Anatomy & Histology · patient case with 2 questions
Ten Days After the Extraction
Patient: 31-year-old female
Chief Complaint: “The pain started three days after the tooth came out and it has been getting worse, not better. It goes up to my ear.”
Background: Tooth #17 was extracted ten days ago. She smokes about half a pack a day and takes a combined oral contraceptive.
Medications: Ethinyl estradiol / levonorgestrel
Vital Signs: BP 118/72 mmHg · HR 78 bpm · RR 16 · T 98.6°F
Findings: The socket is empty of clot with exposed grey bone at its base. Foul odour. No swelling, no purulence, no lymphadenopathy, no trismus.
Question 1
Pain from the exposed bone in this socket is carried by which nerve?
Show answer and explanation
Correct answer: D. Inferior alveolar nerve
- A. The long buccal nerve supplies the buccal soft tissue and gingiva adjacent to the mandibular molars, not the bone of the socket itself.
- B. The facial nerve (VII) is MOTOR to the muscles of facial expression. It carries no general sensation from the jaws at all.
- C. The lingual nerve supplies the lingual gingiva, the floor of the mouth and general sensation to the anterior two-thirds of the tongue — soft tissue, not the alveolus.
- D. CORRECT. The INFERIOR ALVEOLAR NERVE, a branch of V3, supplies the mandibular teeth and the bone of the body of the mandible through its dental and interdental plexus. Exposed alveolar bone and the denuded socket walls of a mandibular third molar site are innervated by its terminal branches — this is why the pain of alveolar osteitis is deep, boring and severe, and why it radiates along the nerve's distribution toward the ear and temporal region.
Note: Referred pain to the ear from a mandibular third molar site travels via the auriculotemporal nerve, which shares the V3 trunk — which is why patients so often describe earache with dry socket.
Question 2
Which feature most strongly separates this from a post-extraction INFECTION?
Show answer and explanation
Correct answer: A. Pain beginning after an initial pain-free interval, with no swelling, fever or pus
- A. CORRECT. The TIMING and the absence of inflammatory signs are decisive. Alveolar osteitis is fibrinolysis of the clot, not an infection: pain characteristically begins on day 2 to 4 AFTER an initial period of improvement, and it occurs WITHOUT swelling, fever, purulence, lymphadenopathy or trismus. A true infection hurts from day one and worsens continuously, with the classic inflammatory signs.
- B. Smoking is the strongest recognised RISK FACTOR, but a risk factor is not a diagnostic criterion.
- C. The mandibular third molar site is the commonest site for dry socket, but it is also a common site for infection — it raises suspicion without settling the diagnosis.
- D. Halitosis occurs in both conditions and does not discriminate between them.
Note: The distinguishing pattern is worth memorising: dry socket = DELAYED-onset pain with a QUIET socket. Infection = pain from the outset with swelling, warmth and pus.