateral associated with contralateral angle# Rarely force of impact of condyle transmitted totemporal bone carotid canal ICA injury 1 mm axial ,MPR /curved reformats similar toOPG 26. Radiological evaluation andinterpretation 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 singletissue(bone) /multiple tissue(bone ,fat and muscle) 27. IMAGING GOALS SCREEN FOR INJURY- plain film occipitomental153-5 mm sections CT DETECTING AND DIAGNOSING high qualityaxial, MPR including curved reformats DEPICTION OF INJURY-3D surgical planningandPatient education Advances in 3D- volumetric assessments Advanced volume rendering techniqus Virtual surgery 28. MDCT- additional sagital and obliquecoronal- orbital floor/mandibular # Curved reformats- condyle /coronoid orocess NEW HORIZONS INTRA OPERATIVE CT REAL TIME 3D New stabilization /fixation materials nonmetallic and resorbable 29. SURGEONS PERSPESTIVE Ct added a 3rd dimension to the craniofascialtrauma 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,highvelocity Relationship of fracture fragments to critical softtissues like optic nerve/extra ocular muscles Alterd orbital volume 30. 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 31. CONCLUSION Craniofascial trauma remains a prevalentcondition nowadays and typically requiresintense and immediate clinical decision that is largely dependant on radiologicdetection and depiction of injuries Recent advances in spiral CT and computerpost processing technologies made CT toevaluate CFT patients thouroughly andefficiently and become the IMAGINGMODALITY OF CHOICE 32. THANK YOU