180 Fun Facts About Dental & Dentist

How many permanent (adult) teeth does a person usually have?

32 adult teeth include four wisdom teeth, which often stay trapped in the gums or jaw because there is no room left for them by the time they come through.

How many baby (primary) teeth does a child normally grow?

20 baby teeth include no premolars at all: the baby molars are the ones that fall out to make way for the adult premolars.

Which thin tooth coverings did a California dentist invent in 1928 to perfect film actors' smiles?

Veneers began as film props: Charles Pincus's 1928 originals were stuck on only for the cameras, and it took acid-etched bonding decades later to make them a lasting fix.

What is the soft tissue in the center of a tooth, full of blood vessels and nerves, called?

Pulp is what a root canal removes: the dentist cleans out the infected tissue and seals the space, so the tooth itself can stay in the jaw.

Which of the four tissues of a tooth sits between the outer enamel and the inner nerve chamber?

Dentin is laced with microscopic tubes, so when its protective covering wears away, heat, cold and acidic foods reach the nerve inside: the cause of sensitive teeth.

Which type of tooth is designed mainly for tearing food?

Canines grip food so it can be torn apart, and in many mammals they double as weapons, which is why males often grow far larger ones than females.

Premolars are also known by what other name?

Bicuspids, named for their two points, are the healthy teeth most often pulled to make room when crowded teeth are straightened.

Wisdom teeth are formally known as which teeth?

Third molars got their nickname because they arrive so late, probably as a translation of the Latin dens sapientiae.

Which bacterium is most closely associated with tooth decay?

Streptococcus mutans feeds on sugar and excretes acid, and it is that acid, not the sugar itself, that eats into the surface of a tooth.

'Caries', the dentist's word for cavities, comes from a Latin word meaning what?

Decay is what the Latin caries meant, used of crumbling wood, walls and bones; the tooth kind is now the world's most common health condition, though it is largely preventable.

An ancient Mesopotamian tablet blamed cavities on what?

A tooth worm, thought to eat teeth away from within, was still being blamed for toothache in the 18th century, when a dentist with a microscope reported finding none.

Which ancient law code ordered a man's teeth knocked out for knocking out the teeth of an equal?

The Code of Hammurabi tied the penalty to rank: knock out the teeth of an equal and you lost your own, but a lower-ranked victim's teeth cost only a fine.

Hesy-Ra, an official of the pharaoh Djoser, is often credited with what dental distinction?

He is the earliest named dentist on the strength of a single title, which Egyptologists read either as 'great one of the dentists' or as 'great one of the ivory cutters'.

Which Frenchman is credited as the 'father of modern dentistry' for his 1728 book The Surgeon Dentist?

Pierre Fauchard borrowed his tools from watchmakers, jewellers and barbers, and warned his patients that sugar was what rotted their teeth.

Before modern forceps, tooth-pullers worked with a clawed tool named after which bird?

The dental pelican, named for a claw shaped like the bird's beak, pulled teeth for about four centuries; its successor, the dental key, was no kinder, often breaking the tooth or the jaw.

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

The Baltimore College of Dental Surgery opened in 1840; Cincinnati's Ohio College of Dental Surgery followed in 1845 and later graduated the first woman dentist.

Who was the first woman in the world to graduate from a dental college, in 1866?

Lucy Hobbs Taylor graduated from the Ohio College of Dental Surgery in 1866 after being refused for her sex; she had simply opened her own practice in 1861 instead.

Hartford dentist Horace Wells pioneered surgical anesthesia in 1844 using which gas?

Nitrous oxide never made Wells rich: he chose not to patent it, and two years later his former student William Morton won the fame by demonstrating ether instead.

How did Horace Wells first test his anesthetic gas on 11 December 1844?

On his own wisdom tooth: the day after watching a volunteer at a gas show hurt his leg without noticing, Wells breathed the gas himself while his colleague John Riggs pulled the tooth.

Which material was actually in George Washington's dentures, which were never made of wood?

Hippopotamus ivory, along with human and animal teeth and lead, made up his dentures; ivory stains quickly, which may be how the wooden-teeth myth started.

How many natural teeth did George Washington have left on the day of his first inauguration in 1789?

One tooth, a premolar, was all he had left; when it too came out, Washington gave it to his dentist John Greenwood as a keepsake.

Which Revolutionary hero and part-time dentist identified a friend's body by a false tooth he had wired in?

Paul Revere had wired the false tooth into Dr Joseph Warren's mouth himself; when Warren was dug from a shared grave months after Bunker Hill, his face was unrecognisable but the wire was not.

Which ancient people made partial dentures held with gold bands as early as the 7th century BC?

The Etruscans shaped replacements from human or animal teeth and fixed them in gold bands, a craft the Romans are thought to have borrowed from them.

In which US city was water fluoridation first tested, starting on 25 January 1945?

Grand Rapids, Michigan saw tooth decay among children born after the switch fall by more than 60 percent within 11 years, and fluoridation became national health policy.

Dentist Frederick McKay spent 30 years chasing the cause of which condition, later traced to fluoride in drinking water?

