Precolombino temporal changes in the prevalence of external auditory exostoses in pre-columbian panama

External auditory exostosis, an abnormal growth of the tympanic bone caused by exposure to cold water and wind, has been reported in pre-Hispanic individuals buried near the Gulf of Panama, where seasonal coastal upwelling creates ideal conditions for their development, even in a tropical climate. In this study, temporal bones from 135 human skeletons excavated from the archaeological site of Cerro Juan Diaz, Panama (AD 50-1500) were analyzed macroscopically to quantify the prevalence of the lesion and identify possible changes in its frequency during specific cultural periods in this village. A high prevalence of external auditory exostoses was found in mostly male individuals from the Early period (before AD 800), whereas no lesions were found in individuals from the Late period (after AD 800). This sharp decline coincides chronologically with the reduction in carved seashell ornaments found in coastal archaeological contexts around the Gulf of Panama, suggesting that diving declined considerably over time, possibly due to a reduced demand for seashells at the local and regional level.