Wound ballistics of firearm-related injuries—Part 2: Mechanisms of skeletal injury and characteristics of maxillofacial ballistic trauma

Wound ballistics of firearm-related injuries—Part 2: Mechanisms of skeletal injury and characteristics of maxillofacial ballistic trauma

Int. J. Oral Maxillofac. Surg. 2015; 44: 67–78 http://dx.doi.org/10.1016/j.ijom.2014.07.012, available online at http://www.sciencedirect.com Review ...

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Int. J. Oral Maxillofac. Surg. 2015; 44: 67–78 http://dx.doi.org/10.1016/j.ijom.2014.07.012, available online at http://www.sciencedirect.com

Review Paper Trauma

Wound ballistics of firearm-related injuries—Part 2: Mechanisms of skeletal injury and characteristics of § maxillofacial ballistic trauma

P. K. Stefanopoulos, O. T. Soupiou, V. C. Pazarakiotis, K. Filippakis 401 General Army Hospital of Athens, Athens, Greece

P. K. Stefanopoulos, O.T. Soupiou, V.C. Pazarakiotis, K. Filippakis: Wound ballistics of firearm-related injuries—Part 2: Mechanisms of skeletal injury and characteristics of maxillofacial ballistic trauma. Int. J. Oral Maxillofac. Surg. 2015; 44: 67–78. # 2014 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Abstract. Maxillofacial firearm-related injuries vary in extent and severity because of the characteristics and behaviour of the projectile(s), and the complexity of the anatomical structures involved, whereas the degree of tissue disruption is also affected by the distance of the shot. In low-energy injuries there is limited damage to the underlying skeleton, which usually dominates the clinical picture, dictating a more straightforward therapeutic approach. Highenergy injuries are associated with extensive hard and soft tissue disruption, and are characterized by a surrounding zone of damaged tissue that is prone to progressive necrosis as a result of compromised blood supply and wound sepsis. Current treatment protocols for these injuries emphasize the importance of serial debridement for effective wound control while favouring early definitive reconstruction.

Although firearm-related injuries inflicted to the maxillofacial region frequently affect adjacent structures of the neurocranium or neck, by current criteria the head, face, and neck are considered separately in the context of ballistic trauma.1–3 § The complete paper is respectfully dedicated to Professor Daniel M. Laskin.

0901-5027/01067 + 012

This is justified by the complex anatomy and articulation of the maxillofacial structures resulting in different injury patterns, which are also more difficult to reproduce in ballistic models.2,4–6 As a result of these difficulties, there is a limited number of experimental studies investigating the mechanisms of maxillofacial missile injuries,5–8 by contrast to the

Keywords: Wound ballistics; Gunshot wounds; Missile injuries; Maxillofacial injuries; Maxillofacial trauma. Accepted for publication 21 July 2014 Available online 13 August 2014

extensive literature dealing with their treatment. In this second part of a review article on wound ballistics, specific mechanisms of ballistic bone penetration are described as a basis for understanding the pathophysiology of maxillofacial ballistic trauma. Maxillofacial gunshot (bullet) and shotgun (pellet) injuries are then presented,

# 2014 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

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with respect to injury patterns commonly encountered and their surgical implications. Mechanisms of ballistic bone injury

Bone tissue offers increased resistance to penetration compared to soft tissue due to its hardness,9,10 in addition to its greater density and strength.11 With bone impacts, both the retardant effect on the penetrating missile and the potential for energy transfer are marked.11–13 Under these circumstances, the critical factors for injury are the limited capacity of osseous tissue to absorb the energy of impact without fracturing10 and the toughness of cortical bone, which determines the extent of crack propagation.14,15 Furthermore, recent evidence suggests that there are similarities between ballistic fractures in bone and glass, indicating that under the energy transfer associated with ballistic injuries, bone behaves as a brittle material.16 In a classic series of experiments, Huelke et al.,17–20 using human cadaveric femurs as targets, showed that the degree of bone injury produced by spherical projectiles increased with progressively higher velocities, ranging in severity from incomplete penetration or simple ‘drillhole’ defects, to comminuted fractures with complete separation of the bone ends. These authors demonstrated mathematically that the energy expended by the projectile penetrating normal and mildly osteoporotic femurs may actually be a linear rather than a quadratic function of the impact velocity, due to the resistance of bone.20 This relationship was depicted by a drop in the percentage of energy loss during penetration as the impact velocity was increased,17,19 because velocity affects the kinetic energy of the projectile raised to the second power, much more than it does with the amount of the energy transferred to the bone. In these series,19 impacts to the dense cortical bone of the femoral shaft caused significantly greater energy expenditure than those directed to the metaphyseal region where cancellous bone predominates. Also, comminuted fractures were more common in the shaft, which was related to the narrow tubular configuration of the cortex in this area, the latter feature effectively distributing the loading generated by the impact around the entire periphery of the bone.19,20 Bone marrow has fluid properties allowing cavity formation within it by highvelocity projectiles,11,21 also suggested by Huelke et al.17,19 following penetration of the distal metaphyseal regions of femurs. In those experiments, defects of

explosive character at the exit site were observed as a manifestation of cavitational effect by projectiles penetrating at velocities above 300–500 m/s, in extreme cases resulting in complete separation of the femoral condyles from the shaft.19 Contrary to soft tissue, cavitation in bone is not followed by collapse of the cavity walls due to lack of elasticity, but rather the hydraulic pressure built-up results in immediate pulverization of the surrounding bone structure.11,19 According to Kneubuehl,22 this mechanism is primarily responsible for ballistic bone fractures, whereas in the absence of bone marrow, as in flat bones, bullets tend to create drillhole defects. Cavitation was not prominent with shaft impacts in the series of Huelke et al.,20 due to the limited bone marrow contained in these parts. In a final series,23 Harger and Huelke also showed that, at higher impact velocities, the diameter of the projectile has greater influence than its mass on the energy expenditure and the resultant bone damage, which is consistent with the magnitude of cavitational effects as related to the presenting area of the penetrating body. They concluded that the bone damage produced as a result of cavitation depends primarily on projectile velocity and size,19 whereas at lower velocities, cavitation is not a prominent feature and the mass of the projectile becomes relatively more important.23 It follows that the energy transfer in ballistic bone injuries is a more complex phenomenon than in soft tissue; admittedly it also remains less well understood.16,24 The drag force opposing the motion of the projectile within bone has different characteristics than in soft tissue, being independent of the projectile velocity according to Harvey et al.25 Actually, because the amount of energy transferred during ballistic penetration is influenced by the time spent by the bullet in contact with the bone, which is inversely proportional to its velocity, it is possible for a relatively slow nondeforming handgun bullet to cause more damage than a stable rifle bullet.10,21,22 Microfractures created by the penetrating projectile within the cortical bone substance8,16 can partly explain this intricate response. These microfractures tend to radiate around the wound channel and beneath the impact site,16 creating an area of lesser resistance ahead of the advancing projectile so that it makes its way through the bone more easily. A high-velocity bullet upon impact is expected to produce such defects more extensively, thereafter requiring relatively lower amounts of energy for the penetration process.26

