Dentists contribute to Smithsonian exhibit, book on narwhal
May 07, 2018
Tusk test: With a narwhal captured and in stable condition, Dr. Fred Eichmiller (far left) and Dr. Martin Nweeia (far right) begin testing narwhal tusk sensory function using a floating laboratory containing heart and brain monitors to detect physiological response to tusk sensation on Qaqqiat Point, Admiralty Inlet, Arctic Bay. Photo by Gretchen Freund
— With its famous gigantic tooth — a spiral ivory tusk jutting from its upper lip — most people will never set eyes on a narwhal, the near mythical creature known affectionately as the unicorn of the sea.
If you can't make your way to its natural habitat in Arctic waters to witness the phenomenal vision that is the narwhal, then your second best bet is a trip to the Smithsonian National Museum of Natural History. There, led by the efforts of a dentist and curator for the exhibit, Dr. Martin Nweeia, a team of scientists, marine biologists, climate specialists, anthropologists and dentists, have joined efforts for an exhibit that helps demystify the narwhal, including its curious tooth.
The museum opened "Narwhal: Revealing an Arctic Legend," an exhibition, in August 2017 and it will run through 2019. The exhibit encompasses sights, soundscapes, artist renderings, related Inuit culture, a life-size model of a male narwhal with its extraordinary tusk and strands of copious research that has been amassed on the creature.
Leading dental authorities lending voice to the exhibition content include Dr. Nweeia, who lectures on restorative dentistry and biomaterials sciences at Harvard School of Dental Medicine and leads innovative programs at Case Western Reserve University School of Dental Medicine, and Dr. Fred Eichmiller, a past director of the American Dental Association Foundation Volpe Research Center. (The VRC was formerly the Paffenbarger Research Center.)
Studying narwhal tusks: From left, Dr. Fred Eichmiller, National Geographic executive producer Greg Marshall and Dr. Martin Nweeia examine narwhal tusks. The dentists' work is part of an exhibition at the Smithsonian. Photo by Joe Meehan
"It was a very gratifying process to see it come together into a Smithsonian exhibit," Dr. Eichmiller said. "We never dreamed when we started out that it would come to that. When you see that this exhibit is the central banner on the front of the building, it's very gratifying."
Dr. Nweeia, who invited Dr. Eichmiller to join him in exploring narwhals, initiated dental research into the animal's tusk some two decades ago. He discovered that its tooth is quite phenomenal.
"It's a sensory organ with millions of connections to its Arctic environment that is constantly monitoring the surroundings," stated Dr. Nweeia.
"The narwhal has a very different kind of construction from other teeth of mammals, and it is formed almost inside out," he said. "Our teeth are very hard on the outside and gradually as you go inward they get softer. The narwhal is exactly the opposite. It's almost like a loose, flexible sheath, and inside is almost like an iron rod. Within that iron rod is the pulp of the nerves supplying the tooth."
Though the tooth has no use in mastication, it performs other functions. Drs. Nweeia and Eichmiller have made several research sojourns to Northern Canada to observe and study the narwhal — essentially investigating how the whale uses its 6- to 9-foot-long tusk as a sensory organ to explore its environment. Until Dr. Nweeia began studying the narwhal, marine biologists had other theories regarding how the narwhal used its tusk, theorizing that it primarily functioned as a tool that males used to fight for females and dominance.
Elusive narwhal: Expedition team on the ice floe edge outside Pond Inlet in 2002. Photo by Joe Meehan
"There's been a lot of opinions put in the literature as to what the tusk actually was," Dr. Eichmiller said. "Was it a central incisor tooth? Was it a cuspid? If it is a tooth, what's the origin? Some of the early work that we did was to determine exactly what it was. We determined that it was an upper left cuspid and we did a lot of the anatomical work to show how it was innervated and how the blood vessels and nerves communicated with it, so that we could put together a really complete picture."
Whatever its complexity of uses ultimately may be for the narwhal, the tusk, Dr. Nweeia surmises based on the VRC's testing of the tooth, may lend itself someday to dental materials for humans. "They see it as a possibility for restorative materials and other applications of biomimicry," he said. "For example, they're making jet planes out of composites these days. What might they make out of narwhal tusk tissue?"
A book encapsulates some of the research that is foundational to the Smithsonian exhibition. Published in December 2017, the companion book bears the same name as the exhibit.
Open for visitors: The Smithsonian Museum of Natural History is hosting the exhibit, "Narwhal: Revealing an Arctic Legend," through 2019. Photos: James Di Loreto, Kate D. Sherwood and Lucia Martino, Smithsonian
The authors include Smithsonian Arctic Studies Center Director William Fitzhugh as well as Dr. Nweeia. "But there are probably about 40 authors in the book," comments Dr. Eichmiller, "because they pulled in expertise from all areas. It doesn't just talk about narwhals. It talks about whales [generally] and goes a lot into Inuit culture and the hunting culture and things like that."
Dr. Eichmiller contributed a chapter with a co-author, Dr. David Pashley, an expert in dental hard tissues and innervation, around discovery of the sensory abilities within the narwhal tusk.
Exhibit: Led by efforts of Dr. Martin Nweeia, a team of scientists, marine biologists, climate specialists, anthropologists and dentists, have joined efforts for an exhibit at the Smithsonian National Museum of Natural History that helps demystify the narwhal, including its curious tooth. Photos: James Di Loreto, Kate D. Sherwood and Lucia Martino, Smithsonian
Dr. Nweeia noted that Dr. Winston Kuo, a pediatric dentist and Harvard innovator in genetic research, led the chapter on narwhal genetics and sensory genes associated with narwhal tusk function.
The book — "Narwhal: Revealing an Arctic Legend" — is available online through Amazon.com, Barnes & Noble and other retailers.
Dr. Nweeia will discuss his research at ADA 2018 – America's Dental Meeting in Hawaii. His presentation, Narwhal, Arctic Legend and Its Extraordinary Tusk, is set for Oct. 18, 7-9 a.m. (5318). The course with accompanying expedition footage from National Geographic and the BBC, will include a look at narwhal tusk function and how it relates to the function of human teeth and other mammals and why the origins of tooth function are important to consider today. To register, visit ADA.org/meeting
He is also very excited about the prospect of formally or informally encountering other dentists who come in groups to see the Smithsonian exhibition, he said.
For more information on the exhibition, click here
, and for more on narwhals, go to narwhal.org