"Test of Teeth", written by Tanya M. Smith, translated by Cheng Sun Xuezi, Nautilus 丨 CITIC Publishing episodes, June 2022.
Dental intervention At least 14,000 years ago,
Early dentists first made simple stone tools to clean teeth holes, while older primitive humans could also make toothpicks with plants. A more compelling example is the prehistoric ring sawing technique, which is the intentional removal of part of the skull. The Museum of Modern Anthropology preserves such a skull, showing the amazing surgical skills of Stone Age . This extremely risky surgery is believed to be used to reduce cranial pressure caused by physical trauma. Many patients survived after the operation, and grew new bones to fill the drills produced by the surgery, protecting the brain covered only by the meninges again. But some others are not so lucky. Some skulls have sharp edges and lack repairing bones that grow quickly in the body, indicating that craniotomy is often fatal.
In the Middle Ages, ring sawing was often used as a supernatural or psychotherapy method to protect people from demons or stop abnormal behavior. This technology has even fascinated a few modern people. They have become infamous because of their notorious reputation by drilling holes in their skulls in the hope of achieving legendary spiritual or psychological effects. Similar motivations can also lead to extensive dental modifications, or even complete removal of teeth. Whether good or bad, the popularity of Western aesthetic standards in modern times has greatly weakened these interesting ancient behaviors. Stills from the movie " Crazy Primitive Man " (2013).
Cranial ring sawing is probably the oldest skeleton surgery, but dental intervention followed closely, occurring at least 14,000 years ago. The discovery of adult male bones in a rock cave in Italy provides compelling evidence. This is not a regular prehistoric burial, because his body is accompanied by a set of bone and stone tools, covered with stones coated with ochre-red pigment. The use of this natural pigment and weapon to bury the man shows that the man is extraordinary, and evidence from his teeth cements his position in history. After careful examination of the skeleton, the researchers noticed that there was a small pit on the chewing surface of his third molar, with its enamel peeling off and deep scratches inside. There are multiple cavity inside and around the pit, resulting in a large amount of enamel loss, causing the dentin to be painfully exposed. These scratches are very similar to common cuts on slaughtered bones, indicating that the pit was once dug deep by sharp tools.
To determine which tool caused these traces, the research team began to use small wood, bone and stone tools from this period to "treat" modern human teeth. Among them, the stripes produced by the stone tool are very similar to those on the teeth of the Italian male, indicating that this is likely a tool used to deal with the diseased area. Importantly, scratches and peeling enamel on the periphery of the pit were polished after surgery, while deeper scratches retained the sharp edges. It seems that the patient survived after treatment and continued to chew on his teeth for a while. The research team proposed the hypothesis that this surgical treatment represented human adaptation to toothpick use, which was already very common at the time.
animation "Toothbrush Family" (1997) poster.
The development and spread of agricultural and industrial sugar production have made tooth caries an epidemic for modern people. As agriculture and dental caries became more and more common, ancient dentists also developed increasingly complex surgical methods. For example, teeth unearthed in a cemetery of Pakistan , 7500-9000 years ago showed obvious signs of dental treatment. The chewing surface of multiple molars has conical holes, about a few millimeters in width and depth, just like a small hole chiseled with a pen or a small screwdriver at the tip. Using a microscope to carefully observe the inside of the hole, we see a spiral ring created by the rotating tool, just like it was produced when drilling.
researchers also used experiments to understand the process of the generation of these holes and test the efficacy of flint drills found at archaeological sites.Sharp stone bow drills are often used to make beads, and the predecessor of this modern tooth drill proved to be very efficient! Within a minute of manual rotation, the flint drill can create a circular hole in modern teeth, exactly the same as those in prehistoric individuals. These interventions allow patients in Pakistan to continue using their teeth after surgery, as the edges of the drilled holes are smoother than the inside, similar to those of male molars in Italy. These surgeon pioneers cleverly adapted the use of common tools and techniques to relieve people's oral discomfort. As you will see below, they also create extraordinary fashion statements and exquisite abstract decorations.
Will prehistoric dentists also remove sick teeth?
