So here are some of the interesting facts about the techniques and the sort of myths in dentistry.

• Horses teeth are extremely long and grow continuously. They wear down, change shape and become discolored as they grow, so we can really tell a horse’s age by looking at its teeth.
• Long ago, people used to ground up chalk or charcoal, lemon juice, ashes or even a mixture of tobacco and honey to clean their teeth. It was only about 100 years ago that someone finally created a minty cream to clean their teeth and it came to be known as Toothpaste.
• China sets aside September 20^th as a national holiday known as “Love your teeth day”
• Before toothbrushes were invented people used twigs or their fingers to brush their teeth.(Neem twigs are still used in India as thy have high bactericidal property)
• Some Interesting facts about toothpastes:
• The Greek physician Hippocrates (400BC) suggested a toothpaste made from three mice and the head of a hare to cure toothache.
•  Before toothpaste was invented people used dry, rough things as an abrasive to clean their teeth – like crushed eggshell, pumice or the burnt hooves of animals!
•   A third of the population squeeze their toothpaste tube from the middle.
•   The world’s oldest-known formula for toothpaste, used more than 1,500 years before Colgate began marketing in 1873, was discovered on a piece of dusty papyrus in the basement of a Viennese museum.
• In early 1600 Japanese women made their teeth black to show loyalty to their husbands.
• In roman times, the ancient Gauls, as well as other people, used Urine (which contained Urea) as a mouth rinse to whiten their teeth.
• The Ancient Greeks were the first to discover and use Pliers to extract teeth.
• The ancient Chinese wrapped tiny pieces of parchment around painful teeth, all of which contained written prayers and incantations.
• Aztec dentists used to mix Iron fillings, water and navel lint bake and insert into the cavities to seal it.
• In the old days when dentures weren’t invented yet, dentists would do a quick surgery in implanting teeth in the mouth a person, by obtaining the teeth from a dead persons mouth.
• William F. Semple a dentist from Mount Vernon, Ohm was issued the first patent in 1869 for chewing gum.
• The Electric chair was invented  by a Dentist.
• The rat’s teeth keep growing constantly all through their lives, that is the reason why they bite into everything they see to get rid of the itching sensation in their gums.
• The biggest shark species has the smallest teeth. The 12 meter ling whale shark has more than 4,000 teeth, wach only 3mm ling. New teeth are constantly being formed in rows in a sharks jaw. Shark’s teeth are normally replaced every eight days. A shark’s teeth are literally as hard as Steel.
• Cows do not have upper front teeth and their lower bottom one’s never stop growing.
• A third of the population squeeze their toothpaste tube from the middle.
• Before toothpaste was invented people used to dry, rough things as an abrasive to clean their teeth – Crushed eggshell, Pumice or the brunt hooves of animals.
• The Greek physician Hippocrates (400BC) suggested a toothpaste made from Three mice and the head of a hare to cure toothache.
• Before toothbrushes were invented people used twigs to brush their teeth. (Neem twigs were used in India as they have high Bactericidal property, Charcoal is also used in some rural areas)
• Diet sodas are just as damaging as regular sodas at weakening tooth enamel.
• Aadvark teeth have no enamel coating and are worn away and regrown continuously.

Some Interesting facts about teeth:

• It  is a weird belief that those who smile in school yearbook photos are more likely to have a successful career and marriage that those with dull or lifeless faces.

  

• The most valuable tooth was that of Sir Issac Newton purchased by a Businessman for $4560. Which he used as a ring.
• A couple of hundred years ago bad teeth were considered to be a rich man’s disease. It was only the rich people who could afford to eat sweet things like Queen Elizabeth I, who had very bad teeth.

•  In the dark ages, superstitions held that a person could cure his/her toothache or re-grow a lost tooth by obtaining a tooth from someone else. This tooth would have  preferably come from a  hanged criminal. It was believed that just the mere possession of such a tooth would work.
•  Cows do not have upper front teeth and their bottom ones never stop growing!
• In the 18th century people would sell their teeth to the rich people, Who then used to make false teeth with them.(so replacement of teeth was seen from as early as 18th century)
• The biggest shark species has the smallest teeth. The 12 metre long whale shark has more than 4,000 teeth, each only 3mm long.
• New teeth are constantly being formed in rows in a shark’s jaw. Shark’s teeth are normally replaced every eight days.
• The rats front teeth are constantly growing all through its life, this is the reason they bite into everything they see to get rid of the itching sensation due to growth of teeth.
• Over 40%-50% of children will be affected by tooth decay before they reach 5years of age.
• According to the May 2000 Surgeon General’s report, Oral health in America, more than 51 million school hours are lost due to Dental related problems.
• Kids laugh around 400 times per day compared to the mere 15 times a day by grown ups.
• 38.5 days is the number of days a person spends brushing his teeth in his whole lifetime.
• According to a poll conducted 73% of people would rather go for grocery shopping rather than Floss his/her teeth.
• While 9 million children in this nation do not have medical insurance, more than twice that number – 23 million- don not have dental insurance.
• Of the 4 million children born each year, more than half will have cavities by the time they reach second grade.
• For 25% of children the first visit to the emergency ward in hospitals is due to a Dental related problem.

