CHAPTER 03: MAXILLOFACIAL Flashcards

Question

What are the usual fracture patterns?

Answer 1

1. Simple o # line down from infraorbital foramen. o Displacement usually medial with medial or lateral tilt and impacted. o Infraorbital nerve compressed in canal o Branches of superior dental nerve cross # = numb teeth 2. Comminuted o simple + floor of orbit comminuted and depressed o Herniation of orbital fat (like blow-out #) 3. Zygomatic Arch # o Localised depression of arch o Medial depression → impinge on coronoid process → trismus

Answer 2

Classification of Zygomatico-orbital Fractures 1. Undisplaced 2. Arch # only 3. Tripod # and ZF suture intact 4. Tripod # and ZF suture disruption 5. Pure blowout # 6. Orbital rim # 7. Comminuted and other #

Answer 3

LOOK - swelling and bruising, conjunctival haem, malar flat, enophthalmos FEEL - tenderness, step, # mobility MOVE - trismus, dystopia

Answer 4

1. Swelling and bruising - very variable, external or intraoral - Subconjunctival haemorrhage lateral to limbus = orbital fat bleed 2. Alteration of bony contour - Malar depression Flattening of cheek prominence, step in infraorbital margin at infraorbital foramen 3. Sensory Loss - teeth = sup dental nerve - upper lip and alar = infraorbital n 4. Enophthalmos (look from above) - Reduced orbital fat vol → herniated into antrum → posterior displacement of globe 5. Dystopia - Alteration of position of orbit and its contents. i. Lateral dystopia ii. Vertical dystopia iii. Combination of lateral and vertical 6. Diplopia = double vision - Usually looking up, may be transient caused by entrapment of inferior rectus muscle. Tethering of the orbital contents within the fracture lines can be detected with the forced duction test 7. Decreased visual acuity - ?retinal detachment 8. Trismus + restricted lateral mvmt mandible 9. Epistaxis - tear in mucosal lining of the max sinus

Answer 5

``` Xray - AP, lat 30° OM view (Waters), 60° OM view - Lines of Dolan and Elephants of Rogers Caldwell views - ZF suture Blood in antrum Look for irregularities / fractures near infraorbital foramen, zygomatic arch & lat wall of antrum ``` CT - depressed orbital floor, fat hernation

Answer 6

 ZF Suture  Infraorbital rim  Zyg Arch - may # in 2 places  Buttress

Answer 7

Conservative - stable, undisplaced, review Surgery - numb, trismus, diplopia, enophthalmos, deformity  Isolated infraorbital anaesthesia should be elevated or may get neuralgia  Simple # or arch # = temporal reduction  Comminuted # = direct exposure and fix  Most need plating to avoid recurrence of malar flattening (unstable due to pull of masseter)

Answer 8

``` Ind = pure displaced zygomatic arch # Deep temporal (temporalis) fascia is attached to upper border of zygomatic arch, temporalis muscle runs under. ``` 1. 2cm oblique skin incision over temporalis (radial) – in hair-bearing skin 2. Avoid superficial temporal vessels, go through temporoparietal fascia (superficial temporal fascia) and follow plane until 2cm above zygoma. 3. Incise white superficial layer of deep temporal fascia (temporalis fascia) to sup temp fat pad (frontal nerve above this) 3. slide Bristow elevator in this plane, down behind the arch and then lever outwards – champagne cork snap on reduction. DO NOT pivot elevator on temporal bone.

Answer 9

Ind: if unstable after reduction, comminuted, or other middle 1/3 #

Answer 10

1. Upper lid → temporal process and supraorbital rim 2. Subciliary → sphenoid process (infraorbital rim) and arch 3. Buccal → maxillary process 4. Bicoronal Approach → medial wall of orbit and zygoma

Answer 11

``` Complications Early - Diplopia (usually resolves in 24hrs) - bleeding (retro-orbital haematoma) - nerve injury ``` Late - plate infection, extrusion, migration - scars, - ectropion - union problems - sinus problems

Answer 12

- Often occur in conjunction with zygomatic fractures, nasoethmoid, high le Fort #s - Isolated orbital # from pressure to the globe Orbit fractures at its weakest Adults - the inferomedial floor (lamina papyracea = paper layer) Children - roof (emergency surgery)

Answer 13

1. Bruising, swelling 2. Subconjunctival haematoma with no post limit 3. Palpable steps in orbital margin 4. Enophthalmos - increase volume of orbit, ↓ volume of contents, intraorbital fat atrophy (late) – measured from lateral orbital rim using Hertel’s exophthalmometer 5. Hypoglobus – downward displacement of globe 6. Orbital dystopia – unequal orbit heights 7. Diplopia - Entrapment of fat, fascial attachments or muscles within fracture lines, contusion of recti or oblique muscles. Usually on upward gaze as most # and tethering occur inferiorly. ``` PROPTOSIS = forward displacement of any organ. EXOPHTHALMOS = only applied to eye. (Some it define as proptosis secondary to endocrine causes) EXORBITISM = small orbital cup leading to protruded appearance of contents ```

Answer 14

Site, extent and displacement PA, OM (teardrop sign - fat herniating into maxillary sinus) CT scan 3D CT reconstruction

Answer 15

