Current trends in the management of maxillofacial gunshot injuries : a critical review

Introduction Firearm injuries continue to be a major public health problem. Herein, we review and evaluate the current trends in the management of maxillofacial gunshot injuries. Conclusion Ease of reduction and fixation of fractures, easier restoration of occlusion, prevention of contracture and displacement, ability to reduce displaced or avulsed teeth, early mandibular mobilization, less scarring, less anxiety and shorter hospital stay are among the many benefits associated with comprehensive definitive management of maxillofacial gunshot injuries. Introduction Firearm injuries continue to be a major public health problem. The management of patients with facial gunshot wounds varies and involves four main steps namely securing an airway, control of haemorrhage, identifying concomitant injuries and finally definitive repair of the facial deformity1–3. The emergency care of warfareinjured patients focuses first on the basics of resuscitation and status of the airway, as bleeding and subsequent swelling can compromise breathing. Also, similar to other trauma victims, advanced trauma life support must be provided when necessary. Airway control with an endotracheal tube or tracheostomy should be considered early, although, surprisingly, it is not always necessary. Haemodynamic resuscitation, followed by thorough patient evaluation, is done to rule out concomitant injuries often associated with warfare injuries. They may go unnoticed when attention is directed primarily to an extensive facial injury4–7. After early resuscitation, careful history and physical examination and paraclinical diagnostics are necessary for correct management. Surgical management of facial gunshot wounds is basically divided into three stages:(1) debridement, fracture stabilisa-tion, and primary closure; (2) reconstruction of hard tissues, provided soft tissue coverage is adequate; and (3) rehabilitation of the oral vestibule, alveolar ridge, and secondary correction of residual deformities and dental implants6,8. Herein, we review and evaluate the current trends in the management of maxillofacial gunshot injuries.


Introduction
Firearm injuries continue to be a major public health problem.The management of patients with facial gunshot wounds varies and involves four main steps namely securing an airway, control of haemorrhage, identifying concomitant injuries and finally definitive repair of the facial deformity [1][2][3] .
The emergency care of warfareinjured patients focuses first on the basics of resuscitation and status of the airway, as bleeding and subsequent swelling can compromise breathing.Also, similar to other trauma victims, advanced trauma life support must be provided when necessary.Airway control with an endotracheal tube or tracheostomy should be considered early, although, surprisingly, it is not always necessary.Haemodynamic resuscitation, followed by thorough patient evaluation, is done to rule out concomitant injuries often associated with warfare injuries.They may go unnoticed when attention is directed primarily to an extensive facial injury [4][5][6][7] .After early resuscitation, careful history and physical examination and paraclinical diagnostics are necessary for correct management.Surgical management of facial gunshot wounds is basically divided into three stages: (1)  debridement, fracture stabilisa-tion, and primary closure; (2) reconstruction of hard tissues, provided soft tissue coverage is adequate; and (3) rehabilitation of the oral vestibule, alveolar ridge, and secondary correction of residual deformities and dental implants 6,8 .Herein, we review and evaluate the current trends in the management of maxillofacial gunshot injuries.

Discussion
The authors have referenced some of their own studies in this review.These referenced studies have been conducted in accordance with the Declaration of Helsinki (1964) and the protocols of these studies have been approved by the relevant ethics committees related to the institution in which they were performed.All human subjects, in these referenced studies, gave informed consent to participate in these studies.

Debridement
Today, modern weaponry demands a modern approach to wound management.There are many concepts regarding wound debridement.The oldest belongs to Pirogov, who states that debridement is done to 'convert a crushed wound into an incised wound'.Regularly, contused, crushed, dead and dying wound edges must be excised to the point of active capillary bleeding so that the traumatic wound becomes an incised wound.The wound can then be sutured, allowing wound closure without suppuration, disintegration and suture breakdown.Struchkov and Berkutov recommended excising wound edges and the removal of all damaged and contaminated tissues.After debridement, wound edges should be well perfused and resistant to bacterial invasion to ensure rapid healing.
In military maxillofacial surgery, the basic principles of maxillofacial gunshot wound debridement formulated in the 1940s still hold.These principles require sparing of damaged tissues.Also, soft tissues of wound margins should be excised removing only the obvious nonviable tissues 9 .
Shvyrkov and Yanushevich 9 stated that in high-velocity projectile wounds the sparing of soft tissue in gunshot wound debridement may result in disability, multiple surgical interventions and prolonged duration of treatment.They recommended radical primary surgical debridement of gunshot wounds, and excision of soft tissue wound margins to the point of active capillary bleeding (indicative of normally functioning microcirculation system in the remaining viable soft tissues which heal rapidly).They excised 3.5 mm or more of skin and mucosa from wound margins.capillary bleeding and muscle jerk under the scalpel.However, the current trend in facial gunshot injuries comprises early conservative debridement, removal of traumatic tattoos, all non-viable tissues and attention to aesthetic result of the face in all steps using primary closure when possible and antibiotics 6,7 .

