Anatomy & Histology · patient case question
What is the typical root and pulp horn anatomy of tooth #4?
Patient case: Deep caries on an upper premolar
Patient: Female, 36 years old
Chief Complaint: “Cold drinks hurt on my upper right, but it stops as soon as I swallow.”
Background: Healthy, no medications.
Findings: Tooth #4 has deep occlusal caries approaching the pulp with no radiographic periapical change; it responds sharply but briefly to cold and is not tender to percussion. Tooth #7 in the same patient is non-vital with a well-circumscribed periapical radiolucency; the excised soft tissue was submitted for histopathology.
Show answer and explanation
Correct answer: C. One root with two pulp horns
- A. Two roots is the maxillary FIRST premolar (#5 on this side), which is bifurcated buccopalatally in most cases — the classic distinction between the two maxillary premolars.
- B. Three pulp horns implies a three-cusped tooth — a mandibular second premolar of the three-cusp type, or a molar.
- C. CORRECT. Tooth #4 is the maxillary right SECOND premolar. It has a single root the large majority of the time (roughly 85 to 90 percent), usually with a single canal, and its two-cusped crown gives it TWO PULP HORNS, buccal and palatal. The buccal horn is the taller of the two.
- D. A single pulp horn belongs to a single-cusped tooth such as a canine.
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