The application of the antibiotic amoxicillin during infancy in Chicago I may lead to enamel defects in permanent teeth. The report was published in the October issue of the Journal of Pediatric and Adolescent Medicine, a JAMA volume. Background information in the article states that fluorosis of dental tissue due to exposure to excessive fluoridation during enamel formation is a common developmental enamel defect. It may manifest clinically as vaguely visible white spots, pitting, or yellow-brown staining. Amoxicillin is a commonly used antibiotic in pediatric patients, primarily for the treatment of otitis media – an infection and inflammation of the middle ear. There has been some previous evidence that amoxicillin may cause enamel defects, and, the authors concluded that even if amoxicillin has minimal effects on enamel, its widespread use has serious implications for public dental health. Dr. Liang Hong of Iowa State University and colleagues evaluated the association between early amoxicillin application in infants and children and dental tissue fluorosis, and Hong is now with the Department of Dental Public Health and Behavioral Sciences at Missouri State University. The researchers analyzed data from the Iowa Fluoride Study, a prospective investigation of fluoride exposure, biological and behavioral factors, and children’s dental health. They followed 579 infant and toddler subjects from O to 32 months, with questionnaires administered every 3-4 months to obtain information on fluoride intake and amoxicillin application. “The results showed that amoxicillin application in early infancy was associated with dental tissue fluorosis in the first permanent molars and maxillary incisors,” the authors reported, “and that there was a correlation between the period of amoxicillin application and the number of fluorosis in the earliest erupting permanent teeth.” Amoxicillin was applied in three-quarters of the subjects surveyed at age one year and in 91% of the subjects at age 32 months. The authors reported: “Overall, 24% of the survey subjects had fluorosis manifestations on the maxillary central incisors.” Amoxicillin application in infants and children at 36 months of age doubles the risk of dental tissue fluorosis. The authors reported: “All levels of statistical analysis showed an association between early amoxicillin application in infants and a significantly higher risk rate of dental tissue fluorosis, and the same conclusion was obtained even after controlling for other potentially relevant factors such as fluoride intake, middle ear infection, and breastfeeding. The authors emphasize that additional laboratory and clinical studies, including controlled studies in experimental animals with different doses of amoxicillin, chemical analysis and histological examination of affected teeth, and a well-designed epidemiological survey, are needed to further confirm this result. They concluded: “The results of this study suggest that the application of amoxicillin in infants and children may lead to a number of hitherto undocumented dental developmental hazards.” Although the results of this study are not sufficient to form a conclusion recommending discontinuation of amoxicillin in infancy, it further emphasizes the need for caution in the use of antibiotics in infancy and early childhood.