Colorado brown stain looked alarming, but McKay found the mottled teeth were surprisingly resistant to decay, the clue that later led to fluoride being added to tap water.

Until 2015, US guidance recommended less fluoride in the drinking water of which communities?

Hotter towns were told to add less because children there drank more water; the sliding scale was scrapped in 2015 after studies found that, in the age of air conditioning, they no longer did.

The first nylon-bristle toothbrush went on sale in 1938 thanks to which company's new fiber?

DuPont's nylon made its commercial debut in a toothbrush, before nylon stockings reached the shops; it took over from the boar bristles that toothbrushes had used until then.

The Broxodent electric toothbrush was invented in 1954 by Dr Philippe-Guy Woog in which country?

Switzerland's Broxodent plugged straight into a wall socket and was first meant for people who struggled to brush by hand, such as patients with limited motor skills or braces.

What was the toothbrush's earliest known ancestor, used in ancient Mesopotamia and Egypt some 5,000 years ago?

The chew stick was made by chewing one end of a twig until it frayed into a brush, while the other end served as a toothpick; the miswak twigs still used today are the same idea.

In the US, daily tooth brushing became a widespread habit only after which event?

World War II soldiers were ordered to brush every day and kept the habit when they came home; toothbrushes had been on sale in the US for decades, but daily brushing had never caught on.

Dr. Washington Sheffield put toothpaste in a collapsible tube after his son saw what in Paris?

Painters squeezing paint from tubes showed his son Lucius a cleaner way to sell a paste that had come in open jars; the first toothpaste tubes were made of lead.

Ancient Roman tooth powders got their grit from burnt horn, oyster-shell ash and which powdered stone?

Pumice went into Roman tooth powder beside the ash of deer horn, ox bone and oyster shell, some of it mixed with myrrh; Pliny the Elder wrote that such powders also firmed loose teeth and eased toothache.

Which toothpaste brand is known for its red, white and blue stripes?

Aquafresh began in 1973 with only two stripes, blue and white, and added the red later; the trick of striping paste as it leaves the tube is older still, from a US patent filed in 1955.

During World War II, physician Charles Bass used nylon to reinvent which everyday tooth-cleaning item?

Dental floss in nylon resisted shredding and came in long, even lengths; Bass was a medical school dean, renowned for his research on malaria and hookworm.

Dentist Alfred Fones trained his cousin Irene Newman in 1906 to be the world's first what?

Dental hygienist was a name Fones coined himself; he wanted Newman's successors working in schools, cleaning children's teeth to prevent disease rather than repair it.

Which dental specialty deals with root canals and diseases of the tooth's inner tissue?

Endodontics exists to save teeth that would otherwise be pulled: a root canal clears out the infected core and seals what is left, so the tooth keeps working.

Edward Angle, creator of the edgewise appliance, is the father of modern what?

Orthodontics became dentistry's first recognised specialty largely through Angle, who opened a school devoted to it in St. Louis and sorted bad bites into a system still used today.

Which US dental charting scheme counts the adult teeth in one run from the upper right wisdom tooth?

The Universal Numbering System is universal in name only: it is the American habit, while most of the world charts teeth with the two-digit FDI codes.

One of the tooth fairy's earliest mentions in print, a 1908 household hint, ran in a newspaper in which city?

Chicago's Daily Tribune printed reader Lillian Brown's tip that a stubborn child would give up a loose tooth if told the tooth fairy would swap it for a small gift under the pillow.

In Spain and much of Latin America, which animal takes the tooth fairy's place, collecting children's lost teeth?

A mouse, Ratoncito Pérez, became the tooth collector in an 1894 tale written for Spain's eight-year-old King Alfonso XIII, who had just lost a tooth.

Which early Christian martyr, her teeth broken before she was burned, is invoked against toothache?

Saint Apollonia was seized by an Alexandrian mob that broke out her teeth and threatened to burn her unless she renounced her faith; given a moment's freedom, she leapt into the fire herself.

Roughly how many teeth can some shark species shed and regrow in a lifetime?

Some sharks go through about 35,000 teeth, replacing whole rows continually; Pliny the Elder thought fossil shark teeth fell from the sky in eclipses until Nicolaus Steno set the record straight in 1667.

The narwhal's spiral tusk is actually what?

A canine tooth, usually the left one, breaks through the male's lip at two or three years old and never stops growing; scientists still argue over whether it is a weapon, a display or a sense organ.

Which order of mammals has a single pair of continuously growing incisors in each jaw, forcing them to gnaw constantly?

Rodents, named from the Latin for 'to gnaw', have no choice: their incisors never stop growing and, left unworn, can grow long enough to pierce the skull.

Which human teeth typically have three roots each?

Upper molars usually have three roots, and they reach so close to the sinus above that their tips can poke through its floor; lower molars make do with two.

What material is used for tooth-coloured fillings that bond to the tooth?

Composite resin bonds to the tooth instead of being wedged into a shaped hole like amalgam, so the dentist can often drill away less healthy tooth; it sets hard under a curing light.

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

It contains no living cells: the ameloblasts that build enamel die off around the time the tooth erupts, so a cavity is permanent until a dentist fills it.

