47 Fun Facts About Teeth

Scurvy makes gums swell and bleed until teeth can fall out; a lack of which vitamin leads to it?

Vitamin C: it comes mainly from fruit and vegetables, and most people treated for scurvy start feeling better within days.

A baby's first teeth usually arrive at around six months; which ones most often come through first?

Bottom front teeth: the top pair usually follows, but some babies start teething before four months, and a few are even born with a tooth.

Which Arctic animal hauls itself onto ice with its tusks and sucks shellfish out of their shells?

The walrus: apart from its tusks its teeth are flat, so it seals its lips to its prey and pulls back a piston-like tongue to create a vacuum.

Why can the damaged outer layer of a tooth never grow back?

It contains no living cells: saliva and fluoride can put back minerals lost in early decay, but once a cavity forms, the body can't rebuild the lost enamel.

The proverb 'don't look a gift horse in the mouth' comes from checking a horse's teeth to judge what?

Its age: a horse's gums recede as it grows older, making its teeth look longer, which also gave us the phrase 'long in the tooth'.

Which whale has no teeth at all and strains krill through plates of baleen instead?

The blue whale: the largest animal ever to live gulps huge mouthfuls of krill-filled water, then pushes the water out through its baleen with its tongue.

The pointed 'eye teeth' take their other name from the Latin word for which animal?

Dogs: canine comes from Latin canis, 'dog', and the upper ones are called eye teeth because they sit just beneath the eyes.

What is the technical name for a gap between two teeth?

A diastema: many mammals have one as a normal feature, and in horses that toothless gap is exactly where a rider's bit rests.

Which acid, made by mouth bacteria feeding on sugar, is the main cause of tooth decay?

Lactic acid: each sugary snack sets off a fresh acid attack, which is why sipping and grazing all day does more damage than one dessert.

What is the soft tissue at a tooth's core, carrying its nerve and blood vessels, called?

The pulp: if decay or a crack lets bacteria infect it, a root canal clears it out, or the tooth may have to be pulled.

Which wild pig's upper tusks grow up through the top of its snout and curve back toward its forehead?

Babirusa: if a male's tusks aren't worn down, they can keep growing and, in rare cases, pierce its own skull.

In medieval Europe, narwhal tusks were sold as what?

Unicorn horns: buyers believed the horns could protect them against poison.

About how many teeth does a great white shark have at any one time?

About 300: they sit in rows that move forward like a conveyor belt, and a great white keeps growing replacements as long as it lives.

The largest known shark teeth, more than seven inches tall, belonged to which extinct species?

Megalodon: a shark's skeleton is cartilage that rarely fossilises, so megalodon is known almost entirely from teeth like these.

A snail's rows of microscopic teeth sit on which ribbon-like feeding organ?

A radula: some predatory sea snails pair it with an acid secretion to drill through other molluscs' shells and eat what's inside.

Which group of molluscs has no rasping tongue-ribbon at all?

Bivalves such as clams: they have no head either, and their big gills do the feeding, trapping food in mucus that cilia carry to the mouth.

Which burrowing East African rodent digs its tunnels with its big front teeth?

The naked mole-rat: it lives in colonies like an ant's nest, where only the queen breeds while workers dig the burrows with those teeth.

Which animal goes through up to six sets of cheek teeth in its lifetime?

The elephant: new teeth don't grow up from below but form at the back of the jaw and push the worn ones forward and out.

Which animal nicks skin with razor-sharp front teeth, then laps up the blood that flows?

The vampire bat: anticoagulants in its saliva keep the blood from clotting, so the wound keeps flowing while it feeds.

A rodent's gnawing teeth stay razor sharp because the hard coating covers only which side of them?

Enamel covers only the front face of a rodent's incisors; the softer tissue behind wears away faster, leaving a self-sharpening chisel edge.

About how many times may a crocodile replace each of its roughly 80 teeth over its life?

About 50 times: a small replacement tooth waits under each working one, and each tooth is swapped out roughly once a year.

What do hippos mainly use their huge lower tusks for?

Fighting: hippos battle with those tusks, while the chewing is left to their molars.

What does a giraffe have instead of upper front teeth?

A hard palate, or dental pad, meets the lower incisors, as in cattle; the giraffe strips leaves with a 45 cm dark tongue whose colour may protect against sunburn.

Which French physician's book The Surgeon Dentist earned him the title 'father of modern dentistry'?

Pierre Fauchard: he rejected the old idea that worms caused tooth decay, blaming acids from sugar instead, and filled cavities with tin or lead.

What is the medical term for habitually grinding or clenching the teeth, often during sleep?

