my seminar discuss the ballistic science of guns, and how wounds occure and the steps of management

1. Gunshot
wounds
By ;
Dr.Mohamed Rahil Ali
4th stage maxillofacial board 2013

2. History
The gunpowder was first discovered by Chinese and
transmitted to Europe around the thirteenth century
It quickly followed by the development of projectile
weapons based on its explosive Properties
The first recorded use of a cannon was by
Edward III against the Scots in 1327
small arms carried by one or two soldiers
began appearing in the fourteenth century

3.  GSWs are the second most source of injury and death , after motor
vehicle accidents .
 The majority of civilian firearm injuries are sustained from handguns
(86%), followed by shotguns (8%) and rifles (5%).
 40% involved the frontal bone and cranium, 9% involved
the orbits, 14% involved the maxilla , 13% involved the
mandible, and 24% involved multiple sites.
 Shotgun injuries most commonly involved the mandible followed by
the maxilla and zygoma Then orbits and nasal bones .
 36% 0f patients die following admission. All of the deaths were
secondary to injuries to the chest, abdomen,or brain. There is small
percentage of deaths associated with isolated facial injuries
Demographics

4. Ballistics
 Ballistics is the science of projectile motion.
 The potential problems of a wound caused by a
projectile can be better anticipated if one has some
knowledge of the weapon and projectile type that
cause the wound.
 Ballistic science typically divided into three stages :
o Internal ballistics
o External ballistics
o Terminal ballistics

5. Internal (or interior) ballistics
 describes the forces that apply to
a projectile from the time the
propellant is ignited to the time
the projectile leaves the barrel .
 An important consideration is
barrel length , longer barrels
(rifles) allow the force of the
propellant to act on the projectile
longer and generate higher
velocities than do shorter-
barreled weapons. In addition, a
longer barrel serves to stabilize
the bullet over longer distances.

6.  Most handguns and rifles have barrels
with internal grooves referred to as
rifling , This keeps the projectile stable in
flight over longer distances

7. External ballistics
 refers to forces that act on
the bullet in flight.
The primary factors that
govern external ballistics
are the weight and shape of
the bullet .

8. Terminal ballistics
is the study of bullet
behavior once it impacts the
target .
 The science of termal
ballistics is most important
to the surgeon and is the
most common source of
controversy when discussing
ballistic wounding .

9. Factors
which affect
the degree
of injury
Velocity of
the bullet
Mass of
the bullet
Size of
the bullet
Drag and
retardation
Composition
and shape
of the bullet
Extent of
the
cavitation
Extent of
deviation
(yaw) of
the bullet

10. Velocity and Mass of the bullet
 kinetic energy has been used as the basis to explain wounds caused
by the gunshot
KE = mv2
where KE is kinetic energy , ( m ) is the mass of the projectile, and ( v )
is the velocity of the projectile .
 Wounding power is typically related to the amount of kinetic energy
transferred to the target: P = m(V impact – V exit)2 where P is
power, m is mass of the projectile,and V is velocity
 Based on these formulas, the velocity of a projectile considered
more important than its mass in wounding power .
 Considering a typically sized projectile velocity of approximately 50
m/s is required to penetrate the skin, and a velocity of around 65
m/s will fracture the bone .

11. Composition and shape of the bullet
 earliest projectile was a stone or
lead ball .
 Over time the projectile evolved to
the conical-shape .
 full-metal jacket with exposed lead
tips to expand on impact for
maximum tissue destruction
 hollow points handgun bullets
evolved to compensate for their low
velocity which is difficult to expand
in tissue.
 some bullets are designed to explode
when impact .

13. Extent of deviation of the bullet
 all projectiles become unstable in flight because
of the center of gravity lies behind the center of
resistance of the bullet (bullet tip )
 yaw ; Oscillation of the bullet around there
long axis
 tumble ; rotation of the bullet around there
center .
 when the projectile encounter a denser
substance such as tissue, it will starts tumbling
lead to Increase in their profiles causes more
tissue wounding because it presents a larger
surface area , Increase in the rate of kinetic
energy dissipation and Increased probability of
fragmentation .

14. Drag and retardation

15. low velocity
• ( < 350 m/s )
Intermediate velocity
• (350–600 m/s)
high velocity
• (> 600 m/s)
Classification of gunshot according to
velocity

16. Components of projectile wounding:
 Penetration : a bullet must
penetrate to a sufficient depth
to cause damage.
 Permanent cavity : the space
that results from direct tissue
disruption and destruction.
 Temporary cavity : results in
stretching Of elastic tissues .
 Fragmentation : missile
fragment or secondary
fragments such as clothing or
bone.