Fracture stabilisation
With regard to stabilisation, facial fractures resulting from gunshot injuries have been treated by many different methods including closed reduction, external pin fixation, internal wire fixation and open reduction and internal stable fixation (ORIF) using titanium plates and screws 6,7 .Before the development of reliable implants and instrumentation for rigid fixation, most facial fractures as a result of gunshot injuries were treated by closed reduction.The goal is correct reduction and stabilisation of facial bone fractures and minimal morbidity for patients.In most gunshot fractures, ORIF is necessary for optimal results.Before rigid fixation, closed techniques were preferred because of poor treatment outcomes with open reduction, which primarily involved internal wire fixation.These cases frequently developed infection and non-union.Conservative methods for the treatment of gunshot wound fractures have been recommended by many authors to avoid periosteal stripping of small, partially devitalised segments 10,11 .
Rana et al. 1 found MMF to be less time-consuming, technically easier to perform with a lower incidence of post-operative pain and less postoperative care was required along with shorter hospitalisation.
Other authors have recommended open reduction of comminuted mandibular fractures using K-wires as an internal splint, or removing the comminuted segments, crushing them and replacing them as a free graft 12 .In their study on facial fracture surgery, Dingman and Natvig 13 described the ORIF method for treating comminuted mandibular fractures using intraosseous wires or bone plates.A series of 32 low-velocity gunshot wounds to the mandible were reported by Neupert and Boyd 14 .Although they stated a preference for conservative management, 19 of 32 cases required open reduction with wire fixation or external pin fixation.They reported an infection rate of 27% with this treatment, whereas 18% developed continuity defects that required subsequent bone grafting.They attributed approximately half of the continuity defects to overly aggressive debridement and recommended conservative debridement of devitalised bone and teeth.Effective use of ORIF using the Association for the Study of Internal Fixation approach with large mandibular reconstruction plates has been reported by some investigators and stated that infection was caused mainly by loosening of hardware 15 .
In Rana's findings, infection did not occur in any of his patients treated via MMF; and 6.6% of infection occurred in patients treated with ORIF.This corresponds with the findings of Dingman and Natvig and others, who found infection rates around 13% in patients treated with ORIF.Newlands et al. 16 reported this complication in closed reduction in 10% of his cases.However, Neupert and Boyd reported an infection rate of 27% with ORIF treatment, which is a high rate.Motamedi 18,19 reported a 20% infection rate.

Occlusion
In a study on 30 patients treated with osteosynthesis, Okoturo et al. 17 reported malocclusion as the most frequent complication with 23.3% in ORIF.Smith and Johnson 15 reported 4.1% malocclusion in their retrospective study.All cases were of ORIF group.In another study, Baurmash 10 reported no malocclusion when closed reduction was used.Motamedi states that ORIF must be accompanied by arch bars, as arch bars remain to be the "mainstay" of management in gunshot patients even when ORIF is used 6,7,18,19 .
If arch bars and MMF are not used primarily, the occlusion may never be the same afterwards.

Primary closure
The soft tissue injuries in gunshot wounds are generally treated primarily along with fracture treatment via debridement and primary closure or combining, modifying and tailoring, useful local or regional flap techniques to fit the location of the injury, and to close the wound according to region.Reconstruction of soft tissue defects must be in accord with the reconstructive ladder, that is, simple primary closure in small wounds without tension and more complex reconstructive procedures including local flap, regional flap or free flaps in difficult wounds.Local undermining and use of regional soft tissue advancement rotation flaps for primary closure of maxillofacial soft tissue defects during the same operation has proved beneficial from both an aesthetic and functional point of view in gunshot injuries 4,6,7,[18][19][20] .

Reconstruction
Facial gunshot wounds frequently represent a complex set of challenges for the surgeon.Often as a result of assault, accident or suicide attempt, facial gunshot injuries cause significant soft tissue and bone defects 22,23 .Whereas past management favoured delayed reconstruction, contemporary trends more frequently favour immediate, definitive reconstruction 5,6,18,24,25  soft tissue coverage is crucial.In the acute and sub-acute setting, tissue coverage depends on (1) wound dimension, (2) overall patient status, and (3) the surgeon's prerogative.Shortly after injury, it is generally preferred to attain more conservative wound coverage.Although some surgeons advocate free flaps, others prefer "temporary" coverage and defer lengthy definite procedures to a time when the patient has stabilised.Examples of this coverage include use of galeal flaps and scalp flaps, backgrafting any defects created temporarily with xenografts or allografts 26,27 .