Which adult teeth arrive at about age six without replacing any baby teeth?

First molars come up behind the last baby teeth, in some children before any other adult tooth, so nothing falls out to announce them; the adult teeth further forward all fill spaces that baby teeth leave.

Which human teeth have the longest roots?

The upper canines are anchored by the longest roots in the mouth, sunk so deep that they raise a visible ridge on the surface of the jawbone.

What is the part of a tooth visible above the gum line called?

The crown is the enamel-covered part you can see, and it gives its name to the dentist's crown, an artificial cap made to replace that same visible portion of a damaged tooth.

What is the technical name for a gap between two teeth, like the one Madonna has?

Diastema is known in France as dents du bonheur, 'lucky teeth', and in children it is often temporary: the gap tends to close by itself as the adult teeth come in.

Mouth bacteria turn sugar mainly into which acid, which dissolves tooth enamel?

Lactic acid attacks enamel each time the bacteria are fed, so teeth that meet sugar again and again through the day lose more mineral than they can win back.

What is the anatomical name of the upper jaw bone that holds the upper teeth?

The maxilla is really two bones joined along the midline of the palate; when the two halves of the palate fail to join up before birth, the result is a cleft palate.

In medieval Europe, narwhal tusks were sold as what?

Unicorn horns were prized as a defence against poison, so narwhal tusks changed hands for many times their weight in gold; Denmark's coronation chair is built from them.

Which shark carries about 300 serrated, triangular teeth and preys on seals and sea lions?

The great white tears off mouthfuls by shaking its head from side to side, and its rows of teeth move forward like a conveyor belt to replace any that are lost.

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

Megalodon is known almost entirely from its teeth: no complete skeleton has ever been found, so scientists estimate the size of the whole shark from the size of a tooth.

A snail carries thousands of microscopic teeth on a ribbon-like organ called what?

A radula works like a rasp, and a limpet's has to scrape food off bare rock: its teeth, laced with fibres of an iron mineral, tested stronger than spider silk.

Which group of molluscs is the only one without a rasping tongue-ribbon?

Bivalves such as clams have no head at all, let alone a toothed tongue: they draw in water and sieve tiny food from it instead.

An elephant's tusks are enormously overgrown versions of which kind of tooth?

Incisors, not canines, form an elephant's tusks, and each animal favours one of them: the 'master' tusk it uses most ends up shorter and blunter.

Which pet sheds 28 baby teeth and grows 42 adult ones?

Dog owners may find the odd puppy tooth on the floor from about three months on, but most are swallowed harmlessly with dinner.

A rat's gnawing teeth stay chisel-sharp because the hard coating covers only which side of them?

The front face alone is armoured with enamel; the softer tissue behind wears away faster, so every bite grinds the tooth back to a chisel edge.

Which animal's teeth, made of thin hexagonal tubes, give its order the name Tubulidentata?

The aardvark is the only living member of Tubulidentata; its teeth have no enamel coating, so they wear away constantly and keep regrowing for life.

Which reptile can replace each of its roughly 80 teeth up to 50 times in a lifetime?

The crocodile keeps a small replacement tooth, and a stem cell to grow the next one, waiting beside every full-grown tooth, ready to move in when the old one is lost.

What do giraffes, like cattle, have in place of upper front teeth?

A dental pad is a tough cushion of gum that the lower front teeth press against, shared with cattle, sheep and other cud-chewers; a giraffe adds a 45 cm tongue to pull the leaves in.

Dentures set with dead soldiers' teeth are now known by the name of which battle?

Waterloo left tens of thousands of dead soldiers in one place, and scavengers pulled their teeth to sell to denture makers, who prized them because they came from healthy young men.

The oldest known treated cavity in a modern human was found at Riparo Villabruna in which country?

Italy's Riparo Villabruna rock shelter held a 14,000-year-old skeleton whose decayed molar had been scraped with pointed flint tools, treatment that predates farming and the cavities it made common.

James Morrison's 1871 dental drill was driven by what?

Foot treadle power drove Morrison's drill; where hand-turned drills had crawled, his cheap engine spun a bur fast enough to cut a tooth smoothly, and it transformed everyday dentistry.

What does the dental degree abbreviation DDS stand for?

Doctor of Dental Surgery is the older title; Harvard's dental school, founded in 1867, gave its degree a Latin name instead, which is why some dentists are DMDs with exactly the same training.

In the 1964 TV special Rudolph the Red-Nosed Reindeer, which elf wants to be a dentist?

Hermey the elf abandons toy-making to become a dentist and ends up pulling the Abominable Snow Monster's teeth; the Rankin/Bass special has been broadcast every year since 1964.

Which American dentist, called the father of operative dentistry, devised the standard classification of cavities?

G. V. Black sorted cavities into numbered classes by tooth and surface; his motto 'extension for prevention' meant widening a filling into nearby grooves so they could not decay later.

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

China produced the first bristle brushes, hog bristles set in bamboo or bone; when travellers carried the idea west, Europeans found hog bristle too firm and preferred softer horsehair.

Which fairground treat was invented in 1897 by Nashville dentist William Morrison and a confectioner?