Military and hunting rifles, as well as Magnum handguns, produce high-energy injuries with extensive bone comminution, documented both in experimental studies27,28 and retrospective reviews.29 It has also been observed that maxillofacial injuries by military rifle bullets at close range show greater comminution than those inflicted from a long distance with much of the bullet’s energy used up.30 However, Clasper and Hodgetts31 have reported an unusual case of accidental point-blank wounding by an M16 rifle bullet of current (NATO) design, resulting in a drill-hole defect in the humeral head, despite an apparently oblique course of the projectile through bone; the low-energy transfer in this case was explained by the bullet penetrating mostly cancellous bone, and the short wound track through soft tissue due to the low muscle bulk of the area.31 Undoubtedly, an important contributing factor for such a low-energy bone injury despite high impact velocity is the streamlined shape of military rifle bullets eliciting lower drag forces. This could be validated in correlation with a recently published finite element analysis of mandibular ballistic injuries, which revealed significantly less energy loss by 7.62-mm military rifle bullets compared with 6.3mm steel spheres, when the former penetrated at high velocities perpendicular to the bone surface.6 High-velocity missiles penetrating into soft tissue are capable of causing indirect fractures of adjacent long bones by the expansion of the temporary cavity in their wake.12,25,32,33 These fractures represent a definite feature of high-energy transfer,13,34,35 notwithstanding they are simple rather than comminuted.12,32,33,35 Indirect fractures of the skull base occur with highenergy penetrating head trauma, but because of the unyielding conditions within the cranial cavity, even handgun bullets penetrating intracranially can create enough hydraulic pressure to cause linear fractures of the thin orbital plates, manifesting as peri-orbital haematoma.21,22,36,37 The autopsy on President Lincoln showed shattered orbits, supposedly from this mechanism.38 Ballistic fractures are almost always accompanied by damage to the surrounding soft tissues, which may be augmented by bone fragmentation, especially in the skull or pelvis.11 Bone fragments created by high-velocity penetration are dispersed in all directions.8,10 Harvey et al.25 suggested that fragments driven out into the adjacent temporary cavity are forced back with the collapse of the cavity, retaining a connection with the parent bone possibly

Wound ballistics of firearm-related injuries—Part 2 by periosteal attachments. Beyer39 pointed out that in battle wounds, bone fragments were not always retained in close approximation to the shattered bone, although this did not indicate their importance as wounding agents. Other experts have also stated that bone fragments do not receive enough energy to produce further wounding.22,40 However, experimental studies with high-velocity spherical projectiles have demonstrated that bone fragments are hurled forward as secondary missiles and may exit the wound in the direction of the bullet.41 Contact with bone may also cause the projectile to tumble, deform, or fragment,21 resulting in further soft tissue injury.11,12 Depending on the angle of impact and the projectile velocity, the bullet can ricochet off the bone surface and follow an altered trajectory at reduced velocity.42 General features of maxillofacial ballistic injuries

Maxillofacial firearm-related injuries are customarily classified as either penetrating or perforating43–48; each of these categories is determined by the terminal location of the projectile and its wounding effects.49 Penetrating wounds are caused by missiles of low impact velocity, such as handgun bullets, with a small point of entry leading to the missile embedded in tissue.4,45,48 Perforating wounds are typically produced by higher velocity bullets, which create an exit wound that is often larger than the entrance.43,44,46 A third category is the avulsive or ablative injuries, characterized by significant bone and soft tissue loss.4,46,48 These are caused either by close-range shotgun blasts, with avulsion created by multiple pellets close to each other, or by high-velocity rifle bullets which may produce massive exit wounds as a result of bullet tumbling, bone fragmentation, or both46,50; in the latter case, the avulsive wound may be considered as part of a perforating injury.49 Maxillofacial firearm injuries vary in their clinical presentation depending on the anatomical structures involved. In the upper face, injury to the orbital or cranial

contents is the overriding concern,44,51–55 whereas in the lower face, damage to the intraoral lining almost invariably complicates ballistic fractures.56–59 Mandibular injuries often result in bone comminution,60,61 occurring with little relation to the projectile calibre or velocity,45,62,63 particularly in the anterior mandible, which is supported by little soft tissue envelope and behaves like a contoured long bone.48 Contrary to previous models viewing an articulated long bone at the moment of bullet impact as a beam loaded in bending,64 Kieser et al.16 have suggested that the projectile does not deform the bone sufficiently to create opposite areas of tension and compression preceding non-ballistic fractures, because of the enormous forces exerted over a small area at a high rate. This seems also appropriate to the mandibular body, representing a fundamental difference from blunt trauma. Tangential bullet trajectories through the anterior mandible can cause avulsive injuries.44 The bones of the midface are also prone to comminution due to their thin construction and honeycomb pattern,45,48,61,65 but because of these very characteristics they are capable of absorbing limited amounts of energy and the resultant fractures are generally less severe than those affecting the mandible.61 Despite the potentially destructive effect of ballistic forces, between 15% and 40% of facial wounds involve only soft tissue.1,51,61,66–69 Gunshot injury patterns

Gunshot wounds to the face, previously classified as ‘low-velocity’ or ‘high-velocity’,1,45,51,65 are now categorized according to the energy transfer characteristics along the missile path, which correlate with the magnitude of tissue injury and tissue loss56,68 (Table 1). Injuries involving low energy transfer typically cause non-avulsive, penetrating or perforating wounds,70 usually with some comminution at the point of bone penetration.65,71,72 High-energy ballistic injuries, commonly produced by rifle bullets, are recognized by their extensive, often avulsive nature, involving hard and soft tissues,47,52,70,73 although after

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re-approximation of the wound edges they may prove to have little actual soft tissue loss.43,68,74–77 Their distinctive feature, however, is the extent of non-viable tissue, which may be greater than first apparent,73 as a result of the damage produced beyond the grossly evident wound.46 This constitutes the zone of injury, which is an area of evolving tissue deterioration resulting from inflammation and disturbed blood circulation.78,79 Above all, potentially lethal or disabling effects depend more upon the anatomical track of the missile rather than its energy transfer characteristics.80,81 Clark et al.56 analyzed 250 facial gunshot wounds treated during two periods, based on the predicted bullet path, with respect to the four anatomical units of the facial skeleton,82,83 namely the mandible, lower midface with tooth-bearing portions of the jaws, orbital region, and frontal cranium. The frontal cranium was involved in the majority of cases attributed to a large number of assaults.56 Extensive injuries involving multiple anatomical areas of the face, comprising 43 cases (24%) of the more recent subgroup in the above study, did not correspond to these anatomical patterns.56 Multiple involvement is a common feature among high-energy gunshot injuries.60,75 In several other studies, the classical division into upper, middle, and lower facial thirds is widely used for describing the location of gunshot wounds to the face,51,55,84 but there is a tendency to exclude those injuries primarily affecting the frontal region as representing intracranial injuries.2,61,67,69,85 A more detailed method of classification proposed by Be´nateau et al.,86 distinguishes central from lateral facial areas, each divided into lower (mandible), middle (maxilla), and upper units (Fig. 1). The site of entry and the estimated trajectory of the projectile allow a general impression of the structures disrupted and may predict, with a certain safety margin, possible life-threatening complications, although the unpredictable path of bullets due to the ricocheting effect of bone surfaces51 reduces the diagnostic value of classifications based on such features.1,87,88 In a retrospective review of 100 patients,

Table 1. General features of maxillofacial gunshot and close-range shotgun wounds according to energy transfer characteristics. Gunshot (bullet) wounds

Wound characteristics Low-energy

High-energy

Type of injury

Usually penetrating, with limited bone comminution

Tissue loss Zone of injury

Little Limited

Usually perforating, potentially avulsive; associated with grossly comminuted fractures Variable Extensive

Shotgun (pellet) wounds Avulsive (penetrating or perforating); associated with grossly comminuted fractures Massive Extensive

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Stefanopoulos et al. of handgun cartridges,36 may involve destruction of the chin and lower lip, and loss of the symphysis.62 Although the damage inflicted indicates a high-energy injury,84 it is not the result of the striking energy of the projectile.98 Lateral and posterior mandible

Fig. 1. Classification scheme for maxillofacial ballistic injuries, as described by Be´nateau et al.86 M: medial face; L: lateral face; 1: mandible; 2: lower midface (maxilla); 3: upper midface (orbits and nasoethmoidal complex). Injuries are designated by their subunit components, each recorded as medial (M) or lateral–right (R) or left (L), followed by the number indicating the level.

