140 Fun Facts About Dental & Dentist

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

They split evenly, 16 in the upper jaw and 16 in the lower, and the count includes four wisdom teeth that many people never fully grow.

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

Ten sit in the upper jaw and ten in the lower, and there are no premolars in the set at all - the baby molars are later replaced by premolars.

Which is the hardest substance in the human body?

It rates about 5 on the Mohs scale, between steel and titanium, yet it is as brittle as glass and never regrows once lost.

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

Patients usually just call it 'the nerve', and it is what a root canal removes.

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

It is yellow-hued and porous, softer than enamel, and it keeps forming slowly throughout life.

Which type of tooth is designed mainly for tearing food?

Incisors cut, molars grind, and the pointed teeth on either side of the incisors do the tearing - the same job they do far more dramatically in a dog.

Premolars are also known by what other name?

The name refers to their two cusps, or points; molars have four or five.

Wisdom teeth are formally known as which teeth?

They got the nickname because they arrive so late, when a person is presumably wiser, probably as a translation of the Latin dens sapientiae.

According to a 2024 survey, roughly what share of Americans had had their wisdom teeth removed?

Among 18-to-29-year-olds the figure was only 26%, partly because some dentists have stopped recommending routine extractions.

Impacted wisdom teeth became roughly ten times more common after which historical shift?

Soft, processed food meant less chewing stress, so jaws grew shorter and wider and ran out of room for the last molars.

Which bacterium is most closely associated with tooth decay?

It feeds on sugars and excretes lactic acid, which is what actually dissolves the enamel; the bacteria live in the biofilm we call plaque.

The word 'caries', the medical name for tooth decay, comes from a Latin word meaning what?

As of 2016 roughly 3.6 billion people, nearly half the planet, had it in their permanent teeth.

An ancient Sumerian text blamed cavities on what?

The same idea shows up in ancient India, Egypt, Japan and China, and the surgeon Guy de Chauliac was still promoting it in the 14th century.

Which 18th-century BC Babylonian law collection mentions pulling teeth as a punishment?

It refers to extraction twice; meanwhile the Edwin Smith Papyrus from Egypt was discussing how to treat broken jaws.

Hesy-Ra, an official under the pharaoh Djoser, holds what distinction in dental history?

His title Wer-ibehsenjw translates either as 'Great one of the ivory cutters' or 'Great one of the dentists', which is a lot of hedging for one job description.

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

He adapted tools from watchmakers, jewelers and barbers, and blamed sugar acids for decay a century and a half before germ theory.

Before dentistry was a profession, tooth-pullers used an imprecise tool named after which bird?

They often took healthy teeth along with the bad one, and sometimes part of the jaw.

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

Cincinnati's Ohio College of Dental Surgery followed in 1845, and it was that school that later admitted the first woman dental graduate.

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

She had been refused admission twice for being a woman, so she simply opened her own practice in 1861 and was admitted as a senior once the ban was lifted.

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

He never patented it, believing freedom from pain should be 'as free as the air we breathe', and his own student William Morton later took the credit with ether.

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

His partner John Riggs did the pulling, and Wells declared afterward that he had not felt it 'so much as the prick of a pin'.

George Washington's dentures were famously NOT made of wood. Which material was actually among them?

Ivory stains quickly, which may be how the wooden-teeth myth started; textbooks repeated it well into the 20th century.

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

The survivor was a premolar, and he later 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?

The body was Joseph Warren's, dug up nine months after Bunker Hill; it is often cited as the first forensic dental identification in America.

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

The Romans probably borrowed the technique by the 5th century BC; porcelain dentures did not arrive until around 1770.

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

Results published in 1950 showed a big drop in cavities; the whole idea grew out of a 30-year hunt for the cause of the 'Colorado brown stain'.

Dentist Frederick McKay spent 30 years investigating a mottled-tooth condition known by what name?

The stained teeth were oddly cavity-free, and an Alcoa chemist eventually found fluoride in the local water was the common factor.

In 2015, what fluoride level did the US recommend for community drinking water?

Older guidance from 1962 allowed up to 1.2 mg/L in cooler climates, on the theory that people in hot places drink more water; the 2015 figure was 0.7 mg/L.

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

Before nylon, bristles were usually Siberian boar hair, which held bacteria, dried badly and fell out.

The first electric toothbrush, the Broxodent, was invented in 1954 in which country?

Studies since have found powered brushes about equal to good manual brushing, with perhaps a little less plaque and gingivitis.

What was the toothbrush's ancestor, a frayed twig found in Sumerian sites from 3500 BC?

One end brushed and the other end served as a toothpick; the miswak version is still used before prayer across the Islamic world.

In the US, daily tooth brushing did not become routine until after which event?

Soldiers were required to clean their teeth every day and brought the habit home; the first US toothbrush patent had been granted back in 1857.