Cotton candy came from the electric spinning machine Morrison built with candy-maker John Wharton; sold as 'Fairy Floss' at the 1904 St. Louis World's Fair, the dentist's sugar cloud shifted 68,655 boxes.

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

Colgate began in 1806 as a New York starch, soap and candle maker; it only added aromatic toothpaste, sold in jars, in 1873, and switched to collapsible tubes in 1896.

Which brand, developed by Procter & Gamble in the 1950s, was the first fluoride toothpaste to win American Dental Association approval?

Crest's stannous fluoride formula came from Joseph Muhler's team at Indiana University; Procter & Gamble's patent royalties then paid for a dental research institute there, nicknamed 'the house that Crest built'.

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

Parmly's waxed silk thread is the first recorded floss, yet nobody sold the stuff commercially until 1882; Johnson & Johnson's 1898 patent used the same silk that surgeons stitched with.

In Finding Nemo, the dentist who scoops up Nemo keeps his office in which city?

Sydney is where dentist Philip Sherman keeps Nemo, in a tank in his harbourside office at '42 Wallaby Way'; the other fish plot his escape before Sherman can hand him to his fish-killing niece Darla.

What is the dental specialty devoted to treating children called?

Pedodontics, now usually called pediatric dentistry, treats children from infancy through adolescence; US guidance is a first dental visit by the first birthday, so that early decay is caught while it is simple to treat.

Which execution device was first proposed in 1881 by Buffalo dentist Alfred Southwick?

The electric chair occurred to Southwick after he heard of a drunk man killed instantly by a generator; used to working on seated patients, he pictured the condemned in a chair too, as a kinder end than hanging.

Delta Dental says its Tooth Fairy Poll payout usually tracks what?

The S&P 500 and the tooth fairy have usually risen and fallen together, the insurer says; its poll put a tooth at $1.30 in 1998, though its 2023 and 2025 polls each found the two moving in opposite directions.

Which teeth usually erupt first in a baby?

The lower central incisors usually come through first, with the upper pair a month or two behind; very occasionally a baby is born with them already showing, which doctors call natal teeth.

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

Ted Bundy's 1979 conviction for the Chi Omega murders leaned on a bite mark on victim Lisa Levy, matched to casts of his teeth; a 2009 National Academy of Sciences report later led courts to restrict such testimony.

The Nitinol wire used in modern braces was created in 1959 by which organisation?

The Naval Ordnance Laboratory's William Buehler was looking for an alloy for missile nose cones; the name NiTiNOL adds the lab's initials to nickel and titanium, and its springy wire later found its way into braces.

Orthodontics is the dental specialty that deals with what?

Orthodontics corrects misaligned teeth and jaws with constant gentle pressure: the tooth loosens and shifts, then new bone grows in to hold it in its new position, which is why treatment takes months.

Which Nazi leader's 1945 remains did Soviet investigators identify through his dental bridgework?

Adolf Hitler's charred remains were matched by Soviet investigators to his dental records and bridgework, confirmed by his dentist's assistant Käthe Heusermann in May 1945.

In Angle's system, which class describes an underbite?

Class III, with the lower molars ahead of the upper, is the underbite; its best-known case is the 'Habsburg jaw', which a 2019 study of the dynasty's portraits tied to generations of inbreeding.

Braces invented by Craven Kurz in 1976 are fixed to which surface of the teeth?

Kurz's lingual braces sit on the inner, tongue side of the teeth, which makes them nearly invisible; the trade-off is a tongue that takes a while to adjust to them.

Dental sealants are painted onto which part of the teeth to block decay?

Sealants are thin resin coatings painted into the pits and fissures of molar chewing surfaces, usually in childhood, blocking the grooves where food and bacteria lodge.

Where did Zia Chishti get the idea for Invisalign?

Chishti, wearing a retainer as an adult patient to finish his own orthodontic treatment, reasoned that a series of such devices, each slightly different, could move teeth a long way in small steps.

The best-known removable retainer, with a metal wire around the six front teeth, is named after whom?

The Hawley retainer, named for its inventor Charles Hawley, holds the front teeth with a wire set in an acrylic plate; because that wire can be bent, an orthodontist can still use it for small finishing movements.

Orthodontic headgear differs from braces in what obvious way?

Headgear differs because it is worn partly outside the mouth: straps round the head or neck anchor a facebow that holds back the upper jaw's growth, often for 12 hours or more a day.

Boston dentist George Franklin Grant, Harvard's first African American faculty member, patented which piece of sports equipment in 1899?

The golf tee Grant patented was a wooden peg, and pegs like it spared players a chore: until then every drive began by building a small mound of sand to perch the ball on.

What is an extra tooth beyond the normal count called?

A supernumerary tooth is any extra beyond the normal set; the commonest kind, a mesiodens, sits between the two upper front teeth and can stop them from coming through.

Bleeding, spongy gums in scurvy come from a lack of which vitamin?

Vitamin C is needed to make collagen, so without it gums swell and bleed and teeth loosen; James Lind's 1747 citrus trial pointed the way to a cure.

What is the process, in which titanium bonds to bone, that underpins modern dental implants?

