Final answer:
Tetracycline discoloration is a developmental defect caused by antibiotic use during tooth development, resulting in permanent enamel discoloration.
Step-by-step explanation:
Tetracycline discoloration is a developmental defect that occurs when the antibiotic tetracycline is used during tooth development. The enamel of the teeth can become discolored due to the oxidation of unsaturated fatty acids present in the enamel. This discoloration is permanent and can range from yellow to gray-brown.