Dolin et al.85 demonstrated transfacial bullet trajectories in three entry zones, lateral and posterior face (A), anterior midface (B), and anterior mandible (C), and found that the need for airway control, commonly with orotracheal intubation, most often arose with trajectories through zones B and C. The need for tracheostomy in the acute setting is an uncommon scenario,85 affecting 8–13% of the patients in recent studies.69,76,89 However, among 75 surviving firearm victims reviewed by Hollier et al.,66 16 required tracheostomy, all of whom had suffered injuries to the lower third of the face. High-energy rifle injuries of the mandible are especially likely to cause significant airway compromise requiring intervention.90 Angiographic evaluation for possible major vascular injury may also be indicated depending on the path of the projectile.1,2,67,69,85,87,91,92 Anterior face

Severe gunshot and shotgun injuries of the face are commonly related to suicide attempts, with the gun fired under the chin while the neck is often hyper-extended,

resulting in a non-lethal wound.49,58,62,74, 75,93,94 When applied in this manner, the weapon produces a typical pattern of injury involving the midportion of the mandible, with a variable extent into the central or lateral midfacial region.93,95 Bullets that deform or fragment early by impact with the dense mandibular bone, produce greater tissue disruption.96 With a more vertically directed aim, penetration of the frontal sinus or anterior skull base occurs.49,52 When this type of injury is produced by a rifle bullet, a large exit wound is created (Fig. 2). On the other hand, it is not unusual to find a lowvelocity bullet retained subcutaneously at its point of exit through the frontal bone, owing to the toughness and elastic properties of the scalp.94,97 Alternatively, the muzzle may be inserted into the mouth, sparing the mandible.52,96 When a handgun is fired submentally in hard contact against the skin, the propellant gases expelled from the muzzle expand within the tissues, creating an explosive effect which may resemble in severity wounds from rifles and shotguns. Massive injuries of this type, which are more common with high-power loadings

Low-velocity bullets penetrating the lower face become rapidly destabilized upon encounter with the mandible99 and can easily be retained within the tissues.100 The resultant fracture may be accompanied by more extensive soft tissue trauma than expected, resulting from bullet tumbling and also bone and tooth fragments driven deeply into the floor of the mouth and tongue.58,61,92,100 Injuries to these areas cause significant bleeding and can evolve into gross swelling and haematoma, with an immediate threat for the airway.69,72,100 In the case of high-energy fractures, extensive comminution is seen in addition, with splinters from shattered bone and teeth bursting outwards and creating an exit wound of explosive type.65,101,102 Whitlock and Kendrick45 reported a case of assault rifle injury with an exit wound just above the entrance of the bullet, apparently created by a piece of mandibular bone expelled in a direction opposite to that of the bullet. On the other extreme, a high-velocity bullet may traverse the soft tissues of the cheeks through the open mouth without encountering bony structures, resulting in low-energy transfer.103 Midface

In large studies excluding or containing limited numbers of self-inflicted injuries,2,66,67 the midface rather than the lower face presents as the most frequently damaged facial area. Depending on the direction of the shot, midfacial entry sites are more likely to be associated with intracranial penetration,2,66 and because of this risk in the case of rifle injuries, only victims receiving a tangential or sideways hit usually survive.58,60 Military rifle bullets completely traverse the facial skeleton remaining largely stable throughout their path,99 except when hitting from a long distance. Lower midfacial injuries involve the upper alveolus, palate, and maxillary sinuses,45,68,85,92 although the typical bilateral patterns of Le Fort fractures are unusual.44,45,61 In high-energy injuries, there may be wide exposure of the maxillary sinus to the outside or destruction of the nasal pyramid.44,46 Damage to the

Wound ballistics of firearm-related injuries—Part 2

Fig. 2. Reformatted three-dimensional computed tomography (CT) image (postoperative) of a self-inflicted craniofacial injury from a military rifle bullet treated 15 years ago. The high-energy nature of the injury is indicated by the extent of frontal bone debridement performed by the neurosurgical team around the exit site, as well as by the associated fracture in the orbitonasoethmoidal complex and lower midface. A concomitant large palatal defect, which was intractable to initial attempts at closing, was eventually closed with a tongue flap (courtesy of I. Michaelides, DMD, COL, Dental Corps, Hellenic Army).

globe is most common with gunshot injuries affecting the orbital region and nasoethmoidal complex, and occasionally a bullet penetrating the orbit will exit through the contralateral temporomandibular joint (TMJ) region.68 Other structures that may be involved creating long-term surgical problems are the lacrimal apparatus, the facial nerve, and the parotid gland.1,46,69 Mechanisms of indirect injury

The air cavities interspersed among the delicate bony structures of the midface and the absence of bulky muscles generally tend to mitigate cavitational effects produced by high-velocity missiles in this region.13,79,104 It should be noted, however, that the posterior floor of the mouth with the surrounding bone forms a compact area, which can effectively accommodate cavitational changes. Also, ballistic penetration into the posterior mandible is generally associated with large amounts of energy transfer compared to the midface, due to the

greater overall tissue volume and density resulting in longer wound tracks.7 Formation of a large temporary cavity in this region has been demonstrated by Chinese researchers,105,106 produced by a 5.56-mm steel sphere, which was fired at 1500 m/s into the masseteric area of a dog. Using the same canine model, with spherical projectiles fired at 1300 m/s, they also detected associated vascular damage extending beyond the wound edges, as a result of blunt injury induced by the expanding cavity.105 High-velocity projectiles have been shown to cause extensive injury to the endothelial surface of blood vessels locally and at some distance from the wound,106,107 presumably as a result of the temporary cavity and stress waves produced107; endothelial injury, albeit largely reversible,106 appears to be an important component in the pathology of the zone of injury. In areas where skin is firmly attached to bone, unique cavitational effects have been observed with high-velocity missile impact. In the face and head, distant and intermediate-range entrance wounds

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created by powerful rifle bullets may have a stellate appearance similar to that seen with contact gunshot injuries.36,108 This occurs because of the sudden expansion of a temporary cavity as the bullet encounters bone after penetration of the scalp or facial skin, which causes large tears to radiate from the initially round entrance hole, producing the resultant gaping wound. Lethal wounds of this type in the face may appear 25–30 mm in diameter.109 Ragsdale and Josselson,27 using highspeed films of experimental shots at gelatin-encased target bones, demonstrated apparently explosive decompression of an expanding temporary cavity by dissection along the proximal gelatin–bone interface. It has been suggested that the resultant stripping of the investing soft tissues around the site of the missile wound is likely to devascularize an underlying area of bone comminution.11,27 There is convincing evidence that highenergy maxillofacial gunshot injuries may be associated with indirect brain damage.106 In a case reported by Treib et al.,110 a World War II veteran presented with epileptic seizures, which reappeared after an asymptomatic period of nearly 40 years, related to a wartime facial gunshot wound. That injury had been inflicted by a powerful military pistol at close range; the bullet entered the face at the nasion without penetrating the cranial cavity, to be found lodged near the second cervical vertebra. The patient had also suffered Le Fort II and III fractures from blunt trauma. The authors suggested that the hydrodynamic effect of the bullet caused indirect damage to the brain, which presumably resulted in a slow degenerative process eventually reactivating the epileptogenic focus.110 In another case, a soldier seriously wounded to the face by a military rifle bullet, which passed inferior to the base of the skull, suffered traumatic brain injury (TBI) with headaches, vomiting, dizziness, and post-concussional ‘frenzies’ 1 year after the incident.111 The occurrence of indirect cerebral damage in maxillofacial gunshot injuries has been studied extensively by Tan et al.,112 using steel spheres fired at 1400 m/s and 800 m/s through the left masseteric area in two respective groups of dogs. The faster projectiles produced larger maxillofacial wounds, also associated with a significantly higher incidence of gross cerebral injury, which affected 71.7% of the animals as compared to only 7.1% of those in the lower velocity group. In a subsequent, sophisticated study,7 the same group of authors investigated the mechanism of the cerebral injury using