Osseointegration, Per-Ingvar Brånemark's term for living bone bonding directly to titanium, was found by accident when a titanium chamber set in a rabbit's leg bone could not be removed.

Per-Ingvar Brånemark, who fitted the first modern titanium dental implants in 1965, worked in which country?

Sweden's Brånemark, working in Gothenburg, gave Gösta Larsson, who was born with a cleft palate, titanium implants in 1965; they were still in place when Larsson died some 40 years later.

Chemist Alfred Einhorn's 1905 local anesthetic gave dentists a safer substitute for which drug?

Cocaine was the main local anesthetic until then, but its toxicity and addictiveness sent chemists hunting for a replacement; Einhorn's Novocain was comparatively safe.

Lidocaine, the dentist's staple anesthetic, was first synthesized in 1943 under what name?

Xylocaine was the name Nils Löfgren's Stockholm team gave it in 1943; his young colleague Bengt Lundqvist tested the new anesthetic by injecting it into himself.

Which pioneer of antiseptic surgery is the namesake of a mouthwash brand first formulated in 1879?

Joseph Lister only lent his name: St. Louis chemist Joseph Lawrence borrowed it in 1879 for a surgical antiseptic, which was not promoted to dentists for oral care until 1895.

Listerine's sales took off in the 1920s when it was marketed as a cure for what?

Chronic halitosis was a little-known medical term for bad breath until Listerine's 1920s adverts turned it into a dreaded social failing; the same liquid had earlier been sold as a floor cleaner.

Dentist Otto Walkhoff took one of the first dental X-rays in January 1896, weeks after which physicist discovered the rays?

Wilhelm Röntgen found X-rays in November 1895; within weeks Walkhoff held a glass photographic plate in his own mouth for an exposure said to have lasted about 25 minutes.

Which disease, diagnosed soon after he qualified as a dentist, sent Doc Holliday west in search of a drier climate?

Tuberculosis had already killed Holliday's mother; he took his dental degree in Philadelphia at 20 and opened a practice back home, then left for the Southwest hoping the air would help, and turned to gambling.

Which author of Riders of the Purple Sage ran a New York dental practice before his Westerns sold?

Zane Grey studied dentistry at Penn on a baseball scholarship and opened as 'Dr. Zane Grey' in New York in 1896, writing in the evenings to escape the tedium of the work.

So-called silver fillings are actually about half which metal by weight?

Mercury, liquid at room temperature, is mixed with powdered silver, tin and copper into a putty that can be packed into the cavity before it sets hard; a Chinese text of 1505 already gave a recipe.

What inert material is typically used to fill cleaned canals at the end of a root canal treatment?

Gutta-percha, a rubbery latex from Southeast Asian trees, softens when heated and does not react with body tissue; the same inert toughness made it the insulation for 19th-century undersea telegraph cables.

Which actor plays Stu, the dentist who loses a tooth in The Hangover?

Ed Helms needed no effects for the gap: one of his adult front teeth never grew, and the implant he had worn since his teens was simply taken out for the shoot.

What is the primary mineral in tooth enamel?

Hydroxyapatite, a crystalline calcium phosphate, makes up nearly all of enamel's mineral; fluoride converts its surface to more acid-resistant fluorapatite.

What is the medical term for excessive teeth grinding or jaw clenching?

Bruxism often goes unnoticed by the person doing it, especially during sleep; in time it can leave the jaw aching, flatten or crack teeth and wear enamel through to the layers beneath.

Xerostomia is the medical term for which condition?

Xerostomia is dry mouth from too little saliva, a common side effect of many medicines; without saliva to buffer acid and wash away food, decay accelerates.

What is the dentist's word for tartar, a term it shares with a branch of mathematics?

Calculus is plaque hardened by minerals from saliva; the word is Latin for a pebble, and it also gave maths its term because Romans did their reckoning with small stones.

Baleen plates, which filter-feeding whales have instead of teeth, are made of what?

Keratin, the protein of hair and fingernails, forms the fringed plates that strain food from seawater; people long sold it as 'whalebone' for corset stays and parasol ribs, though it is not bone at all.

Which Ice Age sabre-toothed cat left thousands of bones in the La Brea Tar Pits?

Smilodon's sabres were slender and could break under sideways strain, so the cat first wrestled prey down with its powerful forelimbs and only then delivered a precise killing bite.

Which actor plays the torturing dentist Christian Szell in Marathon Man?

Laurence Olivier's Szell drills into Dustin Hoffman's Babe without anesthetic while asking 'Is it safe?'; the role earned Olivier a 1977 Oscar nomination.

Who plays the sadistic dentist Orin Scrivello in the 1986 film Little Shop of Horrors?

Steve Martin's Orin Scrivello gets his own song, 'Dentist!', then meets his match in Bill Murray's Arthur Denton, a patient who enjoys the pain and asks for 'a long, slow root canal'.

Xylitol, the tooth-friendly sweetener, is nicknamed after which tree it can be extracted from?

Birch gave xylitol the nickname 'birch sugar' because it can be extracted from the wood, yet when Emil Fischer first isolated it in 1890 he was working with chips of beech.

