os - trauma Flashcards
symptoms of # zygoma
- ocular symptoms due to proximity of zygoma to orbital floor
- maxillary sinus fills with blood so epistaxis as max sinus drains through nose via semi lunar hiatus
supply of eye muscles
CN VIII oculomotor
except
LR7 - lateral rectus CN VII
SO4 - superior oblique CN IV trochlear
clinical symptoms of zygomatico-orbital trauma (8)
- step deformity
- epistaxis - unilateral
- periorbital bruising & swelling
- subconjunctival ecchymoses
- sensory defect via infraorbital nerve i.e. numbness in the cheek
- diplopia
- subcutaneous emphysema
- flatness of the face
inital mx of ZO #
- exclude ocular injury - warn signs re retrobulbar haemorrhage
- prophylactic ABs
- avoid nose blowing
definitive mx of ZO #
- r/v when swelling subsided
- CBCT / occipitomental 15 & 30 degree views
- informed consent
- closed reduction +/- fixation
- OR +/- IF
muscles that close mandible
masseter
medial pterygoid
temporalis
muscles that open mandible
anterior belly digastric
mylohyoid
geniohyoid
damage to IAN manifests as
numbness of lower lip & chin
causes of numbness to IAN (4)
- direct trauma
- impacted M3M
- infection of bone i.e. osteomyelitis
- resorption of bone due to pathology i.e. cyst
signs & symptoms of mandibular #
pain, swelling, loose / mobile teeth, deviation of mandible to opp side of #, facial asymmetry, AOB (# can cause shortened ramus), numbness of lip, bleeding limited to # site
important to look at FoM for sublingual haematoma
to classify mandibular # (5)
- involvement of surrounding tissue i.e. simple / compound / comminuted
- no of # i.e. single / multiple
- site of # lines i.e. uni / bi / multi
- direction of # line i.e. favourable / unfavourable
- if displaced or undisplaced
involvement of surrounding tissue
- simple = everything intact
- compound = soft tissue damaged thus exposing # to environment
- comminuted = bone broken into may small pieces
what causes displacement of #
1 group of muscles will pull the segment up and the other group of muscles will pull the segment down therefore causing displacement
direction of # line
favourable - minimises displacement
unfavourable - encourages further displacement
causes of # displacement (6)
- magnitude of force
- mechanism of injury
- other associated #s
- opposing occlusion; if v good displacement minimal as acts as stopper
- direction of # line
- if soft tissues intact# unlikely to be displaced
pathological causes of # (3)
expanding cystic lesions
osteoporosis
osteomyelitis
greenstick #
in children where bone is softer due to organic content so bends rather than breaks
mx of mandibular #
- clinical exam
- radiographs i.e. OPT & PA // CBCT
- control pain & infection i.e. compound requires ABs
- undisplaced potentially no tx but displaced requires tx
any # in tooth bearing area
is a COMPOUND #
why ? direct communication with pd which is in communication with oral cavity
only not the case in edentulous pt
to identify # on radiograph (3)
- radiolucent line
- loss / deformity of medial border of mandible
- step in occlusion
2 main methods of tx for any #
- reduction = putting segment back into correct position
- fixation = if displaced it MUST be reduced and fixed
closed reduction & fixation
no cutting or raising of flaps, do not open #, depends on pt occlusion to guide process
uses intramaxillary fixation to assume if teeth are re placed in correct position then mandible must be in correct position
involves wiring jaw shut for 6wks
CR & intermaxillary fixation contraindicated in pts with
epilepsy
open reduction & internal fixation
expose bony edges surgically i.e. raise flap and reduce directly with vision then fixed with plates & screws
indications for ORIF of condylar #
- bilateral subcondylar # with AOB
- displaced # middle cranial fossa
- displaced # causing occlusal derangement
- displaced condylar # causing limited mouth opening
- displaced # causing ramus shortening
le fort I
line passes through alveolar ridge / lateral nose / inferior wall of maxillary sinus
horizontal maxillary # separating teeth from upper face
MAXILLA ONLY
le fort II
pyramidal # with teeth at base & nasofrontal suture at apex
inferior orbital rim = type II; if not then excludes this
MAXILLA & NOSE
le fort III
zygomatic arch involved = type III if not then excludes this type
risk to temporalis
MAXILLA, NASAL BONE, ZYGOMA
any combination of le fort
is possible
# of pterygoid plates is mandatory to diagnose le fort
basic principles of distraction osteogenesis (5)
- osteotomy (location & direction)
- latency
- remodelling
- consolidation
- distraction (vector / rate / rhythm - want 1mm / day)
where you get bone for graft from
chin / ramus / hip (iliac ridge)
signs of retrobulbar haemorrhage
pain
proptosis
blurred vision
tx lateral canthotomy to decrease pressure behind eye
initial mx of zygomatico orbital #
conservative
exclude ocular injury
antibiotic prophylaxis
nose blow instructions / anything that creates pressure i.e. same as OAC
r/v after 7-10 days to allow for reduction in swelling
