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Maxillofacial

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Maxillofacial injury

Causes

Fractures

Soft tissue injuries

Complications

Associated injuries

Management

Penetrating injury

Causes

- while direct cause is trauma it is important to consider possible cause of trauma eg alcohol leading to RTA; epilepsy, cardiac disease or hypoglycaemia leading to LOC

Fractures

- most common fractures of facial bones:

  • nasal bones (32-45%)
  • zygoma and zygomatic arch (13-15%)
  • mandible (10-13%)
  • orbital floor (3%)
  • maxilla (2-10%)

Mandibular fractures

- common sites are ramus and body at level of 1st or 2nd molar regardless of site of impact
- multiple fractures are common
- fractures of body often associated with fractures of opposite angle or neck
- mandibular fragments are often distracted due to action of lower jaw muscles and thus tongue may be displaced posteriorly following bilateral angle or body fractures leading to airway obstruction

Midface fractures

- usually associated with other fractures
- LeFort classification:

I. Dentoalveolar # which follows a horizontal plane above floor of nose. Separates palate from remainder of facial skeleton
II. Lower nasal bridge through medial wall of orbit and across zygomatico-maxillary process. Most common midface #. Results in a freely mobile pyramidal-shaped portion of maxilla
III. Runs parallel to base of skull. Separates midfacial skeleton from base of skull. Upper nasal bridge, through most of orbit and across zygomatic arch. Involves ethmoid bone and may transect cribiform plate at base of skull

- rarely occur in pure form and most are mixed (eg LeFort II on one side and III on other)
- basal of skull # frequently associated with LeFort III and occasionally LeFort II

Fractures of zygoma and orbit

- zygoma fractures uncommon but its attachments to maxilla, frontal and temporal bones are vulnerable and may be disrupted
- displacement of zygoma may result in disruption of lateral wall and floor of orbit
- orbital blow-out fractures occur when pressure is directly applied to eye and is hydraulically transmitted via globe to interior bony structures. Inferior wall usually fractures. Causes enophthalmos, impaired eye movement and infraorbital hypoasthesia

Nasal fractures

- diagnosis is largely clinical
- major concerns are epistaxis and septal haematoma
- more complicated nasoethmoid fracture caused by trauma to nasal bridge may cause persistent epistaxis and CSF rhinorrhoea. CT scan and neurosurgical opinion.

Soft tissue injuries

- injuries to cheek between tragus of ear and vertical mid-pupillary line should raise suspicion of facial nerve, parotid gland or duct injury

Complications

- tend to be more devastating than injury itself

Airway obstruction

Can develop by several mechanisms:

  • posteriorly displaced distal fragment of a parasymphyseal mandibular # allows floor of mouth to fall backwards
  • in bilateral double fractures of body, free mandibular segment may be pulled medially by effect of mylohyoid, pushing tongue up to palate and thus obstructing airway
  • swelling of tongue, palate, pharynx, floor of mouth secondary to oedema or haematoma
  • # of pterygoid plate in association with midface # allow posterior shift of whole midface resulting in narrowing of nasopharynx. Not an immediate problem if patient is conscious as simply results in mouth breathing but may result in severe airway obstruction in unconscious patient
  • foreign bodies, blood, teeth, dentures

Haemorrhage

- common. Nose and tongue are main sources
- severe bleeding usualy involves a lingual, internal maxillary, anterior ethmoid or posterior ethmoid artery
- Le Fort and nasoethmoid fractures result in most profuse bleeding
- although at times bleeding from facial fractures is serious and life threatening it is usually minor and rarely cause of severe hypovolaemia. Thus presence of hypotension in patient with facial injuries should trigger a search for other causes
- massive bleeding from facial injury may go unnoticed, especially in patients with impaired consciousness, because blood is swallowed
- risk of aspiration of blood either directly or in association with regurgitation or vomiting

CSF rhinorrhea and otorrhea

- usually due to base of skull #
- associated with risk of meningitis, brain abscess and encephalitis
- treat with broad spectrum antibiotics

Surgical emphysema and pneumomediastinum

Picture

- uncommon
- air from maxillary and ethmoid sinuses can communicate with fascial planes of neck and thence with mediastinum
- pneumomediastinum is a benign complication of facial fractures but may also be caused by injury to larynx, trachea, lungs or oesophagus. These should be excluded before assuming that it is a result of facial #

Infection

- in addition to CNS infection, infection in vicinity of # sites, extension into fascial planes of face and neck and spread to distant sites can occur
- delay of definitive surgical treatment does not increase infection rate
- extension of infection into fascial planes may jeopardize airway. Organisms are typically both anaerobic and aerobic. Treatment consists of IV penicllin and drainage. Preoperative CT of face and neck should be performed to assess severity of airway obstruction and if severe tracheostomy under local anaesthesia is indicated. If moderate perform awake fibreoptic intubation with facilities at hand for emergency tracheostomy

Death

- seldom life-threatening in absence of associated injuries
- hypoxia is principal cause of death. Suggested that this is usually due to a combination of head injury and massive blood aspiration rather than airway obstruction from displaced jaw fractures

Associated injuries

- common
- head injury 15-48%. More common after RTA
- cervical spine injury. Lower facial injuries tend to be associated with C1 and C2 injuries while middle and upper facial injuries associated with lower cervical spine injuries. Spinal canal of upper cervical vertebrae wide in relation to spinal cord and so neurological injury more common with lower cervical injury
- eye injuries: usually minor and do not require specialized anaesthetic management
- thoracoabdominal injuries in 5-15%
- limbs