``` Symptomatic diplopia Significant enophthalmos Radiological evidence of orbital content entrapment Large bony defects Other fractures requiring fixation ```

Answer 16

``` ACCESS Lower eyelid incision - explore and delineate # - release any trapped structures REDUCE fractures RECONSTRUCT orbital floor - Autologous vs alloplastic (see below) ``` Secondary reconstruction is very difficult!

Answer 17

Approaches Cutaneous - subciliary / subtarsal / orbital rim Skin / skin & muscle Transconjunctival +/- lateral canthotomy Pre-septal (avoid fat) vs post septal Medial floor - Bicoronal vs Lynch (incision medial to medial canthus)

Answer 18

Bone - split calvarium, Iliac crest, rib, antral wall, mandible Cartilage - septal, ear, rib Allogenic - banked bone, lyolysed cartilage Alloplastic - resorbable (vicryl mesh) vs non-resorbable (e.g. Medpore, titanium mesh, Gore-Tex, Silicone)

Answer 19

1. Entrapment of CN 3,4, frontal branch of 5, 6, nerve to levator palpebrae superioris 2. Same as SOF + optic nerve CN2

Answer 20

- Trauma to interorbital region - May be associated with other fractures (medial orbit, root of nose, ethmoid air cells) - Bruising and swelling - Palpable bony step - Telecanthus (if medial canthal tendon detached) - Enophthalmos - Diplopia

Answer 21

1. Access : Overlying lacerations, Bicoronal, Medial orbital incision (Lynch) 2. Reduction : Elevate nasal bones, replace anatomically +/- bone grafts to reconstruct dorsum of nose. 3. Fixation : Plates and screws to nasomaxillary buttresses, repair medial canthal tendon (plate / transnasal / bone fixation devices. Lacrimal system not routinely explored

Answer 22

- blow to glabellar area - Bruising, swelling, crepitus - Palpable bony steps - CSF rhinorrhoea - Late signs - sinusitis, mucocoeles and meningitis

Answer 23

Priniciples Anterior table vs Posterior table Anterior table fracture Displaced (op) vs non-displaced (observe) Nasofrontal duct involved? Yes → reduction, stabilisation, obliteration or cranialisation No → reduction, stabilisation Posterior table fractures (usu with ant table) Displaced? no → CSF leak? no → observe Displaced? no → CSF leak? yes → observe 7 days, then dural repair +/- cranialisation Displaced? yes → CSF leak? Y/N → Nasofrontal duct involved → No → reduction & stabilisation of anterior wall Yes → reduction & stabilisation w obliteration / cranialisation

Answer 24

1. Fixation plate / wire, may need calvarial bone graft if comminuted. 2. Obliteration of sinus = complete removal of mucous lining, spontaneous osteogenesis or bone graft. 3. Cranialisation = complete removal of mucous lining, plug the nasofrontal duct with bone graft, remove post wall, allows the brain and dura to advance to fill the defect.

Answer 25

Can have serious consequences - Meningitis - Cerebral abscess - Mucocoeles - Osteitis

Answer 26

- nasal bones - frontal processes of maxilla - nasal cartilages - nasal septum (quadrilateral cartilage, perpendicular plate of ethmoid, vomer)

Answer 27

Lateral force - nasal bones, septum, lateral deviation of entire nasal complex Head on force - backward displacement and splaying of nasal bones → saddle deformity - septal buckling / fracture +/- septal haematoma (must examine) Nose = most common facial fracture 80% fractures occur at junction of thick & thin parts parasthesia of nasal tip = anterior ethmoidal nerve injury

Answer 28

1. Anterior ethmoidal 2. Posterior ethmoidal (both opththalmic) 3. Sphenopalatine (maxillary) 4. Greater palatine (maxillary) 5. Branch of superior labial (facial)

Answer 29