William Addis is said to have devised the first mass-produced toothbrush in the 1770s while he was where?

In prison after a riot, the story goes, Addis decided that rubbing teeth with a sooty rag was useless; he drilled holes in a leftover bone, tied in bristles, and built the firm now called Wisdom.

At roughly what age does teething, the eruption of the first baby teeth, typically begin?

Six months is the typical start, though anything from four to seven is normal; despite the folklore, teething does not cause a real fever, so a high temperature points to something else.

Which Arctic mammal uses its long tusks to haul itself out of the water onto ice?

The walrus hauls out on its tusks so routinely that naturalists named its genus Odobenus, from the Greek for 'tooth-walker'.

Which actor plays Willy Wonka's candy-banning dentist father in Charlie and the Chocolate Factory (2005)?

Christopher Lee's Dr. Wilbur Wonka forbids his son all sweets; he is not in Roald Dahl's book, and Tim Burton added him to explain how Willy turned out so strange.

Who plays the predatory dentist Dr. Julia Harris in the 2011 comedy Horrible Bosses?

Jennifer Aniston's Dr. Julia Harris torments her dental assistant, played by Charlie Day; writer Michael Markowitz based her on a boss of his own and wanted Aniston for the part from the start.

Hominin teeth with 'toothpick' grooves from 1.8 million years ago were found at Dmanisi in which Caucasus country?

The Dmanisi jaw from Georgia shows grooves worn by a toothpick 1.8 million years ago; a Neanderthal from Cova Foradà in Spain used one to ease gum disease.

In the 17th century, toothpicks were treated as what?

Seventeenth-century toothpicks were jewel-set luxury objects of gold or silver kept in cases; Romans had favoured mastic-wood picks, and delicate silver examples survive from antiquity.

Evidence of dentistry using bow drills around 7000 BCE comes from which ancient civilisation?

At Mehrgarh in the Indus Valley, skilled bead craftsmen may have operated the bow drills, cutting holes 3.5 mm deep with concentric grooves in eleven molars.

Sri Lanka's Temple of the Tooth guards a tooth said to be whose?

The Buddha's tooth was long believed to give whoever held it the right to rule the island, so Sinhalese kings kept it beside their palaces, and Kandy's temple stands in the old royal complex.

The contra-angle air-turbine handpiece was invented by John Patrick Walsh's team in which country?

John Patrick Walsh's team at the Dominion Physical Laboratory in Wellington, New Zealand built it in 1949; the angled shaft lets the spinning burr reach the mouth's less accessible corners.

Which chemical is the active ingredient in most tooth-whitening products?

Hydrogen peroxide oxidises the stain molecules in enamel; it is often delivered as carbamide peroxide, a stable complex that releases it on contact with water.

In which sport did the mouthguard originate?

Boxing produced the first mouthguards: fighters used to clench cotton, sponge or bits of wood between their teeth until British dentist Woolf Krause began making mouthpieces for them in the 1890s.

Which 1947 innovation by Los Angeles dentist Rodney Lilyquist let athletes talk normally while protected?

A transparent acrylic splint, moulded to fit over the upper or lower teeth, was Lilyquist's design; dentists then campaigned for such guards, and US high-school football made them compulsory from the 1962 season.

Cheap denture bases from the 1850s were moulded from which material?

Hardened rubber, sold as Vulcanite after Charles Goodyear's process, could be moulded cheaply to the mouth and set with false teeth, putting dentures within ordinary people's reach for the first time.

Which two bacteria are most closely tied to the gum disease periodontitis?

Porphyromonas gingivalis and Treponema denticola belong to the 'red complex' of bacteria found in severe gum disease, which is considered the main cause of tooth loss in adults worldwide.

Dentist Thomas Welch pasteurised which drink in 1869, launching a brand that still carries his name?

Grape juice was Welch's answer to a church problem: a teetotal Methodist, he wanted Communion wine without alcohol, so he heat-treated the juice to stop it fermenting and sold it as 'Dr. Welch's Unfermented Wine'.

Baby teeth are formally called deciduous teeth, a word more often used for which living things?

Trees that shed leaves each autumn share the label because deciduous means falling off once a part is no longer needed. Antlers that deer drop every year earn the same word.

For children aged three to six, the NHS advises using an amount of toothpaste the size of what?

A pea is the NHS measure for ages three to six, while children under three get only a smear. From seven most children can brush alone, though parents are told to keep watching.

US pediatric dentists want a child's first visit soon after the first tooth, or by which milestone?

Turning one is the deadline shared by the American Academy of Pediatrics and its dental counterpart. Parents leave with a home-care plan plus advice on diet and preventing mouth injuries.

Which anatomical name belongs to the lower jawbone, the skull's largest and only movable bone?

The mandible begins as two halves that fuse at the chin during the first year of life. It hinges on the temporal bones, just in front of each ear.

Which word names the fear of dental care that keeps sufferers away until pain forces a visit?

Odontophobia, also called dentophobia, is eased with methods ranging from music therapy and guided imagery to conscious sedation. With children, dentists often use a routine known as tell-show-do.

Which university introduced the DMD dental degree because it granted its degrees only in Latin?

