Accidentally lodged airgun pellet in maxilla during childhood play retrieved surgically after a decade

Abstract

Non-powder firearm-related injuries to the head and neck carry the potential risk of significant morbidity and mortality. Such penetrating injuries tend to be under-reported and trivialised especially in children. Air gun pellet injury may cause damage to both soft tissue and bone. Some metals, when embedded in body tissue, can evoke a foreign body reaction or release toxins over time. It therefore becomes imperative to retrieve these pellets. We present one such case of accidental lodgement of airgun pellet in the right maxilla of a 12-year-old boy during childhood play with an airgun which went unnoticed at that time and was surgically retrieved after a decade. The patient had not suffered from any neurosensory deficit.

Background

Maxillofacial trauma can occur as a result of motor vehicle accidents, fall from height, assaults, sports and gunshot injuries. Gunshot wounds can cause extensive damage to both hard and soft tissues of the maxillofacial complex.

The severity of such injuries depends on various factors such as the calibre of the weapon; the shape, size and velocity of the shrapnel; the distance from which the patient has been shot and the jagged edges of the fragment.

Gunshot wounds are classified as penetrative (a wound accompanied by disruption of the body surface that extends into the underlying tissue or into bony cavity), avulsive (a wound in which a portion of skin and other soft tissues is torn/detached) and perforative (an injury in which an object enters the body and passes all the way through).¹

Non-powder firearms such as Ball bearing and pellet guns use compressed air or gas to propel steel or lead ball pellets. The complications of firearm-related injuries are well recognised; however, injuries caused by non-powder firearms tend to be under-reported and therefore undertreated.²

These relatively low energy missiles have a direct effect on the tissues in the maxillofacial region causing lacerations and crushing within the missile tract. There are vital neurovascular bundles and major vessels which are at risk and require an early diagnosis and immediate management.³

We present a case of air gun pellet injury to the right maxilla which got diagnosed after a decade and was unnoticed at the time of injury.

Case presentation

A 22-year-old male reported with a foreign body sensation in the upper right anterior tooth region. Patient’s medical and dental history were unremarkable. A detailed case history was recorded including the patient’s family background. After much deliberation, it was revealed that the patient’s uncle was a police officer. The patient recalled one incident during childhood wherein he and his uncle’s son were playing unsupervised with an airgun. Suddenly, the uncle’s son accidentally pushed the button of airgun and shot it towards his face. He sustained a minor injury on his face and applied an ice pack for the slight bleeding himself. Later on, after a few days the injured wound got healed uneventfully. He concealed the incident from his parents due to fear of scolding.

On extraoral examination, there was presence of a nearly invisible scar below ala of right nostril. No major facial asymmetry was noted. Extraoral palpation in that region elicited slight pain and was indicative of the presence of a stony hard mass. The lymph nodes were non-tender and non-palpable.

Intraoral examination revealed a slight bulge above the apical level of upper right canine and lateral incisor with a slight bluish hue in the overlying mucosa. A hard material could be palpated with moderate pain (figure 1A, B).

Figure 1.

Pre operative: (A) frontal profile showing inconspicuous mark on right nasolabial fold region, (B) intraoral view showing bluish hue of air gun pellet in the upper right canine vestibular region, (C) orthopantomogram showing small metallic air gun pellet embedded near apical area of 12 and 13, (D) axial view of CT scan showing gun pellet dimensions, (E) three-dimensional reconstruction showing impacted air gun pellet near nasal floor.

Investigations

An orthopantomogram revealed a radiopacity above the apices of the upper right canine and lateral incisor suggestive of a metallic foreign object. A CT scan was further done to accurately assess the size, shape of the metallic object and the penetration depth of the object in the maxillofacial region. An axial sectional image of the CT scan displayed a foreign body impacted in the right maxilla. The shape of the foreign object was consistent with that of an airgun pellet. The pellet was 11.8 mm by 7.7 mm in size (figure 1C–E). Toxicolological blood analysis was done and the serum lead level was found to be within normal limits.

Treatment

After clinicoradiological correlation and basic blood investigations, surgical retrieval of the foreign object was planned under local anaesthesia. Patient was painted and draped under all aseptic conditions. Lidocaine hydrochloride with epinephrine (1:200 000) was administered. Semilunar incision was placed. The mucoperiosteal flap was raised so as to expose the foreign object. Bone guttering was done around the metallic object. A metallic object lodged in the maxillary bone was retrieved followed by copious irrigation of the surgical site with an antiseptic solution and normal saline. Closure was done with 3–0 silk suture, reverse-cutting needle followed by placement of a moist pressure pack. Patient was prescribed an antibiotic course for a period of 5 days along with the necessary analgesic. The sutures were removed on the seventh postoperative day (figure 2A–C).

Figure 2.

Intraoperative: (A) exposed air gun pellet, (B) removal of embedded air gun pellet, (C) retrieved diabolo air gun pellet, (D) postoperative: orthopantomogram showing regenerated osseous defect, (E) intraoral view showing satisfactory healed soft tissue.

Outcome and follow-up

Postoperative orthopantomogram showed regenerated osseous defect and intraoral soft-tissue healing was found to be satisfactory (figure 2D, E).

Discussion

Air guns were used in the Napoleonic wars in the late 17th and early 18th centuries. They were known as wind chambers and used an air reservoir which was connected to a cannon barrel.⁴

Most of the air gun pellet injuries are known to occur in children. In a retrospective study conducted by Bratton et al on 101 children, it was found that 81% of them were males with a median range of 10.9 years.⁵ In the present case, the patient was a 12-year-old boy who was shot accidentally with an air gun during childhood play. The incident went unnoticed at the time of injury and the patient reported after a decade with a foreign body sensation.

