dentalaka: Management of facial trauma-Mid-face Injury-Oral and Maxillofacial Surgery

Mid-face

Definition:

The area between a superior plane drawn through the zygomatico-frontal sutures tangential to the base of the skull and inferior plane at the level of the maxillary dental occlussal surface.

Structures connection
(structures in relation)

Orbit
Maxillary sinus
Nasal bone
Naso-orbital ethmoid (NOE) complex
Zygomatic complex
Frontal bone and sinus
Vertical and horizontal pillars

Area of strength

Vertical and horizontal pillars
Muscular attachment

Area of weakness

Sutures
Lining tissues and air-filled cavities

Pattern of fractures of mid-face skeleton

Alveolar fracture and dental fracture
Le Fort ‘s fracture (french surgeon Rane Le Fort 1901)
Naso-orbital ethmoid fracture
Zygomatic complex and arch fracture
Frontal sinus and bone fracture

Alveolar bone fracture

Involve block of alveolar bone with or without

Intrusion of teeth
Extrusion of teeth
Luxation of teeth
Fracture of teeth

Le Fort’s fractures

Le Fort I (low level or Guerian fracture)
Unilateral/ bilateral
Horizontal fracture through the maxilla above the level of the nasasl floor and alveolar process

Piriform rims
Anterior maxilla
Zygomatic buttresses
Ptrygoid laminae

Signs and symptoms

Slight swelling of upper lip
Ecchymosis in upper lip sulcus
Hematoma intra-orally over zygoma and in palate
Disturbed occlusion
Mobility of teeth of the involved segment of maxilla
Combination of soft tissue laceration
Exposure of nares and the maxillary antra in case of gross injury
Impacted type of fracture is oftenly not mobile and teeth cusps may be damaged
Cracked-pot percussion of upper teeth

Le Fort II (pyramidal or subzygomatic)

Separation of NF suture, medial orbital walls (lacrimal bone), inferior orbital floor and rim (adjacent to infrorbital canal and foramen), anterior maxilla below zygomatic buttress and ptrygoid laminae about halfway up.

Separation of the block from the base of skull is completed via the nasal septum and may involve the floor of the anterior cranial fossa

LeFort III (cranifacial dysjunction, high transverse, suprazygomatic)

Separation of NF suture, medial orbital walls (involve the depth of the ethmoid bone and cribriform plate, pass below optic foramen and cross the inferior orbital fissur), inferior orbital floor, lateral orbital wall, ZF suture, zygomatic arch, suprazygomatic to the root of ptrygoid plate.

Signs and symptoms
although it is possible to distinguish between le fort II and III, the signs and symptoms are almost similar

Gross edema of soft tissue
Bilateral circumorbital ecchymosis
Bilateral subconjunctival hemorrahge
Obvious deformity of the nose
Nasal bleeding and obstruction
CSF leak rhinorrhea
Dish-face deformity
Limitation of ocular movement
Possible diplopia and enophthalmous
Retropostioning of the maxilla with anterior open bite
Lengthening of the face
Difficulty in mouth opening
Mobility of the upper jaw
Occusional hematoma of the palate
Cracked-pot sound on percussion
Step deformity at infra-orbiatal margin
Anasthesia of midface
Nasal bone moves with mid-face as a whole
Tenderness and sepration at FZ suture
Tenderness and deformity of zygomatic arch
Depression of occular level and pseudoptosis

Bowerman classification of midface-fracture (1994)

Fracture not involving the occlusion

Central region

Nasal bone/ septum (lateral, anterior injuries)
Frontal process of the maxilla
Nasoethmoid
Fronto-orbito-nasal dislocation

Lateral region (zygomatic complex EX dento alveolar frcature

Fracture involving the occlusion

Dento alveolar
Subzygomatic:

Le Fort’s (I, II)

Supra zygomatic:

Le Fort III

These fractures may occur unilaterally or bilaterally, with separation of maxillary midline and or extension to frontal or temporal bone

Prevalence of mid-face fractures

Diagnosis

Inspection

Extra-oral (e.g. swelling, deformity, asymmetryc Leaks)

Intra-oral (e.g. hematoma, occlusion)

Palpation

Step deformity, criptation, cracked pot sound, mobility
Radiographical investigations

Radiographical examination

Plain radiograph

Occipitomental (10 or 30 degree)

Search line (Campbell’s line 1977)

Water’s view

Suitable for isolated orbital fracture

Lateral skull view

OPG

Occlusal view of the maxilla

Perapical views of damaged teeth

CT scan

3-D CT imaging

Coronal sections

Axial sections

Whenever intracranial damage and frontal sinus are suspected
Extensive fracture that involves nasoethmoid complex or orbital region
Orbital trauma to evaluate the degree of orbital injury and enophthalmos

Indications for treatment

Physical signs of a fracture of the maxilla.
Evidence of a fractured maxilla on imaging.
Disruption of the occlusion of the teeth.
Displacement of the maxilla.
Post traumatic facial deformity.
Indications for treatment
Fractured or displaced teeth.
Cerebrospinal fluid leak.
Abnormal eye movement or restriction of eye movement.
Occlusion of the nasolacrimal duct.
Sensory or motor nerve deficit.
Other evidence of loss of function

Aims of treatment

Relieve pain
Restore function.
Restore bone anatomy.
Prevent infection
Restore the dental occlusion
Restore jaw movement at the earliest possible stage
Restore normal nerve function

Factors affecting the risk

Association with multiple injuries.
Presence of uncontrolled haemorrhage
Impairment of the airway.
Presence of bone comminution
Association with a dural tear.
Association with a base of skull fracture.
Presence of a pre-existing dentofacial deformity.
Time elapsed since the injury.
Presence of a medical or surgical factor which would delay general anesthesia
Presence of any factor which would delay healing. (eg nutritional deficiency or alcoholism)
Stage of dental development (deciduous, mixed or permanent dentition)
Presence of fractured teeth.
Total absence of teeth (edentulous)
Inability of the patient to co-operate with treatment.
Association with fractures of the mandible especially bilateral fractures of the condyles.