Modern dentists do not simply drill holes in their teeth and let the patient go. They have developed many ways to protect fragile crowns and highly sensitive roots. In the Stone Age without refined metals, ceramics and plastic resins, dentists then had to use natural materials as ointments. A male jaw unearthed from in Slovenia was from 6500 years ago, showing evidence of soothing therapy. His canine teeth have obvious wear and cracks, which appear to be covered with beeswax, which may be used to fill the cracks while reducing discomfort. In this case, beeswax does not record slight wear like enamel, so it is difficult for researchers to determine whether beeswax is used before an individual dies, let alone how long before death. There is also a waxy substance buried beside an Italian skeleton from 14,000 years ago. The pits on his molars also contain organic residues, but scientists cannot yet judge what substance it is made of.
It is well known that identifying organic matter in prehistoric environments is extremely difficult because in most cases, the invasion of microorganisms will lead to their degradation and loss. In ancient times, it was very likely that humans used natural products to relieve pain, but we also needed to discover more courageous dental patients to know clearly whether their pain was truly relieved.
When caries or dental infection reaches a critical value, modern doctors will remove the diseased teeth and leave holes in the gums and bones, but as long as the infection is completely cleared, these holes will eventually heal and repair slowly. Tooth extraction is a path to no return because our teeth do not replace spontaneously, and the remaining teeth are usually different from before.
In addition to scraping and drilling holes in the patient's crown, will our prehistoric dentists also remove sick teeth? Unfortunately, this question is almost impossible to answer until there is a recorded history. In the late stages of dental disease, the tissue-attached system will weaken, and loose teeth will fall off with only a small amount of pressure. Shaking with your fingers may also speed up the natural fallout of teeth. Many children and even chimpanzees have mastered this method when shaking their breast teeth. The most critical issue is that it is difficult for us to tell whether a diseased tooth falls off naturally or is intentionally removed. The teeth I studied in modern dental clinics usually retain certain marks of removal, such as subtle scars left by metal tweezers, or traces left by sharp probes when released. However, due to the lack of similar evidence of ancient interventions, scientists were unable to determine the origin of tooth extraction. Stills from the movie "The Adventure of the Dentist" (1965).
Dotolescence is a close relative of the preventive tooth removal, that is, active removal of healthy teeth, which suddenly appeared thousands of years ago. The traditional customs of modern small societies are very helpful in identifying and interpreting the behavior of prehistoric human , especially for those of us who decipher skeletal evidence, because some activities are completely unfamiliar. Cultural anthropologists have discovered that humans around the world have loose teeth of and to break out. In many cultures, some or all of the incisors are removed, and children's breast teeth may also be pulled out before they fall off naturally. Teeth removal can occur at different ages and can occur multiple times in a person's lifetime. I admit, it’s hard for me to understand the behavior of tooth loss. Generally speaking, individuals who receive releasing will not receive any anesthesia.In some cases, the patient must always remain calm during the process and endure the iron nails, thin knives, or tools made of wooden sticks and stones to completely remove the crown and roots of the tooth. For those of us who just imagine the process of cleaning teeth, we have really encountered strong opponents. We spend a lot of money on protecting healthy teeth, and it’s irresponsible to give up them!
Why do people remove teeth that are not sick? Some scholars believe it is a body modification, like tattoos, piercings or shavings. Many people embellish themselves in different ways to express our cultural identity or group affiliation as well as identity and gender characteristics. The causes of tooth dislocation vary from culture to culture, and may be due to aesthetic values, symbolic intimidation, or a ritual of adulthood or mourning. It seems to give some social benefit, or has a strong personal meaning, making people willing to accept the risk of pain and infection, as well as the loss of the function of the teeth. Other possible reasons include language formation, tool use, basket making, and even enabling poor people with autism to eat. The earliest conclusive evidence of tooth dislocation comes from the skeletal remains of African hunter-gatherers, about 13,000 to 15,000 years ago, including a large number of adult individuals with a high proportion of anterior teeth. This tradition may have originated in the Maghreb region in northwestern Africa and has been spread throughout Africa for thousands of years, and some tribes still have the custom of losing their teeth. However, skeletal evidence from ancient Japan, Southeast Asia and Australia points to the interesting idea that tooth dislocation originated independently in multiple continents at different times.
