Oral Surgery · patient case question
Three weeks later a persistent nodule at the lip laceration site requires an incisional biopsy. Which structures are at greatest risk during this procedure?
Patient case: Face-First Fall on Concrete
Patient: 34-year-old male
Chief Complaint: “I tripped and landed on my face on the sidewalk.”
Background: Healthy. No loss of consciousness, no nausea, no visual disturbance. Tetanus status current. Injury occurred approximately 5 hours ago.
Medications: None
Vital Signs: BP 128/78 mmHg · HR 84 bpm · RR 16 · T 98.4°F
Findings: Chin shows a broad, raw, superficially scraped area with punctate bleeding and embedded grit. The inner surface of the lower lip has a full-thickness tear with irregular edges. Teeth #7 and #8 are fractured with frank pulp exposure, tender to percussion, mature apices. Tooth #6 is intact, non-mobile, responds normally to cold, with no radiographic changes.
Show answer and explanation
Correct answer: C. Inferior labial artery and branches of the mental nerve
- A. Incorrect. The superior labial artery and infraorbital nerve supply the upper lip. They are not encountered during a lower lip procedure.
- B. Incorrect. The lingual artery and lingual nerve are floor-of-mouth and tongue structures with no relationship to the labial mucosa.
- C. Correct. The inferior labial artery, a branch of the facial artery, runs between the orbicularis oris and the labial mucosa of the lower lip and is readily palpable. Terminal branches of the mental nerve supply sensation to the lower lip and vermilion; injury produces persistent numbness.
- D. Incorrect. The facial artery courses at the anteroinferior border of the mandible before ascending, well away from the lip. The long buccal nerve supplies the buccal mucosa and gingiva of the mandibular molars.
Note: Practical technique for lower lip biopsy: orient the incision parallel to the vermilion border, remain superficial to the orbicularis oris, and stabilize the lip with digital pressure or a chalazion clamp to control the labial vessels.