Bruxism: stress and anxiety are common triggers, and it can wear teeth down and leave the jaw painful.

In which country was the oldest known dental work, a 14,000-year-old cleaned tooth, found?

Italy: a 14,000-year-old molar from Riparo Villabruna in the Dolomites had decay scraped out with a flint tool; Stone Age dentists at Mehrgarh in modern Pakistan were drilling teeth with bow drills around 7000 BC.

Which official under Pharaoh Djoser is often called the earliest named dentist?

Hesy-Ra: one of his titles can be read as 'great one of the dentists', though it may instead mean 'great one of the ivory cutters'.

The world's first dental college opened in 1840 in which American city?

Baltimore: yet John Harris had already been training dental students at a small school in Bainbridge, Ohio.

What were George Washington's dentures made from?

Ivory and human teeth: none of his sets used wood, and he complained that his dentures made his lips bulge out.

The Etruscans made partial dentures from the 7th century BC by fastening teeth with bands of what?

Gold: some writers have called these appliances ancient braces, but reviews find no evidence they were used to move teeth.

Which American city was the first in the world to add fluoride to its water supply, in January 1945?

Grand Rapids, Michigan: the idea traced back to dentist Frederick McKay, who found that children with 'Colorado brown stain' had fewer cavities.

Why did US guidelines once call for less added fluoride in tap water for warmer places?

They drink more water: the dose matters, because too little does little for decay while too much leaves white streaks on children's teeth.

The first bristle brushes for teeth, hog bristles on bamboo or bone handles, came from which country?

China: when such brushes reached Europe, users found the hog bristles too stiff and preferred softer horsehair.

The first nylon-bristle toothbrush, sold in 1938, used fibre from which chemical company?

DuPont: its new nylon went into toothbrush bristles in 1938, a year or more before the famous nylon stockings reached the shops.

What is the name for inflammation of the gums, the earliest stage of gum disease?

Gingivitis is gum inflammation caused by plaque along the gumline, showing as red, swollen gums that bleed when brushed; untreated it can progress to periodontitis, which destroys the bone around teeth.

Which company first sold toothpaste in jars in 1873, and later adopted the collapsible tube?

Colgate: the company had started out making soap and candles, and it moved its toothpaste from glass jars into tubes in 1896.

The first fluoride toothpaste to win American Dental Association approval was which brand?

Crest: royalties from Procter & Gamble helped Joseph Muhler's Indiana University team set up a dental research institute there.

In 1819, dentist Levi Spear Parmly recommended flossing with waxed thread made of what?

Silk: Parmly called the waxed silken thread the most important part of cleaning, since it dislodged matter no brush could reach.

In 1844 dentist Horace Wells had his own tooth pulled to demonstrate which anaesthetic?

Nitrous oxide: after seeing Gardner Colton's laughing-gas show, Wells had John Riggs pull his molar under the gas in December 1844; his Boston demonstration weeks later went wrong and he was mocked as a humbug.

In Spain and much of Latin America, which character collects children's lost teeth instead of a fairy?

Ratoncito Pérez: the mouse came from folk tales, but Luis Coloma made him a collector of lost teeth in an 1894 story for eight-year-old King Alfonso XIII.

Which early Christian martyr is popularly regarded as the patron saint of dentists?

Saint Apollonia: church tradition says her torturers broke or pulled out all her teeth, so she is invoked against toothache and shown holding a tooth in pincers.

Who identified Joseph Warren's remains months after Bunker Hill by a false tooth he had fitted?

Paul Revere: the remains showed that Warren had been shot in the head, most likely dying instantly.

Which serial killer's murder conviction relied partly on now-discredited bite-mark evidence?

Ted Bundy's 1979 Chi Omega conviction rested partly on a bite mark on a victim matched to his teeth; the National Academy of Sciences has since concluded bite marks cannot reliably identify a person.

Which organisation developed the nickel-titanium alloy later used to make wire for dental braces?

The Naval Ordnance Laboratory: braces use the alloy because it springs back toward its original shape, giving teeth a steady push.

Which term describes animals whose milk teeth are replaced by a set of adult teeth?

Diphyodont: the milk teeth still matter, since they help keep the right spacing for the adult teeth that follow.

What is the thin bone-like layer covering a tooth's root, where the periodontal ligament attaches, called?

Cementum: it is normally hidden below the gumline, so seeing it usually means the gums have receded, often a sign of gum disease.

Premolars are also known by what other name?

Bicuspids: they have at least two cusps, and unlike molars they appear only in the adult set, taking the place of the baby molars.