Originally published by ADA News - July 14, 2017. Written by David Burger.

Lawrence, Kan. — Since graduating from dental school in 1983, Dr. Joseph R. Gatti has seen thousands of patients and performed thousands of procedures at his practice.

But, he jokes, what he'll probably be known for the rest of his life is being "the Neanderthal dentist."

That's after newspapers around the globe — ranging from his hometown paper to The Washington Post and The Independent (in England) — reported on a unique Neanderthal study led by his friend and dental patient David Frayer, Ph.D., professor emeritus of anthropology at the University of Kansas. Dr. Frayer's study was co-authored by Dr. Gatti, Janet Monge, Ph.D., of the University of Pennsylvania and Davorka Radovčić, Ph.D, curator at the Croatian Natural History Museum in the Croatian capital, Zagreb.

"Dr. Frayer said, 'Look at this — I made you famous,'" Dr. Gatti said.

The significance of the study, first published in The Bulletin of the International Association for Paleodontology in June, is that it suggests that Neanderthals engaged in a form of prehistoric dentistry. The researchers analyzed four mandibular teeth on the left side of a Neanderthal's mouth found at the famous Krapina site in Croatia, with more than 800 fossil remains of Neanderthals.

The Neanderthal examined lived about 130,000 years ago, and the teeth were discovered more than a century ago and originally excavated between 1899-1905. The researchers have reexamined many items collected from the site.

Toothache: Three views of the four teeth from Krapina Dental Person 20. Top: Occlusal viewing showing displaced premolar (arrow), broken lingual margins and partially impacted third molar. The cheek side of the latter is abnormally on the chewing surface. Middle: Lingual view with large chips removed from M1 and M2. Bottom: Cheek side view showing the twisted M3. The black arrow points to toothpick groove and the white arrow points to the worn cheek side of the M3. Photo by Luka Mjeda.

"Neanderthals lived much more complicated, much more sophisticated lives than commonly depicted," said Dr. Frayer. "Besides their DNA linking them to us, there is a lot of paleocultural information like the use of pigments and other adornments, burial patterns, et cetera, making them more like us than anyone ever anticipated. Recent analysis of dental calculus shows DNA sequences indicating that they were using a natural penicillin, and another study shows they were eating mushrooms and another one, chamomile. All these examples suggest a level of sophistication like us."

Dr. Gatti said he has been treating Dr. Frayer for about 15 years, and in that time they have become good friends. While Dr. Gatti has never been to Croatia or had any experience with Neanderthals — not commonly taught in dental schools — he and Dr. Frayer would often discuss paleontology.

So when Dr. Frayer came back to America from a Croatia trip that examined the "Krapina Dental Person 20," he had some questions for Dr. Gatti and requested his expertise. "He said, 'I want to show you some teeth,'" Dr. Gatti said.

Dr. Gatti said the photographs were initially "intimidating," adding that "it's not what I do every day. It's a whole new deal." 

But Dr. Gatti's knowledge was invaluable, Dr. Frayer said, despite the teeth being from the Pleistocene Epoch.

"He helped me with his clinical experience, especially with the possible explanation of the lingual fractures," Dr. Frayer said. "I thought they might have been intentional and he pointed out that he regularly saw patients with lingual fractures, especially on the molars."

There were multiple toothpick-like grooves on the teeth, indications of enamel fractures and signs of other manipulation, leading Dr. Frayer to postulate that the Neanderthal suffered from dental pain from an impacted tooth and was trying to self-treat. The researchers believe the Neanderthal could have been using a bone or stem of grass to treat the dental irritation.

"It is hard to imagine there was not some discomfort, especially with the partially impacted M3," said Dr. Frayer. "There are a few other Neanderthal mandibles with toothpick grooves and periodontal disease, but none with them and a partially impacted tooth."

Dr. Frayer continued: "On the premolar and first molar grooves there is a bony reaction. The scratches on occlusal P4 are limited in scope and very unlikely due to sediment damage. For the lingual cusp fractures on M1 and M2, there is some surface wear near the occlusal, indicating it happened during life."

For Dr. Gatti, the experience was captivating. "That is what I love about dentistry," he said. "On a daily basis, I converse with patients about things I otherwise never would have known. It's fun to be able to add my input."

Dr. Frayer said he plans further study of Krapina Dental Person 20. "We hope to do more work on the broken lingual edges, either through a scanning electron microscope or surface scanning or both. Hopefully, we can get some analysis of the small patches of calculus."

As for Dr. Gatti, "I wouldn't mind taking a trip to Croatia."