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high-velocity spherical projectiles as well as assault rifle bullets targeted at the mandible and maxilla of pig heads. Based on the peak values of the acceleration forces generated, they concluded that the predominant causative mechanism for the associated cerebral damage was the strong vibration of the head due to the sustained momentary acceleration. This was supported by the more severe pathological changes in the basal regions of the brains observed previously,112 as these areas are subjected to shearing forces by the rough interior surface of the skull base.7 A relevant finding was the high peak values of acceleration particularly in the case of mandibular injuries incurred by the M16 assault rifle, not only in the direction of the shot line but also perpendicular to that7; this could be the result of the radial expansion of large temporary cavities produced by M16 rifle bullets. Tan et al.7 felt that the pressure changes transmitted to the brain due to the ballistic pressure wave of the impact, as well as the bony stress sustained by the cranium, both participate to a lesser extent than the vibration mechanism in the development of cerebral damage. However, the peak values of ballistic pressure waves recorded during wounding by rifle bullets especially to the mandibular area7 were comparable to pressure ranges known to cause TBI in laboratory animals (approximately 103– 207 kPa)113. Since these recordings were obtained by pressure wave transducers inserted into the brain substance,7 they may actually have reflected more accurately the ensuing changes within the cranial cavity. Banks44 previously noted that bullets striking the mandible may cause indirect subgingival fractures of teeth at a distance from the impact site, which he attributed to shock waves transmitted through the dense bone of the mandible. The impact to the mandible may produce a stress concentration effect, and possibly hydrodynamic pressure transmission through the periodontal space, which presumably could cause either fracture or even extrusion of a tooth (Fig. 3). Stress distribution patterns following ballistic penetration of the mandibular angle have been demonstrated extending from the point of impact to the ipsilateral condylar neck and to the mandibular body anteriorly.5,6 Shotgun injuries

Previous classifications of shotgun injuries were based on information or prediction regarding the distance of shooting as related to pellet scatter, which may be unreliable

Fig. 3. Preoperative radiograph showing an oblique fracture of the mandibular body (small long arrow), due to a handgun injury with bullet ricochet off the buccal cortex. The deformed lead bullet is indicated by the large arrow (this bullet is also shown after its removal in Fig. 10 of Part 1). A missing premolar tooth (indicated by the two short arrows) initially passed unnoticed in this emergency radiograph, but was found later with the aid of a panoramic radiograph lodged into the dorsum of the tongue through a deep laceration. The tooth was expelled intact, apparently by an indirect mechanism of transmitted force as its socket was not in the line of fracture. This case also illustrates the importance of radiographic examination for the location of missing teeth in the injured patient (courtesy of I. Michaelides, DMD, COL, Dental Corps, Hellenic Army).

(Fig. 4). Deposition of soot in the skin is evidence of a blast within approximately 30 cm, although there are rare exceptions.36 Clark et al.56 have described four general anatomical areas of involvement in closerange shotgun injuries, which correspond to the level of the wound and its primary location affecting medial or lateral facial structures, namely the central face, the lateral mandible, the lateral midface and orbit, and the lateral cranio-orbital region (Fig. 5). Lower facial distributions are more common, reflecting the high incidence of suicide attempts with shotguns discharged under the mandible.52,56 The destructive capacity of shotguns is greater than their muzzle velocity would suggest (average 306 m/s),88 as it is primarily determined by the mass of the shot.47,114,115 Furthermore, because of the ballistically unfavourable design of pellets, they tend to remain in the wound, resulting in full dissipation of energy in tissue.52,115 The most destructive pattern of injury

produced by shotguns occurs with contact discharge, with the rapidly expanding gases entering the wound, along with the wadding and pellets.36,52 Lethal self-inflicted submental blasts consist of extensive destruction of all bony and soft tissue structures in the path of the wound, with frequent penetration of the skull in the case of 12-gauge shotguns,116 whereas in survivors, the central face may be blown off.52,58,117,118 In midfacial injuries, the discharge typically creates a ‘cone’ of tissue destruction, which after debridement leaves a large defect without support.75 Close-range and contact shotgun injuries are often superficially indistinguishable from the explosive exit wound and the underlying muscular damage produced by rifle bullets.44,45,47,65,119 However, in shotgun wounds, the zone of injury can be even wider, indicating their high-energy nature,52,54,56,58,115 also associated with a high incidence of infection.114,120 Maintenance of the airway is usually required with these injuries.69,114

Wound ballistics of firearm-related injuries—Part 2

Fig. 4. Panoramic radiograph of a shotgun injury to the lower lateral face, with surprisingly minor bone injury due to the distance of the shooting and the oblique direction of the shot string with respect to the bone surface. From the main entrance wound corresponding to the circular pellet concentration in the premolar area, ricochet phenomenon and probably the so-called ‘billiard ball’ effect resulted in some pellets being distributed further posteriorly along the external oblique line. The pellets appeared undeformed, indicating steel construction; the reverse is true for lead pellets striking bone.

Implications for the management of high-energy missile injuries

Whereas understanding of wound ballistics facilitates the assessment of tissue damage following ballistic penetration, this cannot predict how much of the injured tissue will eventually fail in high-energy injuries.24,121 In these injuries secondary tissue damage within the zone of extravasation results from early ischaemia and vascular

compromise induced by high-energy ballistic penetration,122 essentially constituting the clinically defined zone of injury. In view of this, removal of dead or devitalized tissue remains a key component of wound management, providing the usual rationale for surgical debridement.122 A delay in that action for 6–12 h appears to complicate further treatment in animal wounds, as it has been associated with increased tissue necrosis, whereas beyond that period the

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identification of necrotic margins also becomes more difficult.123 These observations confirm the progressive pattern of tissue necrosis in high-energy ballistic injuries, which, however, is not directly related to the energy transferred but rather to the amount of tissue originally destroyed.124 In high-energy injuries of the maxillofacial region, severely damaged tissue is further compromised by bacterial contamination, leading to wound sepsis with ongoing loss of bone and soft tissue despite the rich blood supply of the area, especially when primary closure under tension is attempted.1,58,125,126 In experimental injuries, post-traumatic necrosis has been shown to affect skin and oral mucosa within a zone of 2 mm, whereas in muscle tissue it extended up to 8 mm from the wound track. It also affected bone following a more persistent course for 3–7 days after injury, to a depth of 5 mm from the fracture ends.106 Such an evolving pattern of tissue necrosis is difficult to predict in the clinical setting127,128; however, it can be confirmed by wound re-exploration every 24–36 h over a period of a few days,56,115,129 and this watchful approach with serial wound debridement has become the basis of the current treatment protocols, allowing for demarcation of the zone of injury as early as possible, before definitive management is undertaken.47,56,71,74,130 Wound infection

Fig. 5. General patterns of possible extent of bone loss (shaded areas) in close-range shotgun injuries, with respect to midline (a) or lateral (b) maxillofacial involvement, as classified by Clark et al.56 and Manson68. I: central face; II: lateral mandible; III: lateral midface and orbit; IV: orbit and frontal cranium. Defective areas are surrounded by damaged bone and soft tissue (not shown), constituting the zone of injury (based on images originally published in ‘‘McCarthy JG, ed.: Plastic surgery. Saunders, 1990: p. 1128’’; with kind permission of Paul N. Manson).

Missile wounds become contaminated during their formation by the penetrating projectile and also secondarily through their exposed surface.131 Experimental animal studies, with simulation of field conditions using unclear uniforms over the wounded areas,132 suggested that high-energy injuries from military rifle bullets with large exit wounds were prone to bacterial contamination demonstrated as early as 6 h following wounding. While this was prevented by penicillin administration, secondary contamination invariably followed a delay in surgical treatment, with bacterial counts indicating infection as a result of invasion from the wound environment rather than of primary inoculation by the bullet.132 These observations can be extrapolated to maxillofacial injuries with respect to secondary wound contamination from oronasal secretions, indicating the need for early control with tension-free watertight closure of the mucosa.61,73 Other studies suggest that, unless highly contaminated or complicated with bone injury, soft tissue missile injuries may be associated with only a moderate risk of

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infection.133 Contamination of ballistic fractures of long bones has been addressed by Clasper et al.,32 who showed that the fracture site should be considered highly contaminated, in proportion with the degree of bone comminution, whereas bacterial invasion of soft tissue mainly occurs along tissue planes previously separated by the cavitation process, with limited intramuscular spread. Based on these observations, they favoured more radical debridement of bone fragments, whereas for soft tissue they recommended thorough irrigation of tissue planes, minimal excision of skin edges, and excision of muscle depending on clinical appearance with selective removal of only necrotic, non-contractile tissue.32 The only experimental quantitative bacteriological study for maxillofacial ballistic injuries134 revealed bacterial invasion of soft tissue up to 5 mm around the wound track in dogs at 6 h of injury, whereas beyond that period bacterial counts increased to critical levels for developing infection.134,135 These studies support early antibiotic administration, since a delay of 6 h renders such treatment ineffective,133 whereas current guidelines for combat-related injuries recommend short courses of antibiotics to be started within 3 h of injury.136 The impact of the zone of injury on early reconstruction

