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Dental Disorders & Disease

Keratocystic Odontogenic Tumor

I’ve gotten a few questions about odontogenic keratocysts lately, so I figured it would be good to write an article detailing what we know about them.

Before I get started, let me say that in 2005, the World Health Organization actually changed the name of odontogenic keratocyst to keratocystic odontogenic tumor.  It had been known as odontogenic keratocyst for nearly 50 years, since its discovery in 1956.  In honor of that tradition, and since most people still refer to it as an odontogenic keratocyst, I’m going to call it odontogenic keratocyst throughout this article.

For your viewing pleasure, here’s a photo of what an odontogenic keratocyst looks like at the cellular level — Thanks to Nephron for the photo.

Odontogenic Keratocyst

If you’re in the