Management

NB most maxillofacial injuries can wait up to 6 days without deleterious effects on outcome of repair provided that soft tissue injuries are treated and intermaxillar fixation is applied. This can be performed under local anaesthesia

Initial management

- airway management principal task
- 2-6% require emergency intubation to relieve airway obstruction, improve oxygenation or initiate hyperventilation for associated head injury
- even an unobstructed airway should be carefully monitored. Increasing oedema, swelling and haematoma may later compromise airway
- signs of partial obstruction include restlessness, throat clutching, noisy respiration or stridor. Complete obstruction may suddenly develop.
- respiratory distress most commonly due to airway obstruction, pneumothorax, pulmonary contusion, pulmonary aspiration or a combination. Important to make diagnosis as treatment is different for different causes
- most conscious patients with maxillofacial injury breathe more comfortably in a sitting position with body flexed
- if airway obstruction simply due to soft tissue tone anterior traction on tongue or jaw or insertion of oral or nasal airway may be sufficient. Nasal airway must not be inserted if there is a risk of a nasal or base of skull #
- if obstruction caused by a displaced mandibular # anterior traction using a towel clip or wire passed through mandible or tongue will be useful. Chin lift and jaw thrust may also be effective
- examine for and remove foreign bodies, blood and vomitus from mouth and oropharynx
- obstruction may be due to posterior displacement of entire midface. This can be confirmed by palpating pterygoid plate immediately posterior and medial to last upper molar when crepitus will be felt. In these cases palate can be moved anteriorly with fingers thus repositioning entire maxilla and relieving obstruction
- above manoeuvres are only temporary measures and in some patients may not be successful, necessitating emergency intubation or tracheostomy
- 2 types of # cause mechanical limitation of mouth opening: #s through or near temperomandibular joint and #s of zygomatic arch with associated injury to temporalis. In case of latter obstruction is always mechanical whereas with former limitation is due to spasm of muscles surrounding joint. This spasm can be relieved by injection of a few mls of lignocaine 1-2% or bupivicaine 0.5% into mandibular notch
- because of widely differing clinical presentations no single method of definitive airway control can be recommended for these patients. However certain principles need to be followed:

  • irretrievable steps such as use of muscle relaxants or large doses of narcotic should be avoided before intubation unless likelihood of easy intubation is high
  • blind nasal intubation contraindicated in presence of nasal fractures or fractures of base of skull
  • insertion of NG tubes via nose also contraindicated. If, however, a NG tube is passed into cranium it should not be withdrawn as a knot formed during withdrawal may scrape brain tissue and magnify injury. It should, instead be removed surgically
  • possibility of cervical # must be borne in mind and should be excluded if possible prior to airway manipulation
  • always be prepared for emergency cricothyroidotomy. Laryngeal injury, especially cricotracheal separation, relative contraindication. Temporary measure which should be converted to more definitive airway control (eg tracheostomy) once acute hypoxia is relieved
  • fibreoptic bronchoscopy may be ineffective during acute stage of trauma because of poor visualization resulting from blood in pharynx
  • retrograde intubation may be possible if patient is able to open mouth sufficiently to retrieve wire/catheter. However pharyngeal blood may prevent visualization of wire/catheter. Continuous suctioning of pharynx or injection of air through cathter to create bubbles in blood may facilitate location of wire/catheter. Major difficulty during translaryngeal-guided intubation arises during introduction of ETT as it may become caught on anterior commissure of larynx. May be facilitated by passing ETT over fibreoptic bronchoscope and then passing bronchoscope over guide wire

- control of haemorrhage. Occasionally haemorrhage is massive and difficult to control. Once airway secured topical vasoconstrictors, anterior nasopharyngeal packs and Foley catheter balloon filled wth air, placed in posterior nasopharynx, should reduce blood loss. Operative reduction of fractures and direct ligarion of bleeding vessels is undertaken when simple measures fail

Definitive management

- patients without airway obstruction: nurse 30° head-up to drain blood saliva and CSF away from airway
- obstruction of ETT by blood clots not uncommon and airway pressure should be carefully monitored.
- delay definitive surgery until gross facial swelling reduced
- measures to decrease swelling: irrigation and debridement of open wounds, removal of foreign bodies, closure of facial lacerations (within 24 h), head-up position and ice packs
- early surgery preferred for orbital injuries when ocular function is at risk and some other cases

Post-operative

- extubate awake after assessing soft tissue swelling and laryngeal reflexes return. If in doubt leave ETT in place
- dexamethasone 4-8 mg IV may help to reduce oedema
- if intermaxillar fixation is applied keep wire cutter by patient's bed in case of airway obstruction. Only 2 of 4 wires need to be cut. These should be clearly identified
- regular anti-emetic

Penetrating injury

Zones

  1. Area of neck below cricoid cartilage
  2. Area between angle of mandible and cricoid
  3. Area above angle of mandible

Investigations

Arteriography indicated in patients with penetrating trauma to zones 1 and 3 because vascular injury cannot be excluded by clinical examination alone. While in cases with injury in zone 2 arteriography is unlikely to yield positive results in absence of clinical evidence of vascular injury. Vascular injury includes intimal tears, intramural haematoma, pseudoaneurysm, occlusion, A-V fistula and active haemorrhage


© Charles Gomersall September 1999


©Charles Gomersall, April, 2014 unless otherwise stated. The author, editor and The Chinese University of Hong Kong take no responsibility for any adverse event resulting from the use of this webpage.
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