In recent decades there has been a shift towards primary repair of avulsive ballistic injuries of the face to prevent soft tissue contracture,74,137,138 which is greatly facilitated by the utilization of free tissue transfer techniques.47,131,139,140 Such a need commonly appears with major defects of the mandible involving the symphysis.52 In this type of injury, early definitive reconstruction is indicated for functional as well as psychological reasons (Hammer B, personal communication), preferably with composite free tissue transfer to provide intraoral lining, skin cover, and bone support in one stage.52,59,74,75,95,141–143 When microsurgical reconstruction is indicated, conception of the zone of injury in its true extent, in addition to that of the primary defect, is fundamental.48,54,56,73,78 Experimental work with animal wounds105,106 suggests a margin of 3 cm from the wound track beyond which microvascular anastomoses can be placed safely. Furthermore, significantly better results were reported with short-term patency of facial vessels anastomosed 3 or more days after injury, compared to those repairs performed immediately after initial

debridement.105,106 These observations are in accordance with experience from the immediate management of combat-related injuries, for which deferment of free tissue transfer has been recommended.77 In the case of civilian high-energy facial wounds, however, it has been suggested that they are not so contaminated initially as to warrant sequential debridement and delay.84 If so, a window of opportunity may exist for immediate definitive treatment once all devitalized tissues have been adequately debrided,74,96 which in the case of microsurgical reconstruction will take advantage of the initial period while the recipient vessels are still devoid of spasm and fibrosis.54 This is mainly supported by two studies,52,84 both of which reported good results based on a limited number of patients, a fact that in one case caused severe criticism.117 It is also notable that proponents of this aggressive approach are in favour of ‘wide’ or radical debridement.52,74,96 Such practice may emerge as a paradigm shift analogous to the ‘fix and flap’ technique for high-energy injuries of the extremities,74,144 but its safety and specific indications have apparently to be determined by larger studies. In conclusion, ballistic penetration to the face is usually associated with structural damage of the underlying skeleton. In high-energy injuries, including those inflicted by shotguns, there is more extensive bone destruction, frequently with frank tissue avulsion. Cavitational changes induced by high-velocity projectiles may compound bone comminution and devitalization. As a consequence, the treatment of these injuries is complicated by an evolving pattern of tissue necrosis within the zone of injury, which ideally should be controlled during the early phase with adequate dewhile prevention of bridement, secondary contamination of fracture sites should also be addressed. Funding

None. Competing interests

None declared. Ethical approval

Not required. Patient consent

Not required.

Acknowledgements. The authors wish to

thank Dr Chris Giannou for critical review of the manuscript.

References 1. Cole RD, Browne JD, Phipps CD. Gunshot wounds to the mandible and midface: evaluation, treatment, and avoidance of complications. Otolaryngol Head Neck Surg 1994;111:739–45. 2. Chen AY, Stewart MG, Raup G. Penetrating injuries of the face. Otolaryngol Head Neck Surg 1996;115:464–70. 3. Breeze J, Bryant D. Current concepts in the epidemiology and management of battlefield head, face and neck trauma. J R Army Med Corps 2009;155:274–8. 4. Cunningham LL, Haug RH, Ford J. Firearm injuries to the maxillofacial region: an overview of current thoughts regarding demographics, pathophysiology, and management. J Oral Maxillofac Surg 2003;61: 932–42. 5. Tang Z, Zhou Z, Zhang G, Chen Y, Lei T, Tan Y. Establishment of a three-dimensional finite element model for gunshot wounds to the human mandible. J Med Coll PLA 2012;27:87–100. 6. Tang Z, Tu W, Zhang G, Chen Y, Lei T, Tan Y. Dynamic simulation and preliminary finite element analysis of gunshot wounds to the human mandible. Injury 2012;43: 660–5. 7. Tan Y, Zhou S, Jiang H. Biomechanical changes in the head associated with penetrating injuries of the maxilla and mandible: an experimental investigation. J Oral Maxillofac Surg 2002;60:552–6. 8. Chen Y, Miao Y, Xu C, Zhang G, Lei T, Tan Y. Wound ballistics of the pig mandibular angle: a preliminary finite element analysis and experimental study. J Biomech 2010;43: 1131–7. 9. Bartlett CS. Clinical update: gunshot wound ballistics. Clin Orthop Relat Res 2003;408:28–57. ˚ . Injuries to 10. Giannou C, Baldan M, Molde A bones and joints. War surgery: working with limited resources in armed conflict and other situations of violence, vol. 2. Geneva: International Committee of the Red Cross; 2013. p. 103–68. Available at: http://www.icrc.org/ eng/resources/documents/publication/ p4105.htm (accessed 24.04.14). 11. Janzon B, Hull JB, Ryan JM. Projectile– material interactions: soft tissue and bone. In: Cooper GJ, Dudley HA, Gann DS, Little RA, Maynard RL, editors. Scientific foundations of trauma. Oxford: ButterworthHeinemann; 1997. p. 37–52. 12. Bellamy RF, Zajtchuk R. The physics and biophysics of wound ballistics. Conventional warfare: ballistic, blast, and burn injuries. Washington, DC: Walter Reed

Wound ballistics of firearm-related injuries—Part 2

13.

14.

15.

16.

17.

18.

19.

20.

21.

22.

23.

24.

25.

26.

Army Medical Center, Office of the Surgeon General; 1991. p. 107–62. Mellor SG. Characteristics of missiles injuries. In: Williams JL, editor. Rowe and Williams’ maxillofacial injuries. 2nd ed. Edinburgh: Churchill Livingstone; 1994 . p. 666–74. Mars M, Spencer RF. Penetrating injury to bone. In: Cooper GJ, Dudley HA, Gann DS, Little RA, Maynard RL, editors. Scientific foundations of trauma. Oxford: Butterworth-Heinemann; 1997. p. 63–72. Kieser J. Basic principles of biomechanics. In: Kieser J, Taylor M, Carr D, editors. Forensic biomechanics. Oxford: WileyBlackwell; 2013. p. 26. Kieser DC, Riddell R, Kieser JA, Theis JC, Swain MV. Bone micro-fracture observations from direct impact of slow velocity projectiles. J Arch Milit Med 2014;2:e15614. Available at: http://jammonline.com/?page=archives (accessed 24.04.14). Huelke DF, Darling JH. Bone fractures produced by bullets. J Forensic Sci 1964;9:461–9. Huelke DF, Buege LJ, Harger JH. Bone fractures produced by high velocity impacts. Am J Anat 1967;120:123–31. Huelke DF, Harger JH, Buege LJ, Dingman HG, Harger DR. An experimental study in bio-ballistics: femoral fractures produced by projectiles. J Biomech 1968;1:97–105. Huelke DF, Harger JH, Buege LJ, Dingman HG. An experimental study in bio-ballistics: femoral fractures produced by projectiles—II. Shaft impacts. J Biomech 1968;1:313–21. Rothschild MA. Conventional forensic medicine. In: Kneubuehl BP, Coupland RM, Rothschild MA, Thali MJ, editors. Wound ballistics: basics and applications. Berlin: Springer; 2011. p. 253–85. [Translation of the revised 3rd German edition by Rawcliffe S]. Kneubuehl BP. General wound ballistics. In: Kneubuehl BP, Coupland RM, Rothschild MA, Thali MJ, editors. Wound ballistics: basics and applications. Berlin: Springer; 2011. p. 87–161. [Translation of the revised 3rd German edition by Rawcliffe S]. Harger JH, Huelke DF. Femoral fractures produced by projectiles—the effects of mass and diameter on target damage. J Biomech 1970;3:487–93. ˚ ., Gray R. High-velocity gunshot Molde A wound through bone with low energy transfer (letter). Injury 1995;26:131. Harvey EN, McMillen JH, Butler EG, Puckett WO. Mechanism of wounding. In: Beyer JC, editor. Wound ballistics. Washington, DC: Office of the Surgeon General, Department of the Army; 1962 . p. 143–235. Kneubuehl BP. Basics. In: Kneubuehl BP, Coupland RM, Rothschild MA, Thali MJ, editors. Wound ballistics: basics and appli-

27.

