A 28-year-old smoker taking ethinyl estradiol develops alveolar osteitis five days after extraction of tooth #19. What is the most likely contributing factor?

Correct answer: D. Smoking

• A. Oral contraceptives ARE a recognised risk factor — oestrogen increases fibrinolytic activity — and this is why alveolar osteitis is more common in women. But in a patient with a 10 pack-year smoking history, smoking is the dominant contributor.
• B. Poor oral hygiene and pre-existing pericoronitis do raise the risk, but the case gives no indication of poor hygiene.
• C. Suturing is not required for a routine extraction and its absence is not an established risk factor.
• D. CORRECT. SMOKING is the strongest and most consistently demonstrated risk factor for alveolar osteitis, and a 10 pack-year history is substantial. It acts through several mechanisms: the negative pressure of inhalation physically dislodges the clot, heat disrupts it, nicotine causes vasoconstriction reducing perfusion to the healing socket, and the combustion products directly impair fibrinolysis and healing. Risk rises with the number of cigarettes smoked in the first 24 hours.

Note: Other risk factors: traumatic or difficult extraction, mandibular third molar site, prior alveolar osteitis, and vigorous rinsing or spitting in the first 24 hours. Where extraction is elective in a patient on an OCP, scheduling in days 23–28 of the cycle reduces risk.