We have seen that it is difficult to distinguish between intentional dental removal and disease-induced shedding. More complexity is that incisors and canine teeth have simple bevel roots, making them easy to fall off the jaw bone after death. Therefore, novices can easily mistakenly consider after death shedding or congenital loss as intentional removal. Dental anthropologists therefore set specific criteria to judge tooth dislocation in skeletal remains. Generally speaking, if a dead individual lacks the bone around the incisors, it appears that there is no disease in the presence of symmetric teeth on the left and right sides, and if the alveolar bone around the missing teeth begins to regenerate, the individual is considered to have experienced tooth dislocation. If multiple individuals in the population have such a pattern, it will be even more exaggerated.
These criteria can help us evaluate a possible case of tooth dislocation in prehistoric humans in the Lakes of Willandra, Australia. An individual who lived about 40,000 years ago seemed to have lost two lower canine teeth at the same time and lived for a long time afterwards. This individual is called the "Mongge" and is the earliest human remains discovered in Australia. The body of this indigenous individual is covered with red ochre brought from a distance, indicating that his social identity is very prominent. The second individual in of the Wilandra Lake District lacked two lower central incisors, and the person also continued to live long enough to make the bones completely filled. Steve Webber first described them academically, leaving behind the possibility that missing teeth were intentionally removed. Although the two individuals have multiple indicators of tooth dislocation, more remains with similar missing teeth are needed in the area to further confirm and consolidate the ancient nature of this extraordinary behavior. The use of
toothpick is the oldest known dental operation. The use of
toothpick may have appeared nearly 2 million years ago, making it the oldest known dental operation. Scientists have found clear cross grooves on the teeth of two African primitive human species, more than 1,000 miles apart. They belong to the capable and Homo erectus, and were very early members of the human race. Can you believe that the slender grooves on the sides of these teeth fossils were formed by the use of a toothpick? This view was proposed by a European dentist in 1911 and has been controversial since then. Decades later, the famous paleontologist Franz Wei Dunrui also opposed the idea of the use of toothpicks by ancient primitive humans, believing that it was "too absurd to be true."
Thankfully, biological anthropologist Leslie Rusco recently helped solve this problem.She designed a clever experiment using natural grass stem toothpicks as well as baboon and human skulls. Grass contains very small hard particles that can cause subtle scratches and slowly wear out the enamel during the chewing activities of a person throughout his life. Before starting the experiment, Leslie installed artificial gums on the bones around her teeth, soaked the bones for a whole day, and kept them moist during subsequent toothpick use. She started with the baboon skull and slashed her teeth briefly with a toothpick for 8 hours, leaving slender horizontal lines on the surface. When it was proven that simple grass stems could leave groove marks on baboon teeth, Leslie turned to the human jaw bone to start working. The experiment also formed slender horizontal grooves, almost exactly the same as the fossils of a human being 2 million years ago. She explained to me that she used a toothpick to process jaw at an academic seminar, and that boring activity was just right for some research! Similar groove marks also appear on the teeth of Ethiopian , the Republic of Georgia and China, as well as the teeth of the Heidelberg and Neanderthal , which shows that toothpicks have been widely present long before modern people appear. In fact, toothpick use is probably the earliest hygiene habit we can see in the fossil record. Stills from the movie " Tooth Fairy " (2010).
However, Great Ape is not surpassed by human cousins, and they also use twigs to fiddle with their teeth. Will McGru, Caroline Tittan and Jane Goodall have documented the shocking dental behavior of a group of captive chimpanzees at Tulane University in the United States. This group was transferred from the birthplace of Africa to Louisiana and lived comfortably together for a few years until things started to get interesting.
First, it was observed that a young female named Bell began to fiddle with her loose breast teeth, and other pups in the group began to do so. When she started fiddling with her teeth with a small wooden stick, several individuals followed suit. One day, Bell was seen cleaning teeth for a young male named "Banditt" using cigarette-sized pine branches. Shockingly, Bandit also volunteered to accept Bell's care, while other individuals gathered to watch Bell's movements as he watched Bendit's oral. Eventually, Bell successfully took one of Bandit's breast teeth and took it into his pocket a few minutes later. The breeders eventually successfully diverted their attention to retrieve the chimpanzees’ dental tools and teeth. This is a rare souvenir for the life of the Tooth Fairy ! Stills from the movie "Tooth Fairy" (2010).