28.

29.

30.

31.

32.

33.

34.

35.

36.

37.

38.

39.

40.

41.

42.

43.

cations. Berlin: Springer; 2011. p. 84–5. [Translation of the revised 3rd German edition by Rawcliffe S]. Ragsdale BD, Josselson A. Experimental gunshot fractures. J Trauma 1988;28(Suppl 1):S109–15. Ragsdale BD. Gunshot wounds: a historical perspective. Mil Med 1984;149:301– 15. Rose SC, Fujisaki CK, Moore EE. Incomplete fractures associated with penetrating trauma: etiology, appearance, and natural history. J Trauma 1988;28:106–9. Yetiser S, Kahramanyol M. High-velocity gunshot wounds to the head and neck: a review of wound ballistics. Mil Med 1998;163:346–51. Clasper JC, Hodgetts TJ. High-velocity gunshot wound through bone with low energy transfer. Injury 1994;25:264–6. Clasper JC, Hill PF, Watkins PE. Contamination of ballistic fractures: an in vitro model. Injury 2002;33:157–60. Dougherty PJ, Sherman D, Dau N, Bir C. Ballistic fractures: indirect fracture to bone. J Trauma 2011;71:1381–4. Janzon B. High energy missile trauma: a study of the mechanisms of wounding of muscle tissue. Gothenburg, Sweden: Faculty of Medicine, University of Go¨teborg; 1983. [Doctorial thesis]. Clasper J. The interaction of projectiles with tissues and the management of ballistic fractures. JR Army Med Corps 2001;147:52–61. Di Maio VJ. Gunshot wounds: practical aspects of firearms, ballistics, and forensic techniques. 2nd ed. Boca Raton: CRC Press; 1999. Betz P, Stiefel D, Hausmann R, Eisenmenger W. Fractures at the base of the skull in gunshots to the head. Forensic Sci Int 1997;86:155–61. Simpson DA, Abbott J. Pathology of injury and repair. In: David DJ, Simpson DA, editors. Craniomaxillofacial trauma. Edinburgh: Churchill Livingstone; 1995. p. 140. Beyer JC. Wound ballistics. Washington, DC: Office of the Surgeon General, Department of the Army; 1962 . p. 201. [footnote]. Rothschild MA, Kneubuehl BP. Irrtu¨mer in der wundballistik. Rechtsmedizin 2010;20: 85–90. Amato JJ, Syracuse D, Seaver Jr PR, Rich N. Bone as a secondary missile: an experimental study in the fragmenting of bone by high-velocity missiles. J Trauma 1989;29: 609–12. Kieser J. Biomechanics of bone and bony trauma. In: Kieser J, Taylor M, Carr D, editors. Forensic biomechanics. Oxford: Wiley-Blackwell; 2013. p. 54–62. Mainous EG, Sazima HJ, Stump TE, Kelly JF. Wounding agents and wounds. In: Kelly JF, editor. Management of war injuries to the jaws and related structures. Washing-

44.

45.

46.

47.

48.

49.

50.

51.

52.

53.

54.

55.

56.

57.

58.

75

ton, DC: US Government Printing Office; 1977. p. 35–44. Banks P. Gunshot wounds. In: Williams JL, editor. Rowe and Williams’ maxillofacial injuries. 2nd ed. Edinburgh: Churchill Livingstone; 1994. p. 683–713. Whitlock RI, Kendrick RW. Urban guerrilla warfare. In: Williams JL, editor. Rowe and Williams’ maxillofacial injuries. 2nd ed. Edinburgh: Churchill Livingstone; 1994 . p. 766–98. David DJ, Tan E. Massive tissue loss. In: David DJ, Simpson DA, editors. Craniomaxillofacial trauma. Edinburgh: Churchill Livingstone; 1995. p. 445–59. Kincaid B, Schmitz JP. Tissue injury and healing. Oral Maxillofac Surg Clin North Am 2005;17:241–50. Monaghan AM. Maxillofacial ballistic injuries. In: Brooks AJ, Clasper J, Midwinter MJ, Hodgetts TJ, Mahoney PF, editors. Ryan’s ballistic trauma: a practical guide. 3rd ed. London: Springer; 2011 . p. 379– 94. Stump TE. Maxillofacial injuries from high-velocity missiles: mechanism, wounding action and classification of gunshot wounds. In: Jacobs JR, editor. Maxillofacial trauma: an international perspective. New York: Praeger; 1983. p. 41–9. Dougherty PJ. Soft-tissue wound management. In: Dougherty PJ, editor. Gunshot wounds (Monograph Series 44). Rosemont, IL: AAOS; 2011. p. 37–42. Gant TD, Epstein LI. Low-velocity gunshot wounds to the maxillofacial complex. J Trauma 1979;19:674–7. Suominen E, Tukiainen E. Close-range shotgun and rifle injuries to the face. Clin Plast Surg 2001;28:323–37. McLean JN, Moore CE, Yellin SA. Gunshot wounds to the face—acute management. Facial Plast Surg 2005;21:191–8. Vayvada H, Menderes A, Yilmaz M, Mola F, Kizilkaya A, Atabey A. Management of close-range, high-energy shotgun and rifle wounds to the face. J Craniofac Surg 2005;16:794–804. Breeze J, Allanson-Bailey LS, Hunt NC, Midwinter MJ, Hepper AE, Monaghan A, et al. Surface wound mapping of battlefield occulo-facial injury. Injury 2012;43:1856– 60. Clark N, Birely B, Manson PN, Slezak S, Vander Kolk C, Robertson B, et al. Highenergy ballistic and avulsive facial injuries: classification, patterns, and an algorithm for primary reconstruction. Plast Reconstr Surg 1996;98:583–601. Ellis III E, Muniz O, Anand K. Treatment considerations for comminuted mandibular fractures. J Oral Maxillofac Surg 2003;61: 861–70. Eppley BL. Reconstruction of large hard and soft tissue loss of the face. In: Ward Booth P, Eppley BL, Schmelzeisen R, editors. Maxillofacial trauma and esthetic

76

59.

60.

61.

62.

63.

64.

65.

66.

67.

68.

69.

70.

71.

72.

73.

Stefanopoulos et al. facial reconstruction. 2nd ed. St. Louis: Elsevier Saunders; 2012. p. 368–401. Newlands SD, Samudrala S, Katzenmeyer WK. Surgical treatment of gunshot injuries to the mandible. Otolaryngol Head Neck Surg 2003;129:239–44. Tinder LE. Comparative analysis of mandibular and mid-face fractures in missile and blunt trauma: 4,015 cases. Presidio, San Francisco, CA: Letterman Army Institute of Research; 1970. Available at: http:// handle.dtic.mil/100.2/AD0713584 (accessed 24 April 2014) (approved for public release). Kassan AH, Lalloo R, Kariem G. A retrospective analysis of gunshot injuries to the maxillo-facial region. SADJ 2000;55:359– 63. Haug RH, Morgan III JP. Etiology, distribution and classification of craniomaxillofacial deformities: traumatic defects. In: Greenberg AM, Prein J, editors. Craniomaxillofacial reconstructive and corrective bone surgery: principles of internal fixation using the AO/ASIF technique. Berlin: Springer; 2002 . p. 43–8. Peleg M, Sawatari Y. Management of gunshot wounds to the mandible. J Craniofac Surg 2010;21:1252–6. Smith HW, Wheatley KK. Biomechanics of femur fractures secondary to gunshot wounds. J Trauma 1984;24:970–7. Walker RV, Frame JW. Civilian maxillofacial gunshot injuries. Int J Oral Surg 1984;13:263–77. Hollier L, Grantcharova EP, Kattash M. Facial gunshot wounds: a 4-year experience. J Oral Maxillofac Surg 2001;59: 277–82. Kihtir T, Ivatury RR, Simon RJ, Nassoura Z, Leban S. Early management of civilian gunshot wounds to the face. J Trauma 1993;35:569–75. Manson PN. Facial fractures. In: Mathes SJ, editor. Plastic surgery, 2nd ed., vol. 3. Philadelphia: Saunders Elsevier; 2006. p. 344–61. Glapa M, Kourie JF, Doll D, Degiannis E. Early management of gunshot injuries to the face in civilian practice. World J Surg 2007;31:2104–10. Peled M. Gunshot injury. In: Laskin DM, Abubaker AO, editors. Decision making in oral and maxillofacial surgery. Chicago: Quintessence; 2007. p. 88–9. Robertson B, Manson PN. The importance of serial debridement and ‘‘second-look’’ procedures in high-energy ballistic and avulsive facial injuries. Oper Tech Plast Surg 1998;5:236–45. Williams CN, Cohen M, Schultz RC. Immediate and long-term management of gunshot wounds to the lower face. Plast Reconstr Surg 1988;82:433–9. McVeigh K, Breeze J, Jeynes P, Martin T, Parmar S, Monaghan AM. Clinical strate-