Dr. Washington Sheffield put toothpaste in a collapsible tube in 1880 after his son saw what in Paris?

Colgate copied the idea in 1896; the original tubes were made of lead.

Ancient Egyptian tooth powder from around 5000 BC included powdered ashes of what?

The recipe also called for pumice, burnt eggshells and myrrh; the Greeks and Romans later added crushed bones and oyster shells for grit.

Under what brand name did Unilever market Leonard Marraffino's 1955 striped toothpaste?

It grabbed 8% of the US market in its second year and never reached that share again; the Signal brand followed in Europe in 1965.

Nylon dental floss was developed during World War II by which physician?

Nylon beat silk because it resisted abrasion and could be made in long lengths; flossing only became a daily North American habit in the 1970s.

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

Fones opened the first school for the profession in 1913, and Newman received the first license in 1917.

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

Periodontics is gums and implants, and prosthodontics is dentures and bridges.

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

Before Angle nobody had thought of attaching an appliance to each individual tooth; orthodontics went on to become the first recognized dental specialty.

After braces come off, how long do most patients wear a retainer full-time before nights only?

The braces themselves usually stay on for one to three years, depending on how far the teeth have to travel.

The earliest known written record of the tooth fairy is a 1908 'Household Hints' item in which newspaper?

It advised mothers to stock up at the 5-cent counter; by 2023 the average US payout per tooth had reached $6.23.

In Spain and much of Latin America, which animal takes the place of the tooth fairy?

Ratoncito Pérez was written up in 1894 for the eight-year-old King Alfonso XIII, who had just lost a tooth, and Madrid gave the mouse a commemorative plaque in 2003.

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

Her feast day is 9 February, and in parts of Italy she even fills the tooth-fairy role, collecting children's baby teeth.

Sharks continually shed and regrow teeth. Roughly how many can some species go through in a lifetime?

Pliny the Elder thought fossil shark teeth fell from the sky during lunar eclipses; Nicolaus Steno set the record straight in 1667.

The narwhal's spiral tusk is actually what?

It projects from the left side of the upper jaw, grows up to 3 meters, and its scientific name Monodon monoceros means 'single-tooth single-horn'.

In which order of animals do the incisors keep growing throughout life, forcing them to gnaw constantly?

Elephants, kangaroos and manatees are odd in another way: unlike humans they are polyphyodonts, replacing teeth repeatedly rather than just once.

How many teeth are in a full set of adult human teeth?

That includes the four wisdom teeth, which many people have removed or never grow at all.

How many baby teeth does a child usually get?

They start forming in the embryo at six to eight weeks and begin poking through around six months after birth.

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

The ameloblast cells that build enamel are destroyed once the tooth erupts, so a cavity is permanent until a dentist fills it.

How many molars, including wisdom teeth, does a full adult mouth contain?

The rest of the set is eight incisors, four canines and eight premolars.

Wisdom teeth are the third molars. Between what ages do they usually come through?

The Latin name is dens sapientiae, and they are the most commonly impacted teeth in the mouth.

Which human teeth have the longest roots?

Canines are also the only teeth with a single cusp, and they are nicknamed eye teeth because they sit beneath the eyes.

Canine teeth are named for being especially prominent in which animal?

Humans have four; in many species the males' are far larger and used for display and fighting.

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

The French call them dents du bonheur, lucky teeth, and in Nigeria and Ghana the gap is considered attractive.

Below what pH does mouth acid begin dissolving a tooth's outer mineral layer?

The bacterium Streptococcus mutans turns sugar into lactic acid, which is why sweets and decay go together.

Which bacterium is the main culprit behind tooth decay?

As of 2016 roughly 3.6 billion people, almost half the planet, had cavities in their permanent teeth.

In medieval Europe, narwhal tusks were sold as what?

At the peak of the trade a tusk could fetch hundreds of times its weight in gold.

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

They sit in rows like a conveyor belt, and some shark species shed around 35,000 teeth in a lifetime.

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

Fossil collectors pay steep prices for them; Dunkleosteus was an armoured fish with bony blades rather than teeth.

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

It is made of chitin and works like a rasp; limpet versions contain iron and rank among the strongest biological materials known.

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

Clams and oysters filter-feed with cilia instead of scraping.

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

They are the second upper incisors; about a third of each tusk is hidden in the skull, and they keep growing around 17 cm a year for life.

How many sets of molars does an elephant go through in its lifetime?

New sets move in from the back; once the last set wears down in an elephant's forties, it can starve.

What defines a rodent's teeth?

The word rodent comes from the Latin rodere, to gnaw, which they must do constantly to keep the incisors short.

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

The softer dentine behind wears away faster, leaving a chisel edge without any effort.

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

It is born with incisors and canines that fall out and are never replaced, leaving only cheek teeth that regrow continuously.

