Essentially, the definition of tooth and teeth disease is anything which causes teeth to be malformed or suffer increasing damage in some way, over a period of time.  So tooth and teeth diseases can be caused by genes or the environment.  The key to the definition is that it is a process that occurs over time.

Tooth and teeth disease has been around since ancient times. From autopsies of Egyptian mummies, we know that some of the ancient Egyptians died agonizing slow deaths because of uncontrolled tooth disease / decay. Some mummies had all their teeth and jaws infected by tooth disease.

In the 1700's and 1800's we know from published cartoons that toothache was around and was treated often by blacksmiths and, often in public, even on public stages in front of large audiences.

In the late 1800's early 1900's, America was known as having the highest rates of tooth and teeth disease anywhere in the world. The cause of the high rate of tooth and teeth disease was attributed to the highly refined foods that Americans were eating.

The refined foods introduced higher concentrations of substances into the food supply, especially acidic types, which eat away / erode the tooth enamel.

It is clear, that even in the 1800's, the importance of diet in causing tooth and teeth diseases was well known.

This knowledge of tooth and teeth diseases continues to be verified to this day. When soft drinks became widely available, tooth disease increased quite markedly. Soft drink contains both sugar and acid which can quickly breakthrough the enamel of teeth, via causing plaque and acid erosion, allowing disease to enter the teeth.

  Acid, of course, eats through things, including teeth.

To explain the relationship between plaque and tooth disease:

  The definition of plaque is a sticky mass of germs that stick to the teeth.  The germs are bacteria, that are normally found in the mouth, but it is the plaque bacteria that causes much of the tooth disease associated with tooth decay.

  When we eat or drink sugary or starchy things, the plaque builds up and spreads more quickly over the teeth, thriving on the sugary and starchy remains on the teeth, causing more damage.

  Plaque that is less than 12 hours old causes little or no teeth disease, as the bacteria have normally not bred up enough in population on the teeth to do damage - which is why it is suggested that brushing teeth occurs in the morning after breakfast and at night before bed.

  Plaque that is left on the the teeth for days normally builds up a heavy growth of disease causing bacteria which can start to seriously disease the teeth. The denser the plaque becomes - the more denser the population of the bacteria in other words - the more likely the bacteria right on the teeth will start producing acid byproducts, as the air isn't present to them to metabolize normally. 

If left long enough, the plaque hardens into tartar which can create a layer of disease carrying germs concentrated on the teeth and on the gums, which can then cause tooth and or gum disease, such as gingivitis, an early stage of periodontal disease (gum disease) in which the gum bleeds easily and is swollen.  If left untreated this gum disease will cause all your teeth to become diseased and fall out.

Eating little bits at a time also assists plaque causing disease to our teeth, as less saliva is produced to control the plaque build up.

Further, if teeth are NOT cleaned properly, food remains between the teeth and, as it decomposes on the tooth it generates acid which then decays the teeth - not a pleasant disease process, as the odors given off by decomposing food is not very nice.  Also, leaving food in the teeth assists plaque growth no end and is a leading cause of perodontal disease.

Another term you will hear about is calculus or scale. I recently clarified much of my understanding with a dental specialist recently, so can now clarify the modern definition of these as used in dental practices.  Calculus and scale are the same thing and are also a leading cause of tooth disease.  The calcium comes out of the saliva - which is calcium rich - and deposits on the teeth, it is this deposit on the teeth that is called scale or calculus - that's the definition.  In itself, the calcium is not a disease process, but what happens is that the bacteria underneath the scale can NOT be cleaned off by normal teeth cleaning, as it is protected by the scale, so the bacteria can build up and decay the teeth. 

A Popular Myth of Tooth Disease:

If you keep your teeth perfectly clean, eat and drink appropriately, use fluoridated tooth paste three times a day, drink fluoridated water, floss your teeth after eating and rinse with mouth wash, tooth decay wont happen.

This is a myth. Some people do go to these extremes in trying to prevent tooth disease, but still end up with tooth decay, toothache, tooth abscess and the need to have fillings and crowns on teeth. Employing such stringent hygiene measures against tooth decay may certainly help reduce the amount and frequency of tooth disease, but it wont put an end to tooth disease.

Also, even though the above stringent tooth hygiene measures may be taken, fact is, it's impossible to completely clean teeth.

