Posts Tagged ‘teeth’

By Alison George

Human speech contains more than 2000 different sounds, from the ubiquitous “m” and “a” to the rare clicks of some southern African languages. But why are certain sounds more common than others? A ground-breaking, five-year investigation shows that diet-related changes in human bite led to new speech sounds that are now found in half the world’s languages.

More than 30 years ago, the linguist Charles Hockett noted that speech sounds called labiodentals, such as “f” and “v”, were more common in the languages of societies that ate softer foods. Now a team of researchers led by Damián Blasi at the University of Zurich, Switzerland, has pinpointed how and why this trend arose.

They found that the upper and lower incisors of ancient human adults were aligned, making it hard to produce labiodentals, which are formed by touching the lower lip to the upper teeth. Later, our jaws changed to an overbite structure, making it easier to produce such sounds.

The team showed that this change in bite correlated with the development of agriculture in the Neolithic period. Food became easier to chew at this point, which led to changes in human jaws and teeth: for instance, because it takes less pressure to chew softer, farmed foods, the jawbone doesn’t have to do as much work and so doesn’t grow to be so large.

Analyses of a language database also confirmed that there was a global change in the sound of world languages after the Neolithic era, with the use of “f” and “v” increasing dramatically in recent millennia. These sounds are still not found in the languages of many hunter-gatherer people today.

This research overturns the prevailing view that all human speech sounds were present when Homo sapiens evolved around 300,000 years ago. “The set of speech sounds we use has not necessarily remained stable since the emergence of our species, but rather the immense diversity of speech sounds that we find today is the product of a complex interplay of factors involving biological change and cultural evolution,” said team member Steven Moran, a linguist at the University of Zurich, at a briefing about this study.

This new approach to studying language evolution is a game changer, says Sean Roberts at the University of Bristol, UK. “For the first time, we can look at patterns in global data and spot new relationships between the way we speak and the way we live,” he says. “It’s an exciting time to be a linguist.”

Journal reference: Science, DOI: 10.1126/science.aav3218

https://www.newscientist.com/article/2196580-humans-couldnt-pronounce-f-and-v-sounds-before-farming-developed/

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When a 4-month-old boy’s head began to grow abnormally large, doctors were right to assume that something was seriously wrong. After a brain scan revealed a tumor, doctors underwent surgery to remove it. What they found was astonishing — multiple teeth forming inside of his brain due to a very specific type of brain tumor: craniopharyngioma.

The baby boy underwent brain surgery at the University Of Maryland Medical Center, where Drs. Narlin Beaty and Edward Ahn, physicians at University of Maryland Medical Center and Johns Hopkins Children’s Center, respectively, determined the boy had a craniopharyngioma, a benign brain tumor that develops near the pituitary gland. The rare brain tumor can grow to be larger than a golf ball. However, unlike other types of tumors, this one does not spread. “It’s not every day you see teeth in any type of tumor in the brain. In a craniopharyngioma, it’s unheard of,” Beaty told Live Science.

Beaty, however, said that this is not the first time that teeth have been found in a human brain, since they’ve been appeared in teratoma tumors. This was a similar case for a young woman in India. Twenty-three-year-old Nagabhushanam Siva was shocked when she found out that doctors had found two full-formed teeth in the tumor that she had, not in her brain, but in her eye. Also, in 1978, a young man named Doug Pritchard felt a sharp pain in his foot for several weeks before he decided get it checked out. Upon inspection, physicians found a tooth growing in his left foot. However, those tumors, teratomas, contain all the types of tissues found in early-human development — meaning, they have the components of a human child. In contrast, a craniopharyngioma only has one layer.

In the past, whenever scientific abnormalities were discovered, they were often unexplained and many times left untreated. “Before the modern surgical era this child would not have survived,” Beaty said. “He’s doing extremely well, all things considered, this was a big tumor right in the center of his brain.”

https://www.medicaldaily.com/doctors-find-teeth-babys-brain-tumor-plus-other-strange-places-teeth-have-been-found-270380

by Vanessa Zainzinger

Wireless sensors are ubiquitous, providing a steady stream of information on anything from our physical activity to changes occurring in the world’s oceans. Now, scientists have developed a tiny form of the data-gathering tool, designed for an area that has so far escaped its reach: our teeth.

The 2-millimeter-by-2-millimeter devices (pictured) are made up of a film of polymers that detects chemicals in its environment. Sandwiched between two square-shaped gold rings that act as antennas, the sensor can transmit information on what’s going on—or what’s being chewed on—in our mouth to a digital device, such as a smartphone. The type of compound the inner layer detects—salt, for example, or ethanol—determines the spectrum and intensity of the radiofrequency waves that the sensor transmits. Because the sensor uses the ambient radio-frequency signals that are already around us, it doesn’t need a power supply.

The researchers tested their invention on people drinking alcohol, gargling mouthwash, or eating soup. In each case, the sensor was able to detect what the person was consuming by picking up on nutrients.

The devices could help health care and clinical researchers find links between dietary intake and health and, in the long run, allow each of us to keep track of how what we consume is affecting our bodies.

http://www.sciencemag.org/news/2018/03/tiny-sensor-your-tooth-could-help-keep-you-healthy

teeth 1

Surgeons in Mumbai have removed 232 teeth from the mouth of an Indian teenager in what they believe may be a world-record operation.

Ashik Gavai, 17, sought medical help for a swelling on the right side of his lower jaw and the case was referred to the city’s JJ hospital, where they found he was suffering from a condition known as complex odontoma, said head of dentistry Sunanda Dhivare-Palwankar.

“We operated on Monday and it took us almost seven hours. We thought it may be a simple surgery but once we opened it there were multiple pearl-like teeth inside the jaw bone,” she said.

After removing those they found a larger “marble-like” structure that they struggled to shift and eventually had to “chisel out” and remove in fragments.

Ashik’s father, Suresh Gavai, said the family had been worried that the swelling was a malignant growth.

“I was worried that it may turn out to be cancer so I brought him to Mumbai,” Gavai told the Mumbai Mirror newspaper.

Dhivare-Palwankar said the literature they had come across on the condition showed a maximum of 37 teeth being removed in such a procedure, whereas she and her team had counted more than 232 taken from Gavai’s mouth.

“I think it could be a world record,” she said.

Gavai’s jawbone structure was maintained during the operation so it should heal without deformities, the surgeon added.

Thanks to Dr. Nakamura for bringing this to the attention of the It’s Interesting community.

http://www.theguardian.com/world/2014/jul/24/indian-boy-has-232-teeth-removed