People have known for a long time that chimpanzees can use tools, carefully select and prepare fine wooden sticks for catching termites, and even take care of "stick dolls". So, it is no surprise that they will use wooden sticks to fiddle with their teeth. Perhaps even more surprising is that chimpanzees will voluntarily receive intimate care provided by another individual, which is an extremely anxious experience for many human dental patients! However, chimpanzees and other primates have extensive social care behaviors. They spend hours combing the other hair with their hands, teeth and lips. In chimpanzee groups, dental care (whether or not) usually occurs during longer periods of body care. This conventional social connection is likely to help Bandit relax and receive Bell’s dental services.
Cleaning teeth is not common in non-human primates
If you have ever stuck the shell of popcorn kernels in the gaps between teeth or under your gums, you must be very clear about how sudden and uncomfortable the discomfort in your mouth can be. This feeling is shared by us and apes and monkeys. To relieve discomfort, we pick teeth with a toothpick or floss, and our primate relatives have similar behaviors. For example, a captive female macaque will use the hair on her body or the combed subject as floss to perform routine dental cleaning.But partners don’t always tolerate her picky about oral hygiene, sometimes raising objections when she pulls her hair too hard! Similarly, macaques living freely in Thailand will also ride on tourists' heads, pull off human hair, and then use it to clean their teeth. Mothers will even teach this technique to their offspring. When babies are close, they will have more pauses, repetitions, and last longer.
Macaques are not the only monkeys that use floss to clean teeth. Someone once photographed a female baboon in captivity pulling a hair from a broom in the room to clean the upper and lower teeth of the mouth. Wild orangutans, chimpanzees and bonobos will also use branches or sticks to clean teeth. Our young chimpanzee patient, Bandiet, once used a ribbon-like cloth to clean up the loose breast teeth and finally successfully removed them. Captive chimpanzees with mirrors in the room sometimes use mirrors to check the inside of the mouth and clean their teeth. Although these behaviors may not leave an indelible mark like the toothpick experiment, they still prove that inhuman primates have an inherent perception of their oral environment and have the ability to change it. Stills from
short film "Tate" (2015).
These anecdotes I share may leave you with the impression that cleaning teeth is very common in non-human primates, but these behaviors are actually not common. Although one or even a group of innovative individuals may clean their teeth regularly, other individuals actually rarely imitate such behavior. This limits the chances of the behavior being exchanged between groups or being passed on intergenerational.
Researchers have proposed various theories to explain the widespread existence of toothpick use in human genus. Some people think it is gingivitis, or periodontal disease it causes drives primitive humans to use toothpicks. Ancient teeth with toothpick groove marks are usually looser in connection with bones, but we must also remember that the fossilization process makes it difficult for us to judge the health of an individual before death. Peter Angal and his colleagues support the idea that toothpick use may be due to daily meat consumption. It is difficult for us to assess whether eating hard or fiber-rich wild foods prompted our ancestors to use toothpicks. If this is true, then we don’t know why toothpick use was not common until 1.8 million years ago. Evidence of animal slaughtering was nearly 1 million years earlier than the earliest human members. Furthermore, we are not the only primates that eat carnivorously. Some chimpanzees hunt monkeys every day, and orangutans occasionally catch and eat slow-moving primates, lazy monkeys.
Evidence from non-human primates and ancient primitive humans complicates the direct link between toothpick use, oral health, and dietary structure. I can’t help but wonder whether modern people who love to eat meat pick their teeth more frequently than those who prefer vegetarians or vegetarians? I am looking forward to the opportunity to ask the dentist such a question when I go for a half-year dental cleaning!
It is well known that exploring recorded human behavior is very difficult. Because hard tissues of teeth are easier to retain than tissues in other parts of the body, they become the main source of information for population and cultural differences before studying text records. Dental operations such as tooth dislocation, filing and mosaic are direct evidence of individuals’ past behavior. Other forms of body modification, including tattoos and scars, cannot be preserved for a long time after death. Decorations like clothing are also prone to rot. Cracking cultural information about teeth modification is a big challenge. Burial and fossilization processes can blur, distort, and even damage key evidence. Research on small modern societies shows that time and place are key factors in interpreting this form of symbolism in many aspects of human behavior. We are doing our best to build an anthropological framework that combines knowledge from dental biology, archaeology, non-human primate behavior and intercultural perspectives.
Note: The content of this article is excerpted from the book "Test of Teeth" with authorization from the publisher. It has been deleted and modified from the original text. The title is added by the editor.
Original author/[US] Tania M. Smith
excerpted/An Ye
edited/Luo Dong
