Periodontics · patient case question
Which organisms predominate in these deep periodontal pockets?
Patient case: Deep pockets on molars and incisors only
Patient: Female, 22 years old
Chief Complaint: “My front teeth feel like they are moving.”
Background: Healthy. No medications, no allergies, non-smoker. No family history recorded.
Vital Signs: BP 112/70 mmHg · HR 72 bpm · RR 15 · T 98.4°F
Findings: Probing depths 8–9 mm at first molars and 5–6 mm at incisors. Other sites are 2–3 mm. Plaque and calculus deposits are minimal relative to the destruction. Dark, hard subgingival deposits are visible after retraction.
Show answer and explanation
Correct answer: A. Gram-negative anaerobes
- A. CORRECT. As a pocket deepens the oxygen tension falls and the flora shifts decisively toward GRAM-NEGATIVE ANAEROBES — Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola (the red complex), together with Fusobacterium, Prevotella and, in this molar-incisor pattern, Aggregatibacter actinomycetemcomitans.
- B. Obligate aerobes cannot survive the hypoxic pocket environment at all.
- C. Gram-positive rods such as Actinomyces are prominent in early plaque maturation and in root-surface caries, not in the deep anaerobic pocket.
- D. Gram-positive facultative cocci such as Streptococcus sanguinis dominate early supragingival plaque and healthy sulci — the starting point, not the diseased end point.