74.

75.

76.

77.

78.

79.

80.

81.

82.

83.

84.

85.

86.

87.

gies in the management of complex maxillofacial injuries sustained by British military personnel. J R Army Med Corps 2010;156:110–3. Hallock GG. Self-inflicted gunshot wounds of the lower half of the face: the evolution toward early reconstruction. J Craniomaxillofac Trauma 1995;1:50–5. Vasconez HC. Management of massive bone and soft tissue defects of the midface and lower face. Probl Plast Reconstr Surg 1991;1:466–81. Motamedi MH. Primary management of maxillofacial hard and soft tissue gunshot and shrapnel injuries. J Oral Maxillofac Surg 2003;61:1390–8. Peled M, Leiser Y, Emodi O, Krausz A. Treatment protocol for high velocity/high energy gunshot injuries to the face. Craniomaxillofac Trauma Reconstr 2012;5: 31–40. Loos MS, Freeman BG, Lorenzetti A. Zone of injury: a critical review of the literature. Ann Plast Surg 2010;65:573–7. Powers DB, Delo RI. Maxillofacial ballistic and missile injuries. In: Fonseca RJ, Walker RV, Barber HD, Powers MP, Frost DE, editors. Oral and maxillofacial trauma. 4th ed. St. Louis: Elsevier Saunders; 2013. p. 696–716. Haywood I. Immediate management. In: Williams JL, editor. Rowe and Williams’ maxillofacial injuries. 2nd ed. Edinburgh: Churchill Livingstone; 1994. p. 675. Johnson J, Markiewicz MR, Bell RB, Potter BE, Dierks EJ. Gun orientation in selfgunshot inflicted craniomaxillofacial wounds: risk factors associated with fatality. Int J Oral Maxillofac Surg 2012;41: 895–901. Manson PN. Dimensional analysis of the facial skeleton: avoiding complications in the management of facial fractures by improved organization of treatment based on CT scans. Probl Plast Reconstr Surg 1991;1:213–37. Holland IS, McMahon JD, Koppel DA, Devlin MF, Moos KF. Maxillary and panfacial fractures. In: Ward Booth P, Eppley BL, Schmelzeisen R, editors. Maxillofacial trauma and esthetic facial reconstruction. 2nd ed. St. Louis: Elsevier Saunders; 2012. p. 228–51. Va´sconez HC, Shockley ME, Luce E. Highenergy gunshot wounds to the face. Ann Plast Surg 1996;36:18–25. Dolin J, Scalea T, Mannor L, Sclafani S, Trooskin S. The management of gunshot wounds to the face. J Trauma 1992;33: 508–15. Be´nateau H, Riscala S, Labbe´ D, Compe`re JF. Le´sions faciales par arme a` feu. Rev Stomatol Chir Maxillofac 2001;102:129–32. Demetriades D, Chahwan S, Gomez H, Falabella A, Velmahos G, Yamashita D. Initial evaluation and management of gun-

88.

89.

90.

91.

92.

93.

94.

95.

96.

97.

98.

99.

100.

101.

102.

shot wounds to the face. J Trauma 1998;45:39–41. Calhoun KH, Li S, Clark WD, Stiernberg CM, Quinn Jr FB. Surgical care of submental gunshot wounds. Arch Otolaryngol Head Neck Surg 1988;114:513–9. Orthopoulos G, Sideris A, Velmahos E, Troulis M. Gunshot wounds to the face: emergency interventions and outcomes. World J Surg 2013;37:2348–52. Kummoona R, Muna AM. Evaluation of immediate phase of management of missile injuries affecting maxillofacial region in Iraq. J Craniofac Surg 2006;17:217–23. Futran ND, Farwell DG, Smith RB, Johnson PE, Funk GF. Definitive management of severe facial trauma utilizing free tissue transfer. Otolaryngol Head Neck Surg 2005;132:75–85. Lee D, Nash M, Turk J, Har-El G. Lowvelocity gunshot wounds to the paranasal sinuses. Otolaryngol Head Neck Surg 1997;116:372–8. Spiessl B. Gunshot fractures. Internal fixation of the mandible: a manual of AO/ ASIF principles. Berlin: Springer; 1989. p. 262–5. Stuehmer C, Essig H, Schramm A, Ru¨cker M, Eckardt A, Gellrich NC. Intraoperative navigation assisted reconstruction of a maxillo-facial gunshot wound. Oral Maxillofac Surg 2008;12:199–203. Dean NR, McKinney SM, Wax MK, Louis PJ, Rosenthal EL. Free flap reconstruction of self-inflicted submental gunshot wounds. Craniomaxillofac Trauma Reconstr 2011;4:25–34. Henriksson TG. Close range blasts toward the maxillofacial region in attempted suicide. Scand J Plast Reconstr Hand Surg 1990;24:81–6. Simpson DA, McLean AJ. Mechanisms of injury. In: David DJ, Simpson DA, editors. Craniomaxillofacial trauma. Edinburgh: Churchill Livingstone; 1995. p. 101–17. Fackler ML. Re: high-energy gunshot wounds to the face. Ann Plast Surg 1997;38:82. ˚ . MaxilloGiannou C, Baldan M, Molde A facial injuries. War surgery: working with limited resources in armed conflict and other situations of violence, vol. 2. Geneva: International Committee of the Red Cross; 2013. p. 283–307. Available at: http://www.icrc.org/eng/resources/documents/publication/ p4105.htm (accessed 24 April 2014). May M, Cutchavaree A, Chadaratana P, West J. Mandibular fractures from civilian gunshot wounds: a study of 20 cases. Laryngoscope 1973;83:969–73. Clarkson PW, Walker FA. Gun-shot wounds of the face and jaws. In: Rowe NL, Killey HC, editors. Fractures of the facial skeleton. 2nd ed. Edinburgh: Livingstone; 1968. p. 471. Gibbons AJ, Breeze A. The face of war: the initial management of modern battlefield

Wound ballistics of firearm-related injuries—Part 2

103.

104.

105.

106.

107.

108.

109. 110.

111.

112.

113.

114.

115.

116.