- Nasal swelling and bruising - Haematoma extends from nose into the periorbital area - Respiratory obstruction - Epistaxis - Change of bridge contour - Nasal bridge skin, mucosal lacerations - New asymmetry - Septal injury, look for haematoma - Untreated haematoma can lead to pressure necrosis of nasal septum

Answer 30

Xrays not always necessary - treat on clinical grounds OM 45° view CT if complex

Answer 31

Stranc and Robertson, Annals Plast Surg 1979 Lateral Impact Plane 1 o Unilateral displacement of one nasal bone into the nasal cavity. Plane 2 o Moderate medial (internal) displacement of ipsilateral nasal bone with some outward displacement of contralateral nasal bone Plane 3 o Involve the frontal process of the maxilla at the piriform aperture on one side and are hemi-nasoethmoidal-orbital fractures Frontal Impact Plane 1 o Involve the distal ends of nasal bones, usually bilateral but worst on one side. o Frontal impact nasal fractures involving anterior portion of nasal pyramid and septum. o Disruption of cartilaginous septum Plane 2 o Displace at least the lower half of both nasal bones and accompanied by some telescoping of septum. Almost always reduction in nasal height, with the bone decrease usually less than the height decrease of the cartilaginous septum. Clinically → dorsal nasal hump. o More comminution of the nasal pyramid and more dislocation of the septum o Disruption of the bony septum and nasal bones Type III (Plane 3) o Involve frontal processes of maxilla = naso-orbitoethmoidal # o Injuries extend beyond the nasal skeleton into piriform aperture and medial orbital rim o Represent mild nasoethmoidal fractures.

Answer 32

Appearance and function dictate Rx Best to operate 5-7 days after swelling minimised (2 weeks = too set) Assess for deviation or collapse of nasal bones

Answer 33

Early vs Late Presentation Early: Deviation vs Collapse Deviation - thumb pressure (reduce nasal bone that has been pushed out) - Walsham's nasal forceps (to reduce depressed side) - (use corrected sided forceps, rubber sleeve = skin side) - disimpact with side - side mvmt Collapse - nasal bone & septum injury - Walsham's septal forceps (Asch forceps) to straighten septum - evacuate haematoma, quilt septum - pack nostrils, nasal splint - remove pack 48hrs, splint 1wk Late presentation - Open vs Closed reduction - wait until inflammation settled before formal rhinoplasty

Answer 34

Vertical 1. Nasomaxillary buttress - b/t cheek & nose 2. Zygomatico-maxillary buttress - through body of zygoma up into lateral orbital rim and zygomatic arch 3. Pterygopalatine buttress which passes posteriorly Horizontal 1. Zygoma 2. Infra-orbital rim 3. The alveolar arch

Answer 35

line passes transversely across 1. base of piriform aperture 2. base of maxillary sinus 3. pterygoid plates Pattern divides the maxilla into 2 segments. Lower segment = floating palate  contains the alveolus, the palate and the pterygoid plates. - horizontal fracture that separates alveolar and palatine processes from the body of the maxilla

Answer 36

aka pyramidal # # line passes 1. across nasal bones 2. Into medial wall of orbit 3. Diagonally downwards and outwards through maxilla 4. Through pterygoid plates The bony fragment contains: lacrimal crests, bulk of maxilla, piriform margin, alveolus and palate.

Answer 37

aka craniofacial dysjunction # line passes 1. through nasofrontal suture 2. across orbital floor to ZF suture 3. through zygomatic arch and pterygoid plates. This results in detachment of entire midfacial skeleton from cranial base. Sagittal # of maxilla and isolated # of alveolus may also occur

Answer 38