Timing reconstruction
Timing of definitive reconstruction is an area of continuing debate 28 .Although traditional approaches advised delayed reconstruction, the contemporary paradigm demonstrates success with more immediate definitive reconstruction within 24-48 h.
Proponents of delayed reconstruction have typically maintained that the prolonged period decreased infection rates, reduced necrotic debris, and allowed the surgeon to obtain a better idea of the extent of irreversible injury.Additionally, by allowing adequate time for oedema resolution, the decrease in inflammation provides for a better assessment of the pre-traumatic facial structure.However, in a review of 33 facial reconstructions, Vasconez et al. 29 observed similar infection rates between delayed and immediate post-gunshot wound reconstruction.The delayed group also demonstrated an increased incidence of wound contracture, which resulted in significantly more structural and functional deformity.In two other comparative reviews, Gruss et al. 30 and Vayvada et al. 31 also present improved results over traditional delayed approaches.Motamedi advocates early management of facial gunshot defects after primary stabilisation and assessment of all injuries; after meticulous conservative debridement of nonviable tissues and freshening of the wound, early primary reconstruction of bone defects was done using the fractured segments; the soft tissue was repaired with similar adjacent tissues (local or regional flaps) because he states these tissues have the same texture, colour and consistency as well as good blood circulation and less morbidity as compared with distant flaps 6,7,18,19 .

Hard tissue reconstruction
Correct positioning of the arch helps establish the proper facial width and frames the face.Improper reconstruction of the arch may result in incorrect framing for the remainder of the reconstruction.When a mandibular fracture is a component of gunshot wounds, re-establishing mandibular continuity 19 and thus restoring occlusion first is advisable 5,24,32,33 .This demands placement of arch bars to aid restoration of occlusion and facilitate the reconstruction of the remaining facial skeleton by creating a useful anatomic platform 19,[32][33][34] .External fixation may be prudent in the event of extensive bone comminution with minimal soft tissue damage 8,30,35 .While maintaining vital soft tissue coverage, external fixation allows bone regeneration and advancement without devascularising the underlying bone stock.This also stabilises the severely comminuted bone fragments and tends to promote the osteogenic character of fragments, facilitating bone healing and restoration of bone structure 8,30 .Internal plating should be used in the majority of the remaining instances in which bone fragments are large enough to accept screws.Although miniplates typically suffice for the cranium and midface, large (2.4 mm) locking plates are sometimes used in the mandible 5,30 .More often than not, the shattered and scattered bone can be found and secured to a reconstruction plate to obtain mandible continuity 18 .Midface and mandibular bone defects may need to be bone grafted 8,30,35 .Iliac crest bone graft is preferred for the mandible, as grafts similar in height and thick-ness to the mandible can be easily harvested 6,7,18,19 .Depending on the nature of these defects, iliac crest, cranium and rib are all reasonable options.In most cases, vascularised bone is not critical for reconstruction.

Defi nitive closure
Optimally, simple re-approximation of adjacent tissue can achieve definitive closure.Surprisingly, seemingly massive injuries can sometimes be closed primarily after treatment of hard tissues 18,22,23,30 .However, it is critical to avoid placing undue tension on local tissues.Undermining of skin edges, usually a significant facilitator of primary closure, should be done very conservatively.Some massive soft tissue defects secondary to gunshot wounds require free tissue transfer 36 .Over the past decade, advances in microvascular technique have established free flap transfer as the gold standard in the reconstruction of severe facial trauma 18,[22][23][24]27 ; however, they are not used primarily 6,7,18,19 .
Colour and texture matching is best done with local flaps.Providing enough tissue may require the use of a tissue expander secondarily.In the case where tissue expansion is desired, the wound should be maintained by dressing changes or vacuum-assisted therapy or covering with temporary skin graft until tissue expansion is complete.This approach accomplishes both wound conditioning providing adequate amount of local tissue needed for transfer without adversely affecting the donor site.
In cases that require multiple stage reconstruction, the free flap option is often best delayed until the exact nature of the defect is diagnosed and the patient is best prepared for this intervention.
For complex composite defects in the partially dentate patient, distraction osteogenesis is a promising technique that has been very useful for the reconstruction of these defects.To facilitate distraction, soft tissue reconstruction and healing should be complete to ensure integrity of the wound.By using distraction, the overall shape and amount of regenerate provides superior bone and soft tissue relationships and contour.Another well-observed benefit of distraction is the increase in native soft tissue.