117.

ballistic facial injuries. J Milit Veter Health 2011;19:15–8. Ryan JM, Rich NM, Burris DG, Ochsner MG. Biophysics and pathophysiology of penetrating injury. In: Ryan JM, Rich NM, Dale RF, Morgans BT, Cooper GJ, editors. Ballistic trauma: clinical relevance in peace and war. London: Arnold; 1997. p. 36. Petersen K, Hayes DK, Blice JP, Hale RG. Prevention and management of infections associated with combat-related head and neck injuries. J Trauma 2008;64(Suppl): S265–76. Tan Y, Zhou S, Liu Y, Liu B, Li Z. Smallvessel pathology and anastomosis following maxillofacial firearm wounds: an experimental study. J Oral Maxillofac Surg 1991;49:348–52. Zhou S, Lei D, Liu Y, Tan Y, Gu X. Experimental study on firearm wound in maxillofacial region. Chin Med J (Engl) 1998;111:114–7. Lai X, Liu Y, Wang J, Li S, Chen L, Guan Z. Injury to vascular endothelial cells and the change of plasma endothelin level in dogs with gunshot wounds. J Trauma 1996;3(Suppl): S60–2. Di Maio VJ. Wounds from civilian and military centerfire rifles. Clin Lab Med 1998;18:189–201. Di Maio VJ. Wounds caused by centerfire rifles. Clin Lab Med 1983;3:257–71. Treib J, Haass A, Grauer MT. High-velocity bullet causing indirect trauma to the brain and symptomatic epilepsy. Mil Med 1996;161:61–4. Pilcher R. Management of missile wounds of the maxillofacial region during the 20th century. Injury 1996;27:81–8. Tan Y, Zhou S, Liu Y, Li Z. A gross and microscopic study of cerebral injuries accompanying maxillofacial high-velocity projectile wounding in dogs. J Oral Maxillofac Surg 1998;56:345–8. Courtney A, Courtney M. Links between traumatic brain injury and ballistic pressure waves originating in the thoracic cavity and extremities. Brain Inj 2007;21: 657–62. May M, West JW, Heeneman H, Gowda CK, Ogura JH. Shotgun wounds to the head and neck. Arch Otolaryngol 1973;98:373– 6. Shepard GH. High-energy, low-velocity close range shotgun wounds. J Trauma 1980;20:1065–7. Harruff RC. Comparison of contact shotgun wounds of the head produced by different gauge shotguns. J Forensic Sci 1995;40: 801–4. Siberchicot F, Pinsolle J, Majoufre C, Ballanger A, Gomez D, Caix P. Traumatismes faciaux par arme de chasse a` canon lisse: analyse d’une se´rie de 165 cas et re´e´valuation du traitement primaire. Ann Chir Plast Esthe´t 1998;43:132–40.

118. Yuksel F, Celikoz B, Ergun O, Peker F, Ac¸ikel C, Ebrinc S. Management of maxillofacial problems in self-inflicted rifle wounds. Ann Plast Surg 2004;53:111–7. ¸ ankayali R, Songu¨r E. 119. Alper M, Totan S, C Gunshot wounds of the face in attempted suicide patients. J Oral Maxillofac Surg 1998;56:930–4. 120. Stuehmer C, Blum KS, Kokelueller H, Tavassol F, Bormann KH, Gellrich NC, et al. Influence of different types of guns, projectiles, and propellants on patterns of injury to the viscerocranium. J Oral Maxillofac Surg 2009;67:775–81. 121. Coupland RM. Wound ballistics and surgery. In: Kneubuehl BP, Coupland RM, Rothschild MA, Thali MJ, editors. Wound ballistics: basics and applications. Berlin: Springer; 2011. p. 305–20. [Translation of the revised 3rd German edition by Rawcliffe S]. 122. Bellamy RF, Zajtchuk R. The management of ballistic wounds of soft tissue. Conventional warfare: ballistic, blast, and burn injuries. Washington, DC: Walter Reed Army Medical Center, Office of the Surgeon General; 1991. p. 163–220. 123. Dahlgren B, Berlin R, Janzon B, Nordstro¨m G, Nylo¨f U, Rybeck B, et al. The extent of muscle tissue damage following missile trauma one, six and twelve hours after the infliction of trauma, studied by the current method of debridement. Acta Chir Scand Suppl 1979;498:137–44. 124. Jussila J, Kjellstro¨m BT, Leppa¨niemi A. Ballistic variables and tissue devitalisation in penetrating injury—establishing relationship through meta-analysis of a number of pig tests. Injury 2005;36: 282–92. 125. Hale RG, Hayes DK, Orloff G, Peterson K, Powers DB, Mahadevan S. Maxillofacial and neck trauma. In: Savitsky E, Eastridge B, editors. Combat casualty care: lessons learned from OEF and OIF. Falls Church, VA: Office of the Surgeon General, Department of the Army, United States of America; 2012 . p. 225–97. Available at: http:// www.cs.amedd.army.mil/borden/book/ccc/ UCLAchp6.pdf (accessed 24.04.14). 126. Robertson BC, Manson PN. High-energy ballistic and avulsive injuries. A management protocol for the next millennium. Surg Clin North Am 1999;79: 1489–502. 127. Dorafshar AH, Rodriguez ED. Management of avulsive gunshot wounds to the face. In: Bagheri SC, Bell RB, Khan HA, editors. Current therapy in oral and maxillofacial surgery. St. Louis: Elsevier Saunders; 2012. p. 361–5. 128. Sinn DP. Facial gunshot wounds: a 4-year experience. J Oral Maxillofac Surg 2001;59:282. (discussion). 129. Rodriguez ED, Martin M, BluebondLangner R, Khalifeh M, Singh N, Manson PN. Microsurgical reconstruction of post-

130.

131.

132.

133.

134.

135.

136.

137.

138.

139.

140.

141.

142.

143.

77

traumatic high-energy maxillary defects: establishing the effectiveness of early reconstruction. Plast Reconstr Surg 2007;120(Suppl 2):103S–17S. Powers DB, Will MJ, Bourgeois SL, Hatt HD. Maxillofacial trauma treatment protocol. Oral Maxillofac Surg Clin North Am 2005;17:341–55. Futran ND. Maxillofacial trauma reconstruction. Facial Plast Surg Clin North Am 2009;17:239–51. Tikka S. The contamination of missile wounds with special reference to early antimicrobial therapy. Acta Chir Scand Suppl 1982;508:281–7. Mellor SG, Cooper GJ, Bowyer GW. Efficacy of delayed administration of benzylpenicillin in the control of infection in penetrating soft tissue injuries in war. J Trauma 1996;40(Suppl):S128–34. Jiang H, Liu Y, Zhang M. The experimental observation on characteristics of soft tissues infection in maxillofacial region wounded by high velocity missile. West China J Stomatol 1997;15:13–5. (in Chinese). Tian HM, Deng GG, Huang MJ, Tian FG, Su¨ang GY, Liu YG. Quantitative bacteriological study of the wound track. J Trauma 1988;28(Suppl 1):S215–6. Hospenthal DR, Murray CK, Andersen RC, Bell RB, Calhoun JH, Cancio LC, et al. Guidelines for the prevention of infections associated with combat-related injuries: 2011 update. J Trauma 2011;71(Suppl 2):S210–34. Gruss JS, Antonyshyn O, Phillips JH. Early definitive bone and soft-tissue reconstruction of major gunshot wounds of the face. Plast Reconstr Surg 1991;87:436–50. Herford AS. Early repair of avulsive facial wounds secondary to trauma using interpolation flaps. J Oral Maxillofac Surg 2004;62:959–65. Antonyshyn OM, Paletz JL, Wilson KL. Reconstruction of composite facial defects: the combined application of multiple reconstructive modalities. Can J Surg 1993;36:441–52. Doctor VS, Farwell DG. Gunshot wounds to the head and neck. Curr Opin Otolaryngol Head Neck Surg 2007;15: 213–8. Fernandes R. Fibula free flap in mandibular reconstruction. Atlas Oral Maxillofac Surg Clin North Am 2006;14:143–50. Fernandes R. The anterolateral thigh flap in mandibular reconstruction. Atlas Oral Maxillofac Surg Clin North Am 2006;14: 185–9. Prein J, Hammer B. Reconstruction of extensive anterior defects of the mandible. In: Greenberg AM, Prein J, editors. Craniomaxillofacial reconstructive and corrective bone surgery: principles of internal fixation using the AO/ASIF technique. Berlin: Springer; 2002. p. 414–8.

78

Stefanopoulos et al.

144. Stannard JP, Singanamala N, Volgas DA. Fix and flap in the era of vacuum suction devices: what do we know in terms of evidence based medicine? Injury 2010;41: 780–6.

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