Pathology · patient case with 1 question
Opalescent teeth with bulbous crowns and obliterated pulp chambers
Patient: Female, 11 years old
Chief Complaint: Mother: “Her teeth are grey and they keep chipping.”
Background: Both dentitions affected. Mother's teeth look similar. No history of fractures, no blue sclerae, normal height and no reported bone fragility in the family.
Vital Signs: BP 104/64 mmHg · HR 84 bpm
Findings: Opalescent blue-grey to amber teeth with marked incisal wear. Radiographs show BULBOUS crowns with pronounced cervical constriction, short thin roots and PROGRESSIVE OBLITERATION of the pulp chambers and canals. The enamel appears normal in thickness but is fracturing away from the underlying dentin.
Question 1
What is the diagnosis?
Show answer and explanation
Correct answer: C. Dentinogenesis imperfecta type II
- A. Hypocalcified amelogenesis imperfecta gives enamel of normal thickness that is soft, opaque and rapidly lost, and it is again an ENAMEL condition with normal pulp architecture.
- B. Hypoplastic amelogenesis imperfecta is a defect of enamel MATRIX QUANTITY: the enamel is thin or absent, and on radiographs shows little contrast against dentin. The dentin, pulp chambers and root form are NORMAL.
- C. CORRECT. DENTINOGENESIS IMPERFECTA TYPE II — Shields classification, also called hereditary opalescent dentin — is the ISOLATED dental form, occurring WITHOUT osteogenesis imperfecta. It is autosomal dominant, caused by mutation in DSPP on chromosome 4q, and it affects BOTH dentitions. The absence of bone fragility, fractures, blue sclerae and short stature in this family is what places it in type II rather than type I.
- D. Dentinogenesis imperfecta TYPE I is the dental manifestation OF OSTEOGENESIS IMPERFECTA, arising from COL1A1 or COL1A2 mutation. It carries the systemic picture — bone fragility, blue sclerae, hearing loss, ligamentous laxity — none of which is present here. Type III, the Brandywine isolate, shows multiple pulp exposures and 'shell teeth' with ENLARGED rather than obliterated pulps.
Note: What this item adds is the SUBTYPE tier within DI. Fix it by asking one question — is there BONE disease? Type I means osteogenesis imperfecta is present; type II means the teeth are affected alone; type III means shell teeth with wide-open pulps. Management is the same across all three: full-coverage protection, because the enamel shears off unsupported dentin and the teeth wear to the gingiva if left.