Teeth #7 and #8 are noticeably discolored while all other teeth appear normal. What is the MOST likely cause?

Correct answer: C. Previous trauma to those specific teeth

• A. Tetracycline staining is GENERALIZED and affects all teeth forming during the exposure period, in a banded pattern corresponding to the timing of the drug.
• B. Dentinogenesis imperfecta affects the ENTIRE dentition with opalescent blue-grey teeth, bulbous crowns, cervical constriction, and obliterated pulps.
• C. CORRECT. LOCALIZED discoloration confined to one or two adjacent anterior teeth points to TRAUMA. The mechanism is either intrapulpal hemorrhage with blood breakdown products diffusing into the dentinal tubules (grey-brown discoloration), pulp canal obliteration (yellow discoloration from excessive reparative dentin), or pulp necrosis. Maxillary central and lateral incisors are the most commonly traumatized teeth. Vitality testing and periapical radiographs are the next step.
• D. Fluorosis produces symmetric, generalized white mottling or brown staining in teeth developing during the fluoride exposure period.

Note: Localized = local cause (trauma, caries, endodontic material). Generalized = systemic cause (drug, genetic, developmental).