Endodontics · patient case question
A different tooth in the same quadrant is tender to both percussion and palpation. Each of the following could explain that finding EXCEPT one. Which is the EXCEPTION?
Patient case: Generalized Caries and a Throbbing Lower Left
Patient: 41-year-old male
Chief Complaint: “The bottom left throbs for twenty minutes every time I drink anything cold.”
Background: No dental care in 6 years. Drinks four sweetened sodas daily. Healthy, no medications, no allergies. Smokes occasionally at social events only.
Medications: None
Vital Signs: BP 122/78 mmHg · HR 74 bpm · RR 16 · T 98.4°F
Findings: Generalized caries. Tooth #19: deep distal caries, exaggerated and lingering response to cold lasting 20 seconds, no percussion tenderness, no periapical radiolucency. Tooth #18: subgingival distal caries with a narrow vertical bony defect on the distal; would require both crown lengthening and root canal treatment to restore. A full mouth radiographic series shows dark bands running across the premolar film.
Show answer and explanation
Correct answer: D. Gingival recession
- A. Incorrect — this explains the finding. Percussion tenderness is the cardinal sign of symptomatic apical periodontitis.
- B. Incorrect — this explains the finding. A symptomatic apical abscess produces marked tenderness to percussion from periodontal ligament inflammation and to palpation from inflammation extending into the overlying tissues.
- C. Incorrect — this explains the finding. Excessive occlusal force inflames the periodontal ligament and readily produces percussion tenderness, sometimes with widening of the ligament space radiographically.
- D. Correct — this is the exception. Gingival recession exposes root dentin and produces dentin hypersensitivity: a sharp, brief response to cold, air, or touch on the exposed surface. It does not inflame the periodontal ligament or periapical tissues, so it produces neither percussion nor palpation tenderness.
Note: Interpret the tests separately. Percussion tests the periodontal ligament; palpation tests the buccal or lingual cortical plate and the overlying soft tissue. Together they localize inflammation beyond the confines of the pulp.