Approaches to the Midface

Author Credentials 

Matthew Mifsud, MD
Clinical Fellow
Department of Otolaryngology-Head & Neck Surgery
University of Toronto
Toronto, ON, Canada
Mifsud.Matthew@gmail.com

Module Summary

The midface is a complex anatomical region, with a bony skeletal framework that is composed of a series of vertical and horizontal buttresses. These represent areas of bony thickening which provide a supportive framework for this region. Consequently fractures which involve the buttresses system can destabilize the midface with both functional and aesthetic consequences. As discussed, appropriate management of midfacial trauma requires the utilization of CT imaging, to adequately classify the injury. This outline details a variety of different surgical approaches can be utilized either alone or in combination, to expose different regions of the midfacial skeleton, to facilitate rigid fixation when required.

Module Learning Objectives 
  1. Describe the anatomy of the midfacial skeleton and understand the importance of the vertical/horizontal buttresses.
  2. Be able to utilize clinical examination and CT imaging to accurately classify aterns of midfacial trauma.
  3. Understand the different surgical approaches to the midface, and when each approach would be utilized.
  4. Be familiar with the complications associated with the surgical management of midfacial trauma.

Embryology

Learning Objectives 

Consider the basic mechanisms of facial growth and how this may be impacted by traumatic injury in the pediatric population.

References 
  1. PMID: 7572089 Tinlader B: Basic mechanisms in craniofacial growth. Acta Odontol Scand. 1995;53(3):144-151.
  2. PMID: 21055606 Aizenbud D, Morrill LE, Schendel SA: Midfacial trauma and facial growth: a longitudinal case study of monozygotic twins. Am J Orthod Dentofacial Orthop. 2010;138(5):641-648.

Anatomy

Learning Objectives 
  1. Consider principles of facial relaxed skin tension lines (RSTLs) and localization of key neurovascular structures in order optimize placement of surgical incisions.
  2. Describe the osteology of the maxillofacial skeleton.
    1. Nasal bones
    2. Zygomatic (malar) bones
    3. Maxilla
    4. Zygomatic processes of temporal bones
    5. Frontal bone
    6. Sphenoid bone
    7. Ethmoid/palatine bones
  3. Understand how these separate units of the maxillofacial skeleton interact with each other to form a series of supportive facial buttresses.
    1. Vertical buttresses:
      1. Nasomaxillary
      2. Zygomaticomaxillary
      3. Pterygomaxillary
    2. Horzintal buttresses:
      1. Frontal bar
      2. Inferior orbital rim
      3. Hard palate
References 
  1. Baker SR. Local flaps in facial reconstruction. 3rd ed. Philidelphia: Elsevier; 2014. p. 71-107.
  2. PMID: 14511857 Linnau KF, Stanley RB, Hallam DK, Gross JA, Mann FA: Imaging of high-energy midfacial trauma: what the surgeon needs to know. Eur J Radiol. 2003;48(1):17-32.
  3. PMID: 23730074 Pappachan B, Alexander M. Biomechanics of cranio-maxillofacial trauma. J Maxillofac Oral Surg. 2012;11(2):224-230.

Pathogenesis

Learning Objectives 

Understand the basic biomechanics of the midfacial skeleton, to understand how different forces applied to the face in particular trajectories can be associated with characteristic patterns of injury/fracture.

References 
  1. PMID: 23730074 Pappachan B, Alexander M. Biomechanics of cranio-maxillofacial trauma. J Maxillofac Oral Surg. 2012;11(2):224-230.

Incidence

Learning Objectives 
  1. Review the most common causes of maxillofacial trauma
  2. Consider the typical age and gender distribution of these injuries
  3. Recognize patterns other potentially life threatening injuries (e.g. intracranial or cervical spine) which are often present in patients with craniomaxillofacial trauma.
References 
  1. PMID: 25139950 Sethi RK, Kozin ED, Fagenholz PJ, Lee DJ, Shrime MG, Gray ST: Epidemiologic survey of head and neck injuries and trauma in the United States. Otolaryngol Head Neck Surg. 2014;151(5):776-784
  2. PMID: 19337097 Mithani SK, St-Hilaire H, Brooke BS, Smith IM, Bluebond-Langner R, Rodriguez ED: Predictable patterns of intracranial and cervical spine injury in craniomaxillofacial trauma: analysis of 4786 patients. Plast Reconstr Surg. 2009;123(4):1293-12301.