``` Bruising, swelling, Battle's sign Malocclusion Epistaxis Enophthalmos Diplopia Infraorbital nerve sensation ↓ Palpable step in bone / dentition Dish face deformity Mobile maxillary segment (stabilise glabella & distract alveolus) ``` 1. Alveolus alone = Le Fort I 2. Alveolus and nasofrontal = Le Fort II 3. Alveolus, nasofrontal region and ZF suture = Le Fort III.

Answer 39

``` Identify site, extent and displacement. PA Waters = OM - shows # lines and fluid in sinus. CT scan 3D CT reconstruction ```

Answer 40

ORIF Incisions - bicoronal (nasofrontal, orbital walls, ZF suture, zygomatic arch) - lower eyelid (orbital floor, infraorbital rim) - upper buccal sulcus (lower maxilla) Reduction - Rowes distraction forceps / Tessier disimpaction forceps - stabilised with IMF Fixation - temporary intermaxillary fixation - interosseous wires - mini plates & screws (1.5 - 2mm) (across maxillary buttresses) - bone grafts - external fixation

Answer 41

2nd most common facial fracture ``` Location - usually >1 fracture e.g. condyle + parasymphyseal / angle  Condyles 36%  Angle 20%  Body 20%  Symphysis 14%  Alveolus 4%  Ramus 3%  Coronoid Process 3% ``` Open fracture into mouth - cover w antibiotics young - fight injuries 97%, elderly - falls

Answer 42

Airway obstruction Pain Swelling Trismus Malocclusion Crepitus Bruising → extra or intraoral (sublingual) Palpable step → mandibular border/ dentition Paraesthesia → inf alveolar / mental nerve Chin deviated → side of fractured condyle

Answer 43

Closed / compound (skin, buccal mucosa, tooth socket) Anatomical location Displacement Comminution

Answer 44

Parasymphyseal fragment is pulled - down by geniohyoids - down and lat by digastrics - back by genioglossus. Body of mandible is pulled - up by masseter - up and back by temporalis - back by pterygoids

Answer 45

Unfavourable o fracture line slopes upwards and anterior from the lower border of the mandible, o or slopes anterior and inwards in the transverse plane. o inherently unstable because of the pull of the masseter, digastric and pterygoids (distracts the fragments)

Answer 46

``` OPG PA view - condyles Lateral oblique reverse Townes - condyles CT scan of little value if no other fractures ```

Answer 47

Conservative o Most Condylar fractures o Stable undisplaced fractures, normal occlusion o Minimal trismus ``` ORIF o Malocclusion o Pain that doesn’t settle o Mobile # fragments o Multiple # fragments o May get paraesthesia after surgery - NOT indication for ORIF ```

Answer 48

``` Consent - Numbness made worse, infection, plate problems GA Nasal Tube Throat pack Antibiotics Not muscle relaxed (more wobbly) Dexamethasone 8 mg single dose ```

Answer 49

Intraoral approach - Mucoperiosteal flap, protect mental nerve Submandibular approach - for difficult fractures Retromandibular approach (below ear) Preauricular approach (esp TMJ)

Answer 50

``` Erich arch bars Bridle wire Ivy loops, Temporary IMF Senior assistant to hold Temporary IO wire ```

Answer 51

Miniplates and screws - Unicortical (not bicortical) to save the teeth roots Can be 'load-bearing' or 'load-sharing' constructs Load-bearing - rigid plate bears forces of function at fracture site - atrophic, edentuous, comminuted fractures Load sharing - lag screw / compression plating / mini-plate - single fracture, good bone stock External fixation - rarely used

Answer 52

Options 1. conservative 2. Elastic IMF for traction to correct lateral open bite 3. ORIF - indicated if → condylar head dislocated from the TMJ → condyle lateral displaced 30deg or more from the axis of the ascending ramus → in bilat # assoc w shortening of ascending ramus and open bite → Can’t get adequate occlusion with closed reduction → foreign body in TMJ (eg bullet) → poor compliance

Answer 53

Transparotid approach - condyle access Risdon + preauricular incsion - high ramus fracture Incise down to parotid capsule, then blunt dissection through gland (preserve CN VII) Plate TMJ dislocation - reduce by downward and backward pressure by thumbs placed on the posterior molar teeth under GA

Answer 54

Vertical buttresses 1. Nasomaxillary - alveolar process of maxilla (Canine) to frontal process of maxilla and nasal bones (i.e. medial to orbit) 2. Zygomaticomaxillary - alveolar process of maxilla (opp 1st molar)to zygotic process of frontal bone (i.e. lat to orbit) 3. Pterygomaxillary - post body of maxilla via sphenoid to skull base (including pterygoid plates) 4. Mandibular - ascending ramus to skull via TMJ ``` Horizontal 1 Supraorbital bar 2 Infraorbital rim 3 Zygomatic arch 4 Maxillary (palate) 5 Mandibular (body of) ```

Answer 55

Alveolar - becomes resorbed in edentulous pts Frontal - supports nasal bones Zygomatic - articulates with zygoma Palatine - articulates with vertical / horizontal plates of palatine bone

Answer 56

External Trigeminal nerve V1 - infratrochlear, external nasal nerves V2 - infraorbital, anterior superior alveolar nerves Internal Trigeminal nerve anterior ethmoidal (direct continuation of nasociliary nerve), infraorbital, posterior superior alveolar nerves posterior superior nasal, greater palatine and nasopalatine nerves (via pterygopalatine ganglion)