As proposed by many authors, before any surgical intervention is done, radiological investigations must be carried out. Plain radiographs, CT and MRI scans can be done to give an idea about the nature and extent of injury. MRI scans can reveal non-metallic foreign bodies. Conventional radiographs in two planes can be taken along with radiopaque markers to allow for fast, intraoperative localisation of radiopaque foreign bodies present within the soft tissue. Fluoroscopy can also be used to localise the objects intraoperatively.³ In our case, orthopantomogram and CT face with three-dimensional reconstruction were opted to assess the size, shape of the metallic object and depth of penetrated gun pellet in the maxillofacial region.

Management of gunshot injury to the head and neck region requires a thorough risk–benefit analysis. Many authors have advocated a non-operative approach for cases with minimal risk to the neurovascular apparatus. However, some absolute indications for surgical management are profuse bleeding, expanding or pulsatile haematoma, respiratory compromise or violation of the trachea, oesophagus or other great vessels.² Immediate surgical exploration is warranted when there is active bleeding and the diagnostic work should be reserved only for the patients who are haemodynamically stable. Blind removal of the bullets or other objects may cause life-threatening haemorrhage as the vessels involved might be tamponaded by the foreign bodies.³ For our case, we preferred surgical retrieval of the air gun pellet to address the patient’s problem of foreign body sensation and there was no vital structure or any great vessel in the vicinity.

The typical projectile that is used in the rifled airguns is the lead diabolo pellet which is a wasp waisted pellet. It is open at the base with a variety of head types. The flared tail is designed so as to improve the directional stability. These airguns can generate muzzle velocities of 350 feet/s or more. High energy missiles are those in which the object travels at a speed in excess of 2000 feet/s. Damage on the target is inflicted by these high energy missiles by the processes of shock wave, temporary and permanent cavitation. Low energy missile injuries occur at velocities less than 1500 feet/s producing direct effect on tissues including lacerations and crushing within the missile tract rather than temporary cavitation.⁶ In our case too, the airgun pellet was a lead diabolo type measuring approximately 11.8 mm by 7.7 mm in size. Axial section of CT scan revealed that the penetration of the air gun pellet was halfway through the maxilla indicating a low energy missile injury.

Retained pellets in the body can evoke a foreign body reaction. In case the metal of the pellet is inert in nature, it may be eventually walled off with a fibrous capsule surrounding it. Airgun pellets generally consist of 95% lead, 2.5% tin and 2.5% antimony. Bowen and Magauran reported six cases of ocular injuries with retained airgun pellets and observed raised serum levels of lead. Lead from the retained airgun pellet can cause lead poisoning or plumbism. This condition is characterised by an array of non-specific symptoms such as anorexia, vomiting, abdominal pain, constipation and weight loss. In severe cases, it may result in acute encephalopathy, stupor, lethargy, coma and convulsions. Chronic exposure to low levels of lead may result in learning deficits, behavioural changes, poor weight gain and short stature.⁷ Our patient did not present with any symptoms of lead intoxication. Toxicolological blood analysis showed no increased blood lead level.

In the craniomaxillofacial complex, airgun pellet injuries to the eyeball can result in loss of vision, corneal tears and may even require the exenteration of the eyeball. If the pellet enters the cranium, it may lead to catastrophic intracranial bleeding, meningitis, cerebrospinal fluid leakage, brain abscess, formation of carotid-cavernous sinus fistula and traumatic aneurysm. In the maxillofacial region, the pellets may be lodged in the paranasal sinuses or the jawbones.⁷ In our case, the air gun pellet was lodged near the maxillary sinus floor and there was no involvement of vital structures.

Kuhnel et al reported a case in which the patient developed oral cancer in close relation to the retained pellet in the maxillary antrum for 50 years suggesting that the lead released from the airgun pellet might have contributed to the malignant transformation even though the direct link between the two has not been proven. Therefore, the long-term effects of lead containing pellets after internalisation in various body cavities should not be underestimated.⁸ No carcinomatous changes were noted in our case.

There is ambiguity in literature whether to surgically remove the airgun pellets or to leave them in situ. Minimal invasive surgery techniques such as endoscopy have drastically reduced the surgical stress. Delayed embolisation from the primary site of pellet lodgement have been reported in many cases resulting in severe secondary damage and even death of patients. Before any surgical intervention is attempted to remove the embedded pellet, an accurate anatomic localisation of the foreign object is a must to prevent any inadvertent damage to the vital structures.⁹

Patient’s perspective.

I came to this hospital with the complaint of a foreign body sensation in my upper front tooth region. This sensation had been bothersome since many years especially while eating and shaving the moustache. After surgical removal of the pellet, I feel completely at ease.

Learning points.

• Airgun pellets may act as a source of infection and cause other complications by damaging blood vessels and surrounding vital structures.

• The long-term effects of retained bullets should not be underestimated as lead intoxication and malignant transformation have been reported.

• The decision of surgical exploration and retrieval versus conservative management requires thorough risk–benefit analysis and should be based on case-dependent factors.

• Airgun pellet injuries are associated with significant risk of mortality and morbidity. The emergency personnel and doctors must be aware that such injuries can be fatal and should therefore not be trivialised.

• Strict legislative laws should be enforced and the general public should be educated regarding its potential hazards so as to prevent or minimise the risk of injuries.

Ethics statements

Patient consent for publication

Consent obtained directly from patient(s)