Physical Trauma is Another Cause of Tooth and Teeth Disease:

Physical trauma of the tooth, such as by the accidental damage that may be caused in playing sports, or biting on something hard like an ice cube, where a tooth or teeth may fracture or get chipped, can lead to diseases of the teeth.

The reason for this increasing the risk of tooth disease, is that while the tooth enamel is intact, the tooth is very impervious to a disease processes starting, but any physical trauma that damages the enamel coating, gives tooth disease the chance to get through and attack the softer tooth beneath.

Also, anything that is really sticky, like hard toffees, can grip hold of crowns, fillings, baby teeth or a loose tooth and cause them to be pulled right out - using the power of your own jaw to do it.  This damage then allows germs and debris to enter, or the jaw to possibly shrink, starting a new disease process off in the jaw, in the tooth or in the teeth.

The Importance of Looking after Baby Teeth to Help Prevent or Reduce Tooth Disease in Adults:

THE TEETH DISEASES and IRREGULARITY OF TEETH - Another perspective on the importance of baby teeth.

Today's Perspective on Tooth Disease and the Development of the Teeth:

In today's perspective, genetics is considered one of the main reason for teeth irregularity in adults, with other causes including trauma to the jaw, other diseases ( including decay ) of the the teeth, premature loss of baby teeth, premature loss of adult teeth, thumb sucking and or tongue thrusting.

Certainly, in individuals with Down Syndrome, irregularity of the tooth and teeth is quite common and it is put down to genetics. Most dentists we have visited, place the emphasis very much on genetics, particularly as diseases that might affect tooth development are not that common, apart from the disease process of tooth decay and gum disease. 

It's like genetics is too easily used as the scapegoat by individual dentists. But in conditions like Down Syndrome, it's probably pretty spot on.

Down Syndrome is known to cause pointy teeth, problems with the structure of teeth, while the hypotonia the Down Syndrome causes can affect the wrist action in cleaning teeth... As well Down Syndrome is known to cause extra teeth to grow, for a baby tooth or teeth to have to be pulled out to make room for an adult tooth that is growing in the wrong spot...

So yes, genetics is involved in the tooth disease process.

I have stimulated my children's brains from birth for the most part, and nearly all my five children have well formed teeth without any irregularity in their formation.

On the other hand, I did have teeth extracted as a child and I came down with adult teeth irregularity - jaw not big enough to hold my adult teeth, so I have one tooth that sticks out slightly and both my wisdom teeth are impacted under the surface. So I see a tooth disease process at work which begun with my baby teeth that affected the development of my adult teeth.

So in choosing a dentist to extract any teeth, you may want to clarify how the tooth extraction is going to affect the jaw and any other tooth development. You don't want malformed teeth or a malformed jaw as a result of a disease causing a tooth extraction, with the tooth extraction then in turn starting the process of teeth malformation via it's possible effect on the jaw.

Occupations that may damage your teeth or cost you a tooth or more:

Obviously any occupation or job that may cause physical trauma, such as boxing, are prety self evident.  The more interesting and relatively unknown ones are:

Professional swimmers and Swimming pool instructors risk teeth disease because of the high level of chemicals used in pools.

Wine tasters risk teeth disease because of the wine that is frequently swilled around the teeth.

People working in battery factories as the acid in the air causes teeth disease.

People employed in galvanising plants, as the galvanising process increases the amount of air borne corrosives, which causes tooth and teeth disease.

Preventing and Controlling Tooth and Teeth Disease:  2 More Points

The Importance of a dental hygienist visit once a year or as needed.

They'll give your teeth a professional clean for around $115.  Their cleaning removes the calcium deposits ( scale / calculus ) that are caused by the saliva in your mouth, which means they are allowing the decay causing bacteria beneath the scale to be removed also - thereby controlling / preventing tooth disease.

A dental hygienist will also thoroughly clean behind your teeth and in between the teeth, getting rid of all the scale - they use specialised cleaning instruments to break the calculus off, as well as specialised floss and polishing strips between the teeth.

Yearly Dental Check Ups / Visits

The dentist will also need to check your teeth yearly, more often in some cases.  They will look for dental disease and check if any preventative dental work is needed.  For example, when I visited the dentist today, everythings fine basically, except one of my fillings has chipped at the edges.  Replacing the filling will prevent tooth decay from getting a hold and further compromising the tooth structure.

Picture of braces courtesy of Xenia