Our teeth may come from ancient fish scales

The teeth in your mouth have their origin in the scales of primitive shark-like fish, new evidence suggests.

Sharks and related fish lack bony skeletons and have skin containing tooth-like, spiky scales called dermal denticles.  “Stroke a shark and you’ll find it feels rougher than other fish, as shark skin is covered entirely in dermal denticles,” said Dr Andrew Gillis at the University of Cambridge.

Their tooth-like appearance is no accident, according to new research by Dr Gillis and his collaborators. Over the course of evolution, dermal denticles moved from the skins of primitive fish to the mouth. From there, they could give rise to every vertebrate tooth that has come since, from the 28 centimetre canines of the sabre-toothed cat to the more modest teeth of humans. In this way, our teeth could represent a direct link between us and our distant evolutionary ancestors, the research suggests.

This new study represents the latest contribution to an on-going debate around the origins of teeth. The Cambridge research team examined the embryos of a little skate – a ray-like, cartilaginous fish related to sharks. They used fluorescent markers to label different types of cells in the skate embryos. In doing so, they found that dermal denticles are created from the same type of cells as teeth, known as ‘neural crest cells’.

“Neural crest cells are central to the process of tooth development in mammals,” said Dr Gillis. “Our findings suggest a deep evolutionary relationship between these primitive fish scales and the teeth of vertebrates.”

The fact that teeth and sharks’ denticle scales both arise from the same kind of embryonic cell suggests a common evolutionary origin, the team reported in the journal PNAS. The rough skin of sharks and their other cartilaginous relatives are the evolutionary leftovers of the armour plating that covered fish prior to the evolution of jaws around 400 million years ago. Teeth could be another remnant of this long history.

Dr Gillis and his collaborators suggest that over time, elements of this armour plating have been maintained in different vertebrate lineages while others have been lost.

Source: Independent

Dentures linked to higher risk of weak joints and muscles

A study by scientists at King’s College London has found that over 50s with fewer than 20 of their own teeth are more likely to experience frailty in their joints and muscles.

The reason for this frailty was not proven but the scientists believe it is connected to denture wearers avoiding certain foods and missing out on vital nutrients.

The team found that those with more than 20 teeth were significantly less likely to be frail and consumed the greatest amount of nutrients over the study period.

The participants with fewer than 20 teeth and who did not use dentures – as well as those who did use dentures – were found to have consumed the least amount of nutrients, when compared with the Recommended Dietary Intakes recommended by the US food and drug administration.

Researchers said their findings highlight the important need for older people to be able to maintain the ability to not just chew, but to chew effectively, in order to take on board the essential nutrients necessary to maintain muscle mass and stave off musculoskeletal frailty.

The study, which is published in Geriatrics & Gerontology International, was led by Dr Wael Sabbah of King’s College London Dental Institute. He said: ‘The findings of this analysis, along with that reported in earlier research, suggest that the use of denture could be a neglected intervention that could potentially have a preventative impact on musculoskeletal frailty.’

Traditional Toothbrush May Be Causing Gum Recession

It’s hard to believe that caring for your teeth can damage them, but millions of people each year set themselves up for gum disease. Many people do it improperly, too abrasively, and too often. They wear away the thin enamel of the teeth and erode the gums. This also causes the bone under the gums to disappear and the roots to become exposed. This can result in sensitivity and root decay to take hold.

Without realizing it, people also brush without actually cleaning the area where most disease originates in the teeth. While you might not believe periodontal (gum) disease is waging a slow war on your body, more than 75% of adults over the age of 35 show some degree of signs and symptoms. In fact, gum disease is the leading cause of tooth loss in adults around the world. Continue reading

Toothbrush app makes brushing fun

‘The usual three minutes of brushing will turn into an exhilarating three minutes of discovery’, according to the GUM Play creators from Japan.

They’ve invented a device that attaches to your toothbrush and communicates with an app on your smartphone to help you brush more effectively.

You can choose from 3 apps: Mouth Monster which they say will make any kid, young or old, into big fans of brushing. Mouth Bans which turns your toothbrush into a musical instrument or Mouth News which plays three minutes of audio news while you brush. Continue reading

Squid ink and lasers at the dentist

Engineers at the University of California San Diego have developed a method that uses squid ink to check for gum disease. This strange technique requires a patient to gargle a concoction of food-grade squid ink, water and cornstarch. Lasers are then shined into the mouth causing the dense concentration of melanin nanoparticles to swell which creates differences in pressure within gum pockets. Ultrasound then accurately creates a visual map of your mouth and the depth of the gum pockets reveals the health of your gums. Continue reading

Salami is good for your teeth

Salami isn’t known as a health food but apparently along with butter and soft cheeses it might be good for our oral hygiene.

According to dentist Dr Steven Lin, good dental nutrition is more important than toothpaste. On his website he wrote that teeth were living organs that required proper nutrition to regenerate and maintain healthy levels of enamel and dentin, and that without proper nutrition teeth would struggle to stay intact. Only through getting the right nutrients, vitamins, and minerals could teeth continue to regenerate throughout your life. Continue reading

Alzheimer’s disease drug fixes cavities and regrows teeth

Dental fillings may soon be a thing of the past thanks to a drug being developed and trialed to treat Alzheimer’s disease.

Tideglusib works by stimulating stem cells in the pulp of teeth, the source of new dentine. Dentine is the mineralized substance beneath tooth enamel that gets eaten away by tooth decay.

Teeth can naturally regenerate dentine without assistance, but only under certain circumstances. The pulp must be exposed through infection (such as decay) or trauma to prompt the manufacture of dentine. But even then, the tooth can only regrow a very thin layer naturally—not enough to repair cavities caused by decay, which are generally deep. Tideglusib changes this outcome because it turns off the GSK-3 enzyme, which stops dentine from forming. Continue reading

A vaccine to prevent tooth decay is being developed

Researchers from the Wuhan Institute of Virology (WIOV) of the Chinese Academy of Sciences are working on a vaccine that could help protect teeth against dental decay.

The jab offers a dose of proteins that are effective at removing build-ups of plaque responsible for cavities. Early trials show it to be 64% effective – meaning people would still have to brush their teeth twice a day to avoid a trip to the dentist’s chair.

It offers hope of a ‘fantastic’ answer for preventing or even reversing cavities, which strike a third of adults, according to figures. The researchers said the vaccine would be welcomed in Western countries, where teeth-rotting sugar is consumed heavily.

The research team said the vaccine is still several years away from undergoing clinical tests but experts are excited. Dr Richard Marques, a Harley Street dentist said, ‘This sounds like a fantastic development in dentistry. Preventing tooth decay through vaccination would totally change the dental situation of many children and adults around the world. Dental decay is such a problem and a drain on healthcare resources so this has the potential to transform dental healthcare.’ Continue reading

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