Patient Evaluation

Learning Objectives 
  1. Initial evaluation should follow standard ATLS protocol with particular attention paid to airway assessment and initial management of significant acute bleeding (e.g. epistaxis).
  2. Systematic head and neck evaluation is then essential.
    1. Inspection and cleaning of soft tissue injuries.
    2. Palpation for obvious bony defects or step offs.
    3. Assess stability of midfacial segments.
    4. Evaluate dental occlusion and mouth opening/closure
    5. Neurologic evaluation including sensory and facial nerve exam
    6. Orbital evaluation
      1. Note intercanthal distance
      2. Gross assessment of eye position
      3. Check extraocular range of motion
      4. Inspect pupillary function
      5. Assess visual acuity (in awake patients)
References 
  1. PMID 24183371 Krishnan DG: Systematic assessment of the patient with facial trauma. Oral Maxillofac Surg Clin North Am. 2013;25(4)537-44.

Imaging

Learning Objectives 

Understand the role of CT imaging in the diagnosis of midface trauma. Must be able to utilize CT imaging to appropriately classify the pattern of injury.

  1. Naso-orbito-ethmoid (NOE) fracture:
    1. Markowitz and Manson classification (types I – III)
      1. Comment on degree of comminution
      2. Assess fracture pattern in lacrimal fossa (medial canthal region)
    2. Note potential impact on nasofrontal duct
  2. Zygomaticomaxillary complex (ZMC) fracture:
    1. Note presence of and degree of displacement
    2. Describe which aspects of the “quadripod” are affected
      1. Zygomaticomaxillary suture
      2. Zygomaticotemporal suture
      3. Zygomaticofrontal suture
      4. Zygomaticosphenoid suture
    3. Comment on degree of orbital color involvement
  3. Orbital fractures:
    1. Generally medial wall and orbital floor involved.
      1. Comment on percentage of bony wall involved
      2. Compare orbital volume to normal orbit if possible.
    2. Assess inferior rectus (rule out entrapment)
    3. Identify orbital apex (and potential optic nerve) involvement
  4. Le Fort fractures: Remember that classic “Le Fort” fractures imply a particularly unstable injury, with multiple vertical buttresses involved and disruption of posterior maxilla from pterygoid plates. Be able to classify based on location of injury and midfacial buttresses involved.
    1. Le Fort I (lower central midface fracture)
    2. Le Fort II (Intermediate central midface fracture)
    3. Le Fort III (Upper central midface fracture)
References 
  1. PMID 27348349 Nastri AL, Gurney B: Current concepts in midface fracture management. Curr Opin Otolaryngol Head Neck Surg. 2016;24(4):368-375.
  2. PMID 25489392 Cornelius CP, Audige L, Kunz C, Buitrago-Tellez CH, Rudderman R, Prein J: The comprehensive AOCMF classification system: midface fracures-level 3 tutorial. Craniomaxillofac Trauma Reonstr. 2014;7(Suppl 1):S068-S091.

Treatment

Learning Objectives 
  1. Non-operative management:
    1. Maintenance of a stable midface
    2. Non-displaced fracture segments, maintaining appropriate midfacial
    3. No significant change in orbital volume
    4. Normal dental occlusion and absence of trismus
  2. Closed reduction:
  3. Open reduction and internal fixation:

Pharmacology

Learning Objectives 

Consider the appropriate application of antibiotic therapy for both the nonoperative and operative management of midfacial trauma.

References 
  1. PMID 25709755 Mundinger GS, Borsuk DE, Okah Z, Christy MR, Bojovic B, Dorafshar AH, Rodriguez ED: Antibiotics and facial fractures: evidence-based recommendations compared with experience-based practice. Craniomaxillofac Trauma Reconstr. 2015;8(1):64-78.

Surgical Therapies

Learning Objectives 
  1. Review approaches for closed reduction of midfacial (particularly zygomatic arch) fractures
    1. Temporal (Gilles) approach
    2. Transoral (Keen) approach
  2. Consider the different surgical approaches both historical and in common use, that can facilitate access to the midfacial skeleton to facilitate open reduction/internal fixation of fracture segments.
    1. Standard transcutaneous approaches:
      1. Coronal/hemicoronal incisions
      2. Glabellar incision
      3. Supraorbital (superolateral orbital rim) incisions
      4. Upper eyelid blepharoplasty incision
      5. Lower eyelid incisions
        1. Supracilliary incision
        2. Subtarsal (mid-lid) incision – now considered the favored transcutaneous eyelid approach, given improved aesthetic result and decreased risk of lower lid malposition.
        3. Infraorbital incision
    2. Transconjunctival approaches:
      1. Transconjunctival incision: This is used alone generally to approach isolated orbital floor defects.
        1. Preseptal approach
        2. Postseptal approach
      2. Transcaruncular extension: The edition of a transcaruncular incision affords wide exposure to the medial orbit.
      3. Lateral canthotomy: The edition of a lateral canthotomy affords comprehensive exposure to the orbital floor and lateral orbit.
    3. Nasal/endoscopic approaches:
      1. External (open) rhinoplasty approach
      2. Endonasal (closed) rhinoplasty approach
      3. Transmaxillary (via maxillary antrostomy) endoscopic approach
      4. Transantrial (via Caldwell luc) endoscopic assisted approach
    4. Transoral approaches:
      1. Sublabial incision
      2. Midfacial degloving approach
References 
  1. PMID 24979368 Villwock JA, Suryadevera AC: Update on approaches to the craniomaxillofacial skeleton. Curr Opin Otolaryngol Head Neck Surg. 2014;22(4):326-331.
  2. PMID 21659880 Martou G, Antonyshyn OM: Advances in surgical approaches to the upper facial skeleton. Curr Opin Otolaryngol Head Neck Surg. 2011;19(4):242-247.
  3. Ellis E, Zide MF. Surgical approaches to the facial skeleton. Local flaps in facial reconstruction. 2nd ed. Philadelphia: Lippincott Williams & Wilkins; 2006.