Harvard found that the Latin for the existing dental title would not shorten to DDS. After consulting a Latin scholar it adapted the wording of its medical degree instead, and the DMD was born.

The sharp hooked instrument a dentist runs over teeth to feel for flaws is called a dental what?

Explorer is the formal name, though many patients know it as the sickle probe. Its fine tip carries vibrations to the handle, so the dentist can feel irregularities too small to see.

Josiah Flagg built the first dental chair by adding a headrest to which style of wooden seat?

Windsor was the style, a plain wooden seat that Flagg upgraded with an adjustable headrest plus an arm extension to hold his instruments.

Which calcified tissue covers the root of a tooth and anchors the fibres that hold it in the jaw?

Cementum is light yellow and keeps forming throughout life. Fresh layers are laid down so the tooth's attachment stays intact as the older surface ages.

Which term describes upper and lower teeth that fail to meet properly when the jaws close?

Malocclusion, in Edward Angle's definition, is any deviation of the bite from the ideal. A childhood diet of soft, cooked food is among the suspected causes, because the jaws then grow smaller.

Which part of fixed braces threads through every bracket and supplies the force that moves teeth?

The archwire is tied into each bracket with small ligatures, which come in colours the patient can choose. Orthodontists bend and tighten it at check-ups to steer the teeth.

What do orthodontists call the small bands hooked from upper to lower braces to fix a bite?

Elastics come in many strengths and were pioneered by Calvin Case and Henry Baker. The Class II kind runs from a lower back tooth to an upper eye tooth.

Which childhood habit can tip front teeth outward and cause an open bite once adult teeth arrive?

Thumb sucking does no harm in toddlers, and most children give it up by themselves between two and four. Any damage is reversible if the habit ends before the permanent teeth arrive.

The word orthodontist pairs the Greek for 'tooth' with a Greek word that carries which meaning?

Straight is the core sense of the Greek orthos, which can also mean true or correct. English borrowed the older form orthodontia in 1849.

America Ferrera's title character is known for her adult braces in which ABC comedy-drama?

Ugly Betty kept its heroine in braces until an episode titled Million Dollar Smile. The series was based on the Colombian telenovela Yo soy Betty, la fea.

Clear ceramic braces use a material developed with which agency for heat-seeking missile trackers?

NASA worked with the company Ceradyne on translucent polycrystalline alumina, made to protect the infrared antennae of missile trackers. Its see-through toughness suited so-called invisible braces.

Alginate, the paste orthodontists use to take moulds of teeth, is refined from which natural source?

Seaweed supplies alginate, which also thickens drinks and ice cream. A single species used, giant kelp, can grow 20 to 40 metres long.

Mewing, a jawline craze named after orthodontist John Mew, centres on the resting position of what?

The tongue, in Mew's theory, widens the upper jaw simply by resting in the right place. Reviewers have found inadequate evidence that the do-it-yourself method works.

Nickel-titanium braces wires go limp when cold but spring back at body heat, a property called what?

Shape memory lets an orthodontist thread a chilled, floppy wire through crooked brackets with ease. Once warmed by the mouth it stiffens and seeks its original curve, pressing lightly and constantly.

Braces work because steady pressure prompts which cells to clear bone from a moving tooth's path?

Osteoclasts take their name from the Greek for 'bone' and 'broken', and they digest bone by secreting acid and an enzyme. A related cell eats away the roots of baby teeth before they fall out.

Invisalign founders Zia Chishti and Kelsey Wirth met at the business school of which university?

Stanford classmates Chishti and Wirth founded Align Technology in 1997 and began developing a clear aligner. Chishti was ousted from the company in 2002.

Which bite problem is a sideways mismatch, with a tooth set further in or out than its partner?

Crossbite is a lateral misalignment of the two arches. In a child who still has baby teeth, it may come from the teeth themselves or from the way the jaw bones have grown.

Traditional 'train track' braces use which alloy, a problem for patients allergic to its nickel?

Stainless steel contains nickel, so allergic patients are often fitted with gold-plated or titanium braces instead. The titanium kind is lighter and just as strong, but costs more.

Which Roman medical writer first recorded straightening a tooth by regular pressure from a finger?

Celsus compiled the encyclopedic De Medicina, the only surviving section of a much larger work. Earlier still, Hippocrates and Aristotle had pondered ways to straighten teeth.

Which technical term describes jaw surgery for bite problems too severe for braces alone?

Orthognathic surgery is also a highly successful treatment for obstructive sleep apnoea. It often includes braces before and after the operation.

C. Loring Brace argued that Europeans developed an overbite only after adopting which eating tools?

Knife and fork moved the cutting onto the plate, where before diners clamped meat in their teeth and sliced off a piece. Among Chinese diners, Brace linked the same change to chopsticks, 900 years earlier.

Which word do orthodontists use for the tendency of straightened teeth to drift back out of line?

Relapse is a lifelong risk, driven by the recoil of stretched fibres around the roots, pressure from the surrounding soft tissues and continued growth. A holding appliance after braces guards against it.

Norman Kingsley, a 19th-century pioneer of orthodontics, also practised which art form?