Primary versus delayed reconstruction
The terms primary and delayed treatment are somewhat ambiguous and can be defined differently depending on the context 2,37-39 .For our purpose, primary treatment will be defined as initial treatment of a wound within 48 h (or the first major operation) with the intent to definitively manage all aspects of the injury.The goal of primary treatment is to repair the wound in such a way that both hard and soft tissues are restored and all wounds primarily closed.Delayed treatment will include all other forms of treatment later on, which are numerous.Classically, surgeons selecting delayed treatment have advocated debridement of soft tissue injuries and stabilising bony injuries.After oedema has resolved and the soft tissues have healed to cover the wounds, the final reconstruction is attempted.Staged repair of wounds also will be classified as a form of delayed treatment.
Without a doubt, the majority of penetrating wounds to the maxillofacial area are lacerations that are generally cleaned easily and closed primarily.Little controversy exists regarding this current standard of practice.For more complex penetrating wounds, however, the debate continues regarding which wounds should be treated primarily versus delayed.Proponents that favour primary treatment claim superior aesthetic and functional outcomes, whereas those of the delayed approach claim fewer complications due to infection.There is no soft tissue contracture or deformity in primary treatment, in addition coverage of soft tissue defects is easier and more anatomic; however, all surgeons must note that the need for secondary revisions in primary or secondary interventions of gunshot injuries of the face is the rule not the exception.
An obvious reason for delayed treatment is the inability for the patient to tolerate an operative intervention.Generally, one thinks in terms of the patient being medically stable, and once cleared by the trauma critical care team, operative intervention for the facial injuries can commence.Uncertain neurological or cervical spine status is an example.Even though the patient may be stable for surgery, unexpected or adverse outcomes of these injuries may result in questioning the decision for early facial surgery.A common reason for delaying treatment is to allow for resolution of oedema; however, after oedema subsides comprehensive treatment can be rendered in the first operation 18,19 .In cases of open fractures, the overlying soft tissue wounds can be closed primarily or in an interval fashion.Once the oedema has resolved in 7-10 days, bony defects can be repaired more easily.This technique not only allows for subtle deformities to be appreciated, but also prevents the undo retraction of the soft tissue that can produce poor outcomes in sites such as the peri-orbital region.Furthermore, properly identifying all deformities allows a single intervention rather than multiple insults to the soft tissue that produce fibrosis and decreased vascularity ultimately leading to thick stiff tissue and displacement of fractured segments.
Finally, there are times when a multidisciplinary approach is needed.Temporising wounds allows time for the team to be assembled, diagnostic imaging and models can be attained, and input from the various disciplines to be discussed.Patient/family input can be sought and informed consent secured.Once the patient is stable and optimally tuned for surgery, the best intervention can be delivered with hopes for the ideal outcome in the first major operation.
The general condition of the patient, timing and sequence of the operations, extent of damage, and proper application of appropriate surgical hardware for reconstruction and rehabilitation of patients with penetrating maxillofacial warfare injuries have proved to be influential to the final outcome and aesthetic result.These criteria dictate whether or not to use primary repair for the maxillofacial injury.The staged sequence of treatment has been described by Behnia, Motamedi, Clark, and others 4,7,[18][19][20]40 .
Even with a comprehensive primary management approach, penetrating maxillofacial warfare injuries are associated with a significant number of residual problems.The majority of these can be addressed on an outpatient basis.Nonetheless, treatment options necessitate clinical judgement and are based on similar experiences.No strict protocol can be uniformly applied to all patients.With the antibiotics and surgical hardware at hand, however, the majority of maxillofacial penetrating injuries can be treated definitively at the time of debridement when the general status of the patient permits and when this is in the best interest of the patient as the benefits are numerous 19 .

Conclusion
Based on this review, the current trend is to do as much as is practically possible for the gunshot patient with regard to hard and soft tissue reconstruction of the face and jaws in the first major operation even after 1 or 2 days.Even patients referred with wounds temporarily closed (to control haemorrhage) at the fronts or field hospital and then triaged and transferred to local hospitals can be treated comprehensively in the first stage.Treatment in such cases may be done upon arrival with the intent to debride and reconstruct the hard and soft tissues and to restore mandibular continuity (with They assessed muscle viability by the strength of Licensee OA Publishing London 2013.Creative Commons Attribution Licence (CC-BY) F : Motamedi MHK, Ebrahimi A, Shams A. Current trends in the management of maxillofacial gunshot injuries: a critical review.Annals of Oral & Maxillofacial Surgery 2013 Feb 01;1(1):8.