17. Fragments
• Primary
• Secondary
Bullets
• Handguns
• Rifles
• Shotguns
Types of the Missiles

18. Also called pistols and revolvers
Low or intermediate velocity
Characterised by short barrel
Handguns

19. Rifles intermediate to high velocity
 Charectarised by long barrel so the bullet has
more time to accelerate

20. Features of high velocity missile:
1) Temporary cavity :
 results from stretching Of elastic
tissues
 most tissues has an elastic nature and
ability to recover from stretching except
some tissues such as brain ,liver,spleen
 damage from temporary cavitation is
not so important In the face : air
cavities mitigate the effect of cavitation

21. 2) Stress wave :
 Precedes the cavitation phenomena
 Not like the shock wave it does not have
the characteristic or velocity of the shock
wave produced by an explosion
 Transmitted through fluid filled
structures like blood vessels causing
endothelial damage and thrombosis
 Fracture of bone away from the wound
tract is due to stress wave rather than
cavitation
 For maxillofacial region : the stress wave
is more important than cavitation .

23. Shotguns
 low to intermediate velocity
 The charge from shotgun consist of
several hundred lead pellets
 Because of their unique ballistic
profile,shotgun injuries are often
classified based on the distance to
the target …..

24. • Type I < 5 m ;
• the pellets strike the target as a single mass,
• resulting in massive kinetic energy transfer and
tissue avulsion
• high mortality rate (85–90%)
• Type II injuries (5–12 m) ;
• usually result in much less tissue destruction.
• there is significant dispersal of the pellets and
loss of energy.
• Penetration may occur through deep fascia,
but fractures are rare. Ocular injuries can occur
as well as embolization of lead pellets,
• mortality rate (15–20%)
• Type III injuries > 12 m ;
• usually only the skin is penetrated
• mortality is rare (0–5%)

25. Fragments
shell , grenade , bomb

27. Bomb blast injuries :
•Burns from the flash of explosion .
•Blast wave ( shock wave ) of the explosion
•Direct injury
•Indirect violence
Blast wave of the explosion :
1)positive phase: very high pressure travelling
faster than the speed of air last for few milliseconds
2)negative phase : low pressure of longer duration
Also the blast wave ( shock wave ) has “ spalling “
effect when pass from one medium to another of
less density which cause the medium to spall
“fragments “
So the shock wave damage in three ways :
• Hydrostatic pressure of the shock
( positive phase )
• Dynamic pressure of the shock which follow
the hydrostatic pressure behind it ( negative
phase ).
• Spalling effect

31. Type of missile wounds :
• Nonpenetrating : grazing
or blast wound
• Penetrating : low impact
velocity ,bullet does not exit
• Perforating : high velocity
, bullet in and out
• Avulsive : massive
wounds with avulsion and
loss of tissues .

33. Management of gunshot wounds :
Late phase
soft tissue and bone reconstruction
Intermediate phase
Diet and feeding Oral hygiene Control of infection
Immediate management
primary survey
(A,B,C,D,E )
Secondary survey primary surgery

35. airway
• Loss of the airway is the most likely cause of death in
an isolated GSW to the face
• Immediately clear the lumen of the airway
• Maintain airway patency by three methods :
1. Gravity
2. Endotaracheal intubation
3. Upper airway bypass

36. Gravity
• Patient placed prone with his
forehead suspended so that
the tongue and mandible may
forwords and any debris
,blood,vomit will fall out and
thus preventing inhalation
• If there is reduction in the level
of neurological response
,placing the patient in recovery
position may be adequate but
with repeated suction of the
lumen
• In nonconscious patient oral
airway can be used

37. Endotaracheal intubation
• cuff tube inserted either by
oral or nasal route
• It is difficult to be placed in
patient with missile head and
neck injury because patient
usually conscious ,highly
distressed and hypoxic and so
not tolerated it

38. Upper airway bypass
 Used when other techniques
failed
 Include two procedures ;
1. Cricothyroidotomy
2. tracheostomy

39. Hemorrhage Control
 Initial control of hemorrhage in the emergency department center is
by direct pressure and packing.
 Blind clamping should be avoided because of the attendant risk of
damage to other structures .
 Standard methods for epistaxis control such as Foley catheters or
specially designed balloon catheters will control most midface
bleeding
 In cases of mandible fractures,temporary reduction of the fracture
may be required.
 Indications for angiography include expanding hematoma and
bleeding that persists despite local measures.
 Lacerations of the internal jugular artery are best controlled with
ligation or repair

