New technique permits non-destructive examine of fish tooth

Can we look at the tooth of residing fish and different vertebrates intimately, repeatedly over time, with out harming them? 

Beforehand, small animals typically needed to be euthanized to acquire exact info, however now scientists have discovered a brand new solution to humanely examine detailed dental traits of vertebrates. This customizable technique can be utilized for each residing animals and museum specimens and has been printed within the Journal of Morphology. 

Customizable trays for exact impressions 

Researchers on the Okinawa Institute of Science and Know-how (OIST) and their collaborators utilized human dental impression methods to check fish tooth in a species referred to as Polypterus senegalus. This fish has been separated from different fish species for about 360 million years. Resulting from this lengthy interval of evolutionary isolation, Polypterus nonetheless has many primitive traits that present essential info on the early growth of bony fish. 

The impression course of begins with sedating the animal. Subsequent, the oral cavity is ready by gently air-drying the tooth and utilizing a high-viscosity putty impression materials to scrub them. That is instantly adopted by the appliance of a extra exact, low-viscosity polyvinyl siloxane materials (an impression materials extensively utilized in dentistry) in custom-made, prefabricated 3D-printed trays to seize detailed impressions. All the process usually takes 5 to 10 minutes. 

One of many important challenges confronted by the researchers was working with the small measurement of the fish, as their jaws had been solely concerning the measurement of a finger and particular person tooth had been lower than a millimeter lengthy. Different limitations included the necessity for exact slicing of the impressions for scanning and the shortcoming to see contained in the tooth construction. Nevertheless, the researchers efficiently carried out the process on 60 fish with no fatalities. They noticed detailed microwear patterns – tiny patterns within the tooth floor ensuing from use over time. 

Non-destructive tooth monitoring 

Dr. Ray Sallan, a dentist and researcher at OIST’s Science and Know-how Group, described how the strategy offers a number of important benefits over conventional methods: “Beforehand, researchers needed to euthanize specimens to check their tooth utilizing CT scans or different strategies. This new method permits for non-destructive examination of residing specimens, enabling researchers to trace tooth alternative and growth over time. It’s totally helpful for finding out uncommon species or museum specimens that may’t be broken.” 

The brand new approach has broad purposes in varied fields. It may be used to check microwear patterns to know feeding habits, which is especially helpful in evaluating trendy species with fossils to find out historic dietary patterns. The tactic will also be utilized to check jaw biomechanics, observe developmental adjustments, and look at comparative anatomy throughout species. 

OIST PhD scholar and co-first writer, Johannes Wibisana, from the Genomics and Regulatory Methods Unit highlighted the approach’s versatility in finding out completely different animals. “By checking the identical options throughout completely different species, we will objectively evaluate variations on account of weight loss program, development points, or genetics. This technique permits us to create plots exhibiting variations between species or people. Dental traits from various species present a helpful knowledge set for evaluation,” he stated. 

The researchers are at present engaged on new experiments utilizing this technique with bigger fish specimens and different vertebrates. They’re notably fascinated with finding out tooth alternative patterns, which have by no means been quantified in residing fish earlier than. Solely mammals have everlasting grownup tooth, whereas different vertebrates frequently develop new tooth all through their lives. 

Our technique has many potential purposes and could be extensively used, particularly by museums and researchers sampling biodiversity. We are able to now safely and economically examine and evaluate mouth constructions, revealing variations and meticulous info that wasn’t beforehand accessible.”

Prof. Lauren Sallen, chief of the Macroevolution Unit and senior writer