How often can a crocodile replace each of its roughly 80 teeth over its lifetime?

A small replacement tooth waits beside every full-grown one; unlike an alligator, all its teeth show when the mouth is shut.

How long can a hippopotamus's lower canine teeth grow?

The jaw hinge sits so far back that a hippo can open its mouth to 100 to 110 degrees.

What does a giraffe have instead of upper front teeth?

It strips leaves with a 45 cm dark tongue instead, which may be dark to protect against sunburn.

For thousands of years, what did people in Sumer, Egypt, India and China believe caused toothache?

The idea only died out after early microscopists went looking and found nothing.

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

Stone-age dentists at Mehrgarh in what is now Pakistan were drilling teeth with bow drills around 7000 BC.

The first named dentist in history, Hesy-Ra, practised in the 27th century BC in which civilisation?

During the Middle Ages the job passed to barber-surgeons, who mostly just pulled teeth.

What were George Washington's dentures made from?

The wooden myth probably arose because the ivory stained brown; he had one natural tooth left at his 1789 inauguration.

The Etruscans made partial dentures by fastening teeth together with bands of what?

Porcelain false teeth arrived around 1770 and hardened-rubber vulcanite bases in the 1850s.

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

The idea grew out of Frederick McKay's study of the "Colorado brown stain", whose sufferers had oddly cavity-free teeth.

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

That was during the Tang dynasty; before that, people in Sumer used frayed twigs called chew sticks as far back as 3500 BC.

In a 2003 MIT survey, which everyday invention did Americans say they could least live without?

It beat the car, the computer and the phone.

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

The tube itself was inspired by paint tubes and invented by dentist Washington Sheffield in 1880.

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

Procter & Gamble developed it in the 1950s with researcher Joseph Muhler at Indiana University.

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

Johnson & Johnson patented floss in 1898 using suture silk; nylon took over during World War II.

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

"I didn't feel it so much as the prick of a pin," he said; his Boston demonstration a month 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?

The little mouse was invented in 1894 by Luis Coloma in a story for the eight-year-old King Alfonso XIII.

The earliest known tooth fairy mention appeared in 1908 in which newspaper's hints column?

A 1927 play by Esther Watkins Arnold gave her the elf-like form kids picture today.

According to Delta Dental's survey, what did the tooth fairy pay per tooth in the US in 1998?

The going rate peaked at $6.23 in 2023 before slipping to about $5 in 2024-25.

Who identified Joseph Warren's body in 1776 by a dental prosthesis he had made, America's first forensic dental ID?

The silversmith made false teeth on the side; teeth remain useful to forensics because they survive fire and decomposition.

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

The National Academy of Sciences and others have since concluded bite marks cannot reliably identify a person.

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

The nickel-titanium alloy has shape memory; orthodontist George Andreasen started using it in 1979.

Orthodontics is the dental specialty that deals with what?

Its sister field, dentofacial orthopedics, aims to guide facial growth itself, and worldwide malocclusion prevalence has been put as high as 56%.

Which 'father of American orthodontics' founded the first school of orthodontia in St. Louis in 1900?

His 1899 classification of bites into Class I, II and III is still the standard shorthand in every orthodontist's notes.

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

Class II is the overbite/overjet family, and Class I means the molars meet normally but the other teeth are crowded or spaced.

Which 18th-century French dentist, credited with founding orthodontics, straightened teeth with an iron 'bandeau'?

His 1728 book The Surgeon Dentist described the methods; the bandeau helped expand the palate.

Which ancient people buried their dead wearing dental appliances for the afterlife?

Around 400–300 BC, Hippocrates and Aristotle were already musing about ways to straighten teeth.

Lingual braces, invented by Craven Kurz in 1976, are fixed to which surface of the teeth?

Their whole appeal is near-invisibility; the trade-off is a tongue that takes a while to get used to them.

Invisalign's clear aligners are made by which company, founded in 1997?

Founder Zia Chishti had the idea while wearing a retainer as an adult patient, and was ousted from the company in 2002.

Where did Zia Chishti get the idea for Invisalign?

He reasoned that a series of small retainer-like devices could add up to one large movement.

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

Vacuum-formed clear retainers are the modern alternative; the wire keeps the anterior teeth from drifting back.

Orthodontic headgear differs from braces in what obvious way?

Straps around the head or neck anchor it; it's usually reserved for bites that are severely out of line.

Who published the first paper on palatal expansion, in the journal Dental Cosmos in 1860?

The president of the American Dental Association at the time opposed the idea of widening the arch.

A gap between two teeth, famously sported by Madonna and Elton John, is called what?

The word is Greek for 'space', and many mammals have one as a normal feature between incisors and molars.

According to orthodontists, why are crowded, misaligned teeth so common in modern humans?

Less fresh fruit and vegetables and more soft food mean jaws that don't grow big enough for all 32 teeth.