Case Studies

  1. A 21 year old male sustains an isolated orbital floor fracture after a physical altercation. >50% of the orbital floor surface area is involved with obvious globe malposition due to increased orbital volume.
    1. Open management would be appropriate.
    2. Access could be obtained either through a transconjunctival or subtarsal approach.
  2. A 25 year old male presents after a motor vehicle accident. There is no evidence of significant intracranial injury but bilateral NOE fracture is present. On the right side a single mobile fracture segment is observed (Markowitz class I) while on the left side there is severe comminution in the medial canthal region (Markowitz class III).
    1. Open reduction and fixation will be necessary
    2. It will be essential, particularly on the left side, to reconstruct the medial canthal tendon attachment.
    3. Generally a bicoronal incision will be necessary to achieve adequate exposure for these injuries.
  3. A 19 year old female presents after an accident where she is kicked in the face by a horse. Imaging and examination reveal a grossly displaced zygomaticomaxillary complex fracture in a pattern consistent with the classically described “tetrapod” fracture.
    1. Will require open reduction/internal fixation with 2-3 points of rigid fixation.
    2. A combination of multiple approaches can be used to visualize different fracture components.
      1. Lower eyelid incision: To expose the orbital floor and inferior orbital rim with a lateral canthotomy added in order to expose the entire lateral orbital region.
      2. Supraorbital or upper eyelid blepharoplasty incision: These approaches will provide the most direct exposure for fixation at the zygomaticofrontal suture line.
      3. Sublabial incision: This provides exposure to the zygomaticomaxillary suture.
      4. Coronal/hemicoronal approach: May become necessary for fractures with severe lateral displacement or comminution of the zygomatic arch requiring fixation for stability.
References 
  1. PMID 24138736 Kochhar A, Byrne PJ: Surgical management of complex midfacial fractures. Otolaryngol Clin North Am. 2013;46(5):759-778.

Complications

Learning Objectives 

Review potential operative complications

  1. Potential serious acute complications
    1. Surgical site infection
    2. Operative site hematoma
    3. Orbital hematoma with potential for visual loss.
    4. Extraocular muscle injury and entrapment
  2. Failure to achieve ideal fracture reduction
    1. Poor aesthetic contour/obvious facial asymmetry
    2. Palpable and/or visible bony step offs
  3. Hypertrophic scar formation
  4. Orbital/eyelid complications
    1. Eyelid malposition (e.g. ectropion or entropion)
    2. Globe malposition (e.g. hypothalmos or enophthalmos)
    3. Persistent Diplopia
    4. Lacrimal injury and epiphora
  5. Nerve injury
    1. Temporal branch of facial nerve (coronal incision)
    2. Supraorbital nerve (coronal or supraorbital incision)
    3. Infraorbital nerve (Eyelid, transconjunctival, or labial incisions)
  6. Alar base widening and nasal obstruction
References 
  1. PMID 24138736 Kochhar A, Byrne PJ: Surgical management of complex midfacial fractures. Otolaryngol Clin North Am. 2013;46(5):759-778.

Review

Review Questions 
  1. Name all of the vertical and horizontal buttresses of the midface.
  2. Describe the Markowitz classification system for naso-orbital ethmoid fractures.
  3. What are the four components of the classically described zygomaticomaxillary complex fracture?
  4. What are key features of different Le Fort fractures?
  5. In what situations would the bicoronal/hemicoronal flap be utilized for surgical exposure?
  6. Name the commonly described lower eyelid incisions.
  7. In what situations would extended transconjunctival approaches be considered useful?
  8. What are some of the most common complications associated with different surgical approaches to the midface?
Resources 

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Academy U: Resident Manual of Trauma to the Face, Head and Neck