40. Primary surgery
A)Debridment of the wound :
 wound should heavily irrigated with normal saline
and all foreign bodies removed as it is visible .
antiseptic solution such as 1% cetrimide can be used
for cleaning the wound .
 Small completely detached pieces of bone better to
be removed
 all pieces with any viable soft tissue attachment
should be conserved
B)Management of involved teeth :
o Teeth remote to fracture tend to fracture
transversely below the gingiva ( in contrast to
maxilla )
o all invovled and broken teeth should be removed
unless used for fixation and then should be
removed after fixation completed because it will be
source of infection

41. C)Reduction and Fixation :
 Closed reduction
 Open reduction
D)Closure of mucosa and skin
 Primary suture within 24 hr. give best aesthetic result
 Delayed wounds or contaminated, managed by packing and delayed
suturing
 In high velocity injury Serial surgical debridement” second-look
procedures”, at 24-to 48 hours intervals which reopen the soft tissue to
define additional areas of soft tissue necrosis, drain hematoma or
developing fluid collections, and ensure bone integrity.
 Closure Should be watertightl except in area selected for through –and
through drainage
 Closure of palatal defect may be extremely difficult and in this situation
better to be packed .

42. E)Drainage :
 All shotgun wounds of the mandible should be drained and it is
better to be placed in several places
 Where ever possible , placed away from suture lines
 In contaminated comminuted fracture the drain better be (through
–and through ) to facilitate irrigation
 Removal of the drain depend on the amount of discharge on the
dressing which should be changed at least once daily
 In general drain should be removed after progressive shortening
within the first 10 postoperative days .

43. management of Skin loss
o if skin loss (< 2 cm) it should be
reconstructed by undermining
o If more ( > 2 cm ) it managed by :
• Dressing to promot epithelialisation
• Covered by split skin graft
• Transposed flap
• Free flap

44. Contamination
 The projectiles from firearms are not sterile , The heat generated by
the discharge of the propellant as well as the friction between the
bullet and barrel is not sufficient to sterilize the bullet.
 Contamination can occur from the bullet and also from skin flora and
foreign bodies (clothing) carried into the wound ,and wounds in
which the bullet traverses the aerodigestive tract or paranasal
sinuses are at particular risk .
 Prophylactic coverage with broad-spectrum antibiotics, typically a
second-generation cephalosporin, and tetanus prophylaxis,should be
initiated in all gunshot wounds.
 Lead toxicity may occure but it is a rare complication

45. Management of foreign bodies within the tissues
 Evaluation of the risk of removal
 Small fragments may not be possible to removed all
 Larger fragments should be removed if :
a. Pain
b. Tendernes
c. Deformity
d. Infection
e. brass- or copper-jacketed bullets that are in close
proximity to central or major peripheral nerves because
of potential neurotoxicity

46. Penetrating injury of the neck
Management strategies for penetrating
neck injuries are typically based on the
zone(s) Involved
Zone I ; from the clavicles to the cricoid
cartilage
Zone II ; from the cricoid cartilage to
the angle of the mandible .
Zone III ; from the skull base to the
angle of the mandible

47. Signs of
tracheal injury
hoarsenes
stridors
subcutaneous
emphysema
dysphonia, or
hemoptysis
signs of
vascular injury
expanding
hematoma
neurologic
deficit
Penetrating injury to the neck that need urgent
management

48. Intermediate care :
• Diet and feeding
• Liquid diet
• Nasogastric tube can be used in extensive injury
• When there is loss of oral sphenicter saliva shield made of acrylic or silicon can be used
• gastrostomy if longterm bypass of the oral cavity is necessary
• Oral hygiene
• Mouth wash with antiseptic solution (chlorhexidine )
• Active irrigation with 4% sodium bicarbonate at least once daily
• Brashing by soft tooth brush
• 1% hydrocortisone ointment applied regularly to the lip
• Control of infection
• Prophylactic antibiotic to prevent infection especially meningitis and pulmonary infection
• Infection of fracture site : controled by intermediate surgery to remove teeth or sequestra
with drainage of pus if present and do culture and sensetivety test to advocate the
appropreiat antibiotic
• Early mobilisation and physiotherapy to prevent thrombophlebitis

49. Secondary or late reconstruction treatment :
 It is difficult to restore function and appearance in the
secondary phase so every effort is made to minimise the
residual defect during the initial surgical management
 delayed reconstruction in gunshot wounds that resulted from
suicide attempts

50. References ;
Rowe and williams maxillofacial injurries
 PETERSON'S PRINCIPLES OF ORAL AND MAXILLOFACIAL
SURGERY
Second Edition
 Articles from internet

51. Stop the bullet , kill the gun

52. Love your enemy
and do well to the
people who hate you
Prophet issa