Under what age does tetracycline staining typically occur in patients?

Tetracycline staining, which results in a discoloration of the teeth, is primarily associated with the use of tetracycline antibiotics during certain stages of tooth development. The critical period for tetracycline to cause permanent staining occurs when the developing teeth are exposed to the drug. This exposure is particularly concerning in children, typically under the age of 8 years, when the permanent teeth are still forming.

The age range identified in the correct answer reflects this understanding, as the years from birth to 5 encompass the crucial developmental stages for both primary and the early-formed permanent teeth. During this time, if tetracycline is administered, it can be incorporated into the mineralization process and cause staining.

In contrast, the other age ranges either extend beyond the critical window of development (as with 6-12 years) or are more limited, failing to encompass the critical developmental stages adequately. As a result, the most appropriate age range when tetracycline staining typically occurs is up to 5 years.