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

Per-Ingvar Brånemark placed the first titanium implant in a human volunteer in 1965.

In what year did Brånemark place his first titanium dental implant in a human?

The recipient, Gösta Larsson, was the first person to receive a modern dental implant.

Which chemist created procaine in 1905 and gave it the trade name Novocain?

The name combines Latin nov- ('new') with -caine, the usual ending for anesthetic alkaloids.

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

Chemist Nils Löfgren's team made it the first amino amide-type local anesthetic.

Listerine mouthwash was named after which pioneer of antiseptic surgery?

Chemist Joseph Lawrence developed it in 1879; it only boomed in the 1920s as a cure for 'chronic halitosis'.

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

Halitosis was then an obscure medical term for bad breath.

Which German dentist made one of the first intra-oral dental X-rays in January 1896?

He improvised the setup in Braunschweig within weeks of Röntgen's discovery.

Gunfighter Doc Holliday earned his dental degree at age 20 from a college in which city?

He briefly practised in Griffin, Georgia before tuberculosis and the frontier intervened.

Western novelist Zane Grey opened a practice in which profession in New York City in 1896?

He practised as Dr. Zane Grey before turning to writing.

Dental amalgam fillings are an alloy of which liquid metal?

It is mixed with particles of silver, copper or tin; a Ming dynasty text of 1505 gave an early recipe.

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

It is usually paired with a zinc oxide eugenol-based cement.

What percentage of tooth enamel is mineral, the highest of any body tissue?

The main mineral is hydroxyapatite, a crystalline calcium phosphate.

What is the primary mineral in tooth enamel?

It is a crystalline form of calcium phosphate.

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

Its global prevalence, awake and asleep, is roughly 22%.

The word 'halitosis' combines a Greek suffix with a Latin word meaning what?

'Halitus' plus '-osis', meaning a diseased condition.

Tartar, which only a professional cleaning can remove, is a hardened form of what?

Once mineralised it can only be removed professionally.

What gives a beaver's incisors their orange colour?

The thick, iron-hardened enamel keeps their ever-growing teeth strong.

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

It is the same protein found in hair and fingernails.

About how long were the upper canines of the largest Smilodon species?

They were slender and fragile, adapted for precision killing rather than crushing.

In what year was the American Dental Association, the world's largest and oldest, established?

It now has more than 159,000 members.

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

He drills into Babe's teeth without anesthetic while asking 'Is it safe?'

Who plays sadistic, nitrous-addicted dentist Orin Scrivello in Little Shop of Horrors (1986)?

Orin is florist Audrey's abusive boyfriend and gets his own song, 'Dentist!'

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

It is toxic to dogs and ferrets; Emil Fischer isolated it from beech chips in 1890.

Who is believed to have made the first mass-produced toothbrush, in Britain in 1780?

He hit on the idea in prison, deciding a rag with soot and salt was ineffective.

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

Primary teeth keep arriving until about 25 to 33 months.

Which of these mammals grows more than two sets of teeth, unlike humans?

Kangaroos and manatees are also polyphyodonts.

As of 2016, roughly what share of the world's population had cavities in their permanent teeth?

That is about 3.6 billion people.

Who made the first porcelain dentures, around 1770?

Porcelain replaced ivory and human teeth as a denture material.

The oral irrigator maker Waterpik began in 1962 under what corporate name?

It is based in Fort Collins, Colorado, and is now a Church & Dwight subsidiary.

Hominin remains bearing 'toothpick' lesions from about 1.8 million years ago were found in which country?

The toothpick is the oldest dental-cleaning instrument; a Neanderthal jaw from Spain shows one used to ease gum pain.

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

Romans 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?

Skilled bead craftsmen may have operated the drills, cutting cavities 3.5 mm deep with concentric grooves.

In which year was the first electric dental drill patented?

By 1914 electric drills reached 3,000 rpm; modern air-turbine handpieces spin at up to 420,000 rpm.

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

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?

It may be delivered as carbamide peroxide, a stable complex that releases the bleach on contact with water.

In which sport did the mouthguard originate?

Early boxers clenched cotton, sponge or bits of wood until British dentist Woolf Krause began making proper mouthpieces.

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

It was a big improvement on the thick guards boxers wore and was molded to fit over the upper or lower teeth.

From the 1850s, dentures were made of Vulcanite, a form of what material?

Porcelain teeth were set into it; the 20th century brought acrylic resin, still the main denture material today.

Which two bacteria are named as harmful residents of the plaque behind gum disease?

Gum disease is regarded as the main cause of tooth loss in adults worldwide, affecting an estimated 538 million people in 2015.

In which US state did Alfred Fones open the first school for dental hygienists in 1913?

His cousin Irene Newman, trained in 1906, received the world's first dental hygienist licence there in 1917.