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Pathology · patient case with 2 questions

Delayed eruption and a narrow chest

Patient: Female, 12 years old

Chief Complaint: “My adult teeth never came in.”

Background: Father had a similar dental history. No systemic illness.

Findings: Frontal and parietal bossing, hypertelorism. She can approximate her shoulders in front of her chest. Panoramic radiograph: multiple retained primary teeth, numerous unerupted permanent teeth and several supernumerary teeth.

Question 1

Which finding is most characteristic of this condition?

  1. Bilateral multilocular radiolucencies of the jaws
  2. Blue sclerae
  3. Absent sweat glands
  4. Hypoplastic or aplastic clavicles
Show answer and explanation

Correct answer: D. Hypoplastic or aplastic clavicles

  • A. Bilateral multilocular radiolucencies describe cherubism, a different childhood jaw condition with no clavicular involvement.
  • B. Blue sclerae point to osteogenesis imperfecta, often with dentinogenesis imperfecta. Clavicles are not selectively affected.
  • C. Absent or reduced sweat glands belong to hypohidrotic ectodermal dysplasia. In that condition teeth are MISSING; here they are supernumerary — the opposite dental finding.
  • D. CORRECT. Cleidocranial dysplasia (RUNX2 mutation, autosomal dominant) is defined by hypoplastic or completely absent CLAVICLES — which is why the shoulders can be brought together across the chest. The other two limbs of the classic triad are delayed closure of the cranial sutures and fontanelles, and the dental picture of retained primary teeth, multiple unerupted permanents and supernumeraries.

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Question 2

All of the following are features of cleidocranial dysplasia EXCEPT one. Which is the EXCEPTION?

  1. Retained deciduous teeth
  2. Multiple supernumerary teeth
  3. Mandibular retrognathism
  4. Delayed closure of the fontanelles
Show answer and explanation

Correct answer: C. Mandibular retrognathism

  • A. Retained deciduous teeth are the rule, since the permanent successors do not erupt on schedule and the primary teeth have no reason to exfoliate.
  • B. Supernumerary teeth are a cardinal feature, concentrated in the anterior and premolar regions, and they are a major reason the permanent teeth fail to erupt.
  • C. CORRECT as the exception. The mandible in cleidocranial dysplasia is essentially normal in size, while the MAXILLA is hypoplastic — so the face reads as relative mandibular PROGNATHISM, not retrognathism. Midface deficiency with a pseudo-Class III profile is the recognised pattern.
  • D. Delayed closure of the fontanelles and sutures is part of the defining triad; wormian bones are often present as well.

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