Study of the Chronologic Development and Eruption of Teeth in Elasmobranchs

¹ Dental Research Department, Naval Medical Research Institute, Bethesda, Maryland

By the use of intravital labeling with tetracycline antibiotics, it has been possible to determine calcification patterns and the rate of exfoliation of elasmobranch teeth. The results indicate that young lemon sharks lose the most peripheral row of teeth in 14-day sequences, with a continuous replacement mechanism restoring the lost teeth from the deeper dental lamina. The technic used is considered to be applicable to the study of calcification mechanisms and calcium and phosphate metabolism in the elasmobranchs as well as to the determination of growth and exfoliation of dental hard tissues.