While going through some websites i came across this list of cures for tooth problems which were used in ancient times,

The following disgusting list are other cures for tooth problems in the past.

•      Toothache: apply the following  mixture to the corresponding shoulder: figs, saffron, mustard seed, and plaster of myrrh; boil earthworms in oil and drop the oil into the ear holes; rub the tooth with dried cow’s dung!
•      Tooth decay: rinse with a mouthwash made by boiling dogs’ teeth in wine.
•      To make loose teeth firm, tie a frog to your jaw.

 Important Message- please do not try these at home!

 Tooth fairy: Many people tell their children that when we loose our teeth/tooth, and when placed under our pillow before we sleep a tooth fairy comes and exchanges the tooth with a gift.

The pain or the stinging sensation seen on the teeth is due to the dentin which makes up the bulk of the tooth, and is a living tissue, it contains Odontoblastic processes which arise from the Pulp and are considered to be the main transporter of pain.

Some of the most accepted theories are:

1) Direct Neural stimulation theory

2) Transduction theory

3) Hydrodynamic theory

Now let us get to know about each of these theories briefly.

1) Direct neural stimulation theory: According to this theory the stimuli reaches the nerve endings in the inner dentin. But how it reaches the nerve endings could not be explained. Due to little scientific proof it is not accepted now.

2) Transduction theory: According to this theory, the Odontoblastic processes are excited by the stimulus and transmit the impulses to the nerve endings. This theory is also of little importance as it has been noticed that there are no neurotransmitters in the dentin.

3) Hydrodynamic theory: This theory is also known as ‘Fluid theory’, According to this theory the harmful stimuli such as heat, cold, air blast, mechanical pressure. . etc cause some changes in the fluid movement in the dentinal tubules either inwards or outwards which causes some mechanical disturbances due to mechanoreceptors present at the nerve endings, which stimulates the pain mechanism.

It is defined as the deposition of the mineral salts in and around the organic matrix to make it a calcified structure.

The mineralization process is based on 2 mechanisms:

1. Booster Mechanism
2. Seeding mechanism

And it is explained with the help of 3 Theories:

1. Booster Theory
2. Seeding Theory
3. Matrix Vesicle Theory

The theories explain the process of mineralization in different ways, so lets know about them:

Boosters Mechanism: According to this theory due to the concentration/action of the enzymes the concentration of the calcium and phosphate ions which are building stones of mineralization increases to such a level that would lead to their precipitation.

Seeding Mechanism: It refers to a presence of a seeding or nucleating substance which acts a mould (or) template on which the crystals are deposited, the seeding substance resemble apatite crystals.

Matrix Vesicle  theory: This theory states that, due to the presence of vesicles containing apatite crystals near each cartilage cell which aggregate and form a matrix which is mineralized. 

Now going into the details of each Mechanism:

Booster Mechanism: There are 2 theories which explain this mechanism of mineralization

Robinson’s Phosphatase theory: According to him the presence of alkaline phosphatase releases the ions which take part mineralization and increases their concentration to such a level that their precipitation is seen.

Objections: As alkaline phosphatase is present even in tissues which do not calcify.

Cartier’s theory: According to him there are 2 types of substances which inhibit and one which induce the process, so with proper control of their concentrations the mineralization takes place.

Inducer: Adenosine triphosphate

Inhibitor: Pyrophosphates

Seeding Theory : It was made on account of the shortcomings of the booster theory, and the experimental studies revealed collagen to act as a seed, with apetite crystals forming on the collagen fibers.

The possible seeding substances are:

1. Collagen
2. Chondroitin sulphate
3. Phosphoproteins

Matrix Vesicle Theory: According to this theory, due to the presence of vesicles containing apatite crystals near each cartilage cell which aggregate and form a matrix which is mineralized.

There are 2 types of vesicles:

Type I Vesicles: These are substances extruded from the cartilage cells.

                              Cause breakdown of proteoglycans and GAG.

Type II Vesicles: These are detached pieces of cartilage cells, are bounded by trilamellar   membrane.

                                Promote mineralization by a blend of booster and seeding mechanisms.

The anterior teeth or the incisors mainly the mandibular erupt lingually to that of the deciduous, and the posteriors which are the Premolars erupt from below the deciduous molars which are the predecessors of the Permanent premolars.

The Permanent teeth dissolve the roots of the Deciduous teeth with the help of cells called osteoclasts which dissolve the dentin and the pulp of the root and as the Permanent teeth erupt push the Deciduous teeth out of the alveolar bone sockets.

The sequence of eruption of the permanent teeth is different in the mandible and the maxilla, the change seen due to the canine.

Maxilla: I Molar-Central incisor-Lateral Incisor-I,II Premolar-Canine-II Molar-III Molar.
Mandible: I Molar-Central Incisor-Lateral Incisor-Canine-I,II Premolar-Canine-II Molar-III Molar.

The development of tooth can be considered in 2 stages

Formation of crown and root

Eruption of the tooth

The sequence of eruption of primary teeth is based on their development, it is as follows

Central incisor(A) followed by Lateral incisor(B) followed by First Molar(C) followed by Canine(D) and the last Second Molar(E).

A->B->C->D->E->F.

If the sequence of eruption and the ‘fall out’ of the teeth are in the same order.