A 26-year-old man presented to the emergency department with a retained canine tooth embedded in his distal forearm following a stray dog attack, according to a case report published in Open Journal of Radiology. The patient sustained multiple lacerations during the incident, including 1 to 2 cm wounds on the volar and dorsal aspects of the left distal forearm and a 6 cm laceration on the ulnar aspect of the palm. Initial physical examination revealed no apparent tendon or neurovascular injuries.
Standard evaluation of dog bite injuries includes obtaining a thorough history and physical examination, followed by wound exploration and radiographic imaging to identify possible retained foreign bodies. Radiographic evaluation including multiple views of the left hand and forearm demonstrated a tooth-like radiodensity in the soft tissues at the ulnar dorsal aspect of the distal forearm, with no osseous abnormality. Gas tracking was observed in the soft tissues, predominantly at the volar aspect of the mid to distal forearm/wrist region. Fluoroscopy and ultrasound are commonly used to guide foreign body removal, but in this case, emergency department physicians' fluoroscopy-guided attempt was unsuccessful because of the tooth's depth and surrounding soft tissue structures. Orthopedic surgery consultation resulted in same-day operative intervention.
Surgical exploration included wound irrigation with multiple liters of antibiotic solution containing cefazolin and vancomycin, followed by Betadine solution. Intravenous ampicillin-sulbactam was administered during the procedure. The foreign body was confirmed as a canine tooth by both the surgeon and pathologist. No obvious tendon injury was identified. Animal bite wounds are considered grossly contaminated and require copious irrigation and thorough inspection. Standard protocols include irrigation with tap water or normal saline, inspection for foreign bodies or injuries to bone or tendon, and debridement under local or general anesthesia when necessary.
The patient received a single dose of amoxicillin-clavulanate 875 mg to 125 mg orally during the emergency department visit and was discharged with a prescription for the same antibiotic twice daily for 10 days. He was also administered tetanus immunization, rabies vaccine, and immunoglobulin. No complications were noted at the 3-day follow-up visit, though the patient did not return for the scheduled 2-week wound check.
Specialist or surgical referral is indicated for cases involving systemic infection, significant bleeding, retained foreign bodies, bone or tendon involvement, cranial bites, or wounds requiring reconstructive surgery.
The case report noted that animal bite injuries account for 1% to 2% of emergency room visits in the US. Dog bites specifically represent 80% to 90% of all mammalian bites. Bites to the hand and forearm comprise 18% to 68% of all dog bites and carry increased risk for abscess formation, tenosynovitis, and septic arthritis.
Foreign body retention following dog bites is uncommon and only a small number of cases are documented in the medical literature. Complications associated with retained dental fragments include Pasteurella infections, abscess formation, and chronic granulomatous inflammation.
Standard clinical practice, as reinforced by this case, includes radiographic evaluation to assess for fractures or retained foreign bodies and to provide details about dimensions and positioning of radiopaque foreign bodies. While radiographs can assess soft tissue swelling, MRI is more sensitive for detecting signs of infection in soft tissue. In cases of suspected vascular injury, CT, MRI, and ultrasound imaging can be used to evaluate the vasculature. Ultrasound is commonly employed for assessing radiolucent foreign bodies.
The case was reported by Sam Kaplan and colleagues of Loyola University Medical Center and Loyola University Chicago. The researchers declared no conflicts of interest.
Source: Open Journal of Radiology