Sculpture sat alongside writing among Kingsley's talents. His soft-rubber artificial palates let patients born with a cleft palate speak and eat normally.

Dentists chart the mouth in upper and lower, left and right sections, each known as what?

A quadrant is one quarter of the full set of teeth. When a tooth is to be pulled, dentists may write it in two notations at once, so the wrong one is less likely to come out.

In the tooth numbering used by US dentists, which numbers mark the two upper front teeth?

8 and 9 fall in the middle because the count starts at the upper right wisdom tooth and runs across to the upper left. Dentists in most other countries use a different, two-digit code.

After the upper row, the numbering used by US dentists resumes on the bottom jaw at which position?

Lower left wisdom tooth is number 17, because the count drops directly down from where the top row ended. It then runs back along the bottom jaw to finish at the lower right.

In the chart used by US dentists, adult teeth get numbers while a child's first teeth get what?

Capital letters run from A at the upper right round to T at the lower right. Every tooth, in either set, therefore carries a label that no other tooth shares.

The American Dental Association dropped Palmer notation because its symbols were awkward on what?

Keyboards could not produce Palmer's corner-bracket marks, so in 1968 the association backed a chart of plain numbers and letters instead. It had recommended the Palmer method as recently as 1947.

In two-digit FDI dental notation, what does a first digit from 5 to 8 always signal?

A baby tooth takes a first digit from 5 to 8, while the four sections of adult teeth use 1 to 4. The scheme was developed by the FDI World Dental Federation and is used in most countries.

Palmer's corner-bracket tooth notation outlasted newer codes among dentists in which country?

United Kingdom orthodontists, students and practitioners still overwhelmingly preferred it in 1998, long after most of the world had adopted a two-digit code. It is named for Ohio dentist Corydon Palmer.

Palmer notation counts teeth outward from the midline, so every wisdom tooth gets which number?

8 marks all four wisdom teeth on a Palmer chart, since each corner of the mouth is counted separately, starting from 1 at the front. A small corner bracket beside the number shows which corner is meant.

FDI codes open with a digit for the mouth corner, so which code marks the upper right front tooth?

11 joins a 1 for the patient's upper right with a 1 for the tooth nearest the midline. The system is also published as an international standard, ISO 3950.

Dental charts are drawn from the dentist's viewpoint, so a patient's right appears on which side?

The left of the chart shows the patient's right, just as a dentist sees it when facing the chair. Labels such as 'upper right' always refer to the patient's own right.

Which mild, reversible form of gum disease causes redness and bleeding but no loss of bone?

Gingivitis clears up with good oral hygiene, but left untreated it can progress to periodontitis, in which the tissue and bone around the teeth are destroyed.

Which habit is a major risk factor for periodontitis, tied in studies to more bone and tooth loss?

Tobacco smoking not only raises the odds of gum disease but can also interfere with its treatment. Quitting has been shown to improve the health of the gums.

Which chronic condition raises the risk of gum disease and is in turn made harder to control by it?

Diabetes and gum disease feed each other, because the constant inflammation from infected gums makes blood glucose harder to balance.

Which dental specialist treats disease of the gums and supporting bone and also places implants?

Periodontist comes from Greek words meaning 'around' and 'tooth', a nod to the supporting structures the specialty studies.

The phrase 'long in the tooth', meaning old, refers to the receding gums of which ageing animals?

Horses are thought to be the source, since their gums recede with age and make the teeth look longer. Their teeth are such a good guide to age that inspecting a gift horse's mouth was considered rude.

Advanced gum disease loosens teeth by slowly eating away which structure that holds their roots?

Alveolar bone forms the sockets that anchor the teeth, and its loss to periodontitis is essentially irreversible. Gum disease is considered the main cause of tooth loss in adults worldwide.

Dentists track periodontitis with a blunt probe that measures the depth of what around each tooth?

Gum pockets deeper than about 3 mm suggest that the gum's attachment to the tooth is being lost. The 'deep' in a deep cleaning refers to them.

Which non-surgical treatment for gum disease is popularly known as a deep cleaning?

Scaling and root planing first scrapes hardened deposits from below the gumline, then smooths the exposed root surfaces. An ordinary cleaning skips that second step.

Which mouthwash antiseptic eases mild gum inflammation but can stain teeth after four weeks of use?

Chlorhexidine also turns up in skin disinfectants, wound dressings and eye drops. Newer rinses add chelated zinc so that they stain less.

Gum disease was once known as Riggs' disease after John Riggs, dentist to which American author?

Mark Twain was a patient of Riggs in Hartford, where the dentist was the first to limit his practice to treating the gums. Riggs scraped deposits from the teeth with instruments he designed himself.

George Washington's dentist John Greenwood built the first dental foot engine from his mother's what?

Spinning wheel treadles already turned a wheel by foot, so Greenwood adapted his mother's to rotate a drill. His father, Isaac Greenwood, was a dentist too.

Which jaw muscle, found only in mammals, is the most obvious of the four muscles used for chewing?

The masseter is one of the strongest chewing muscles and lies closest to the surface. It is particularly powerful in herbivores, which need it to grind plant matter.