Pediatric Dentistry · patient case question
What is the most likely diagnosis for the white lesion on the child's canine?
Patient case: Two patients with discoloured teeth
Patient: Adult female, 33 years old — and a separate paediatric patient, male, 9 years old
Chief Complaint: Adult: “My teeth have grey bands across them and I hate smiling.” Child: mother noticed a white patch on an upper canine.
Background: The adult was treated with a tetracycline antibiotic for a prolonged period in early childhood. The child has good hygiene, drinks fluoridated water, and the mark has been present since the tooth erupted.
Findings: Adult: generalised horizontal grey-brown banding of the full dentition, enamel intact and smooth. Child: a well-demarcated opaque white area on the buccal surface of a canine in the MIDDLE third, smooth on probing, no cavitation, away from the gingival margin.
Show answer and explanation
Correct answer: A. Enamel hypocalcification
- A. CORRECT. The location is what decides this. The lesion sits in the MIDDLE THIRD of the buccal surface — a self-cleansing area away from the gingival margin — it has been present since eruption, and the surface is smooth and intact. That is a developmental defect of MINERALISATION: the enamel matrix formed to normal thickness but did not fully mineralise. Hypocalcification.
- B. Hypoplasia is a quantitative defect — the enamel is thin or pitted, so the surface is visibly and palpably deficient. This surface is smooth and intact.
- C. Fluorosis is symmetrical and generalised across teeth that developed at the same time, not a single isolated patch on one tooth.
- D. Incipient caries (a white spot lesion) appears along the GINGIVAL third and around brackets or margins where plaque stagnates, develops after eruption, and typically feels chalky or slightly roughened. The location here argues against it.
Note: Location is the discriminator worth memorising: gingival third and post-eruptive points to demineralisation; middle third, present at eruption, smooth surface points to hypocalcification.
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