A 16-year-old patient with obliterated pulp chambers across multiple teeth, generalized yellow-brown discoloration, and no responsiveness to pulp testing — no history of trauma. Most likely diagnosis:

Correct answer: B. Dentinogenesis imperfecta type II (isolated, not associated with OI)

• A. Tetracycline staining causes extrinsic-appearing horizontal banding (yellow-gray-brown), NOT pulp obliteration across all teeth.
• B. Correct. Generalized yellow-brown discoloration with OBLITERATED PULP CHAMBERS across all teeth (no history of OI/blue sclera) = Dentinogenesis imperfecta type II (DI-II, isolated hereditary opalescent dentin). DI-II affects BOTH dentitions equally, shows opalescent/yellow-brown color, bulbous crowns, cervical constriction, and pulpal obliteration. Not associated with OI (DI-I is).
• C. Regional odontodysplasia affects a specific region/quadrant with ghost teeth (poorly mineralized) — not generalized across all teeth.
• D. Amelogenesis imperfecta affects ENAMEL (hypoplasia, hypocalcification, or hypomaturation patterns) — pulp chambers are normal. Color varies but pulp obliteration is not a feature.