Pediatric Dentistry · patient case question
The panoramic radiograph shows six permanent teeth congenitally absent, excluding third molars. Which term best describes this finding?
Patient case: Seven-Year-Old with Down Syndrome
Patient: 7-year-old male
Chief Complaint: Mother: “He seems to be missing a lot of teeth.”
Background: Trisomy 21. Atrioventricular septal defect repaired at 8 months of age with no residual defect and no prosthetic material. Generalized hypotonia. Cleared by cardiology; no antibiotic prophylaxis required.
Medications: None
Vital Signs: BP 96/60 mmHg · HR 92 bpm · RR 20 · T 98.2°F
Findings: Class III tendency with midface hypoplasia, macroglossia relative to arch size, fissured tongue. Panoramic radiograph shows numerous absent permanent tooth germs and an abrupt angulation of the root of a developing premolar. Cooperative and pleasant at the initial visit.
Show answer and explanation
Correct answer: D. Oligodontia
- A. Incorrect. Anodontia is the complete absence of all teeth in a dentition. It is exceedingly rare and is not what is described here, since numerous teeth are present.
- B. Incorrect. Hypodontia is the correct family of terms but refers to fewer than six missing teeth. With six absent, oligodontia is the precise designation.
- C. Incorrect. Taurodontism — an elongated pulp chamber with apically displaced furcation — is also strongly associated with Down syndrome, and may well be visible on this same film. But it describes tooth morphology, not tooth absence, so it does not answer the question asked.
- D. Correct. Oligodontia is the accepted term for six or more congenitally absent teeth excluding third molars. It is markedly more common in trisomy 21 than in the general population.
Note: Down syndrome dental profile: delayed and irregular eruption, oligodontia, microdontia, taurodontism, fissured tongue, Class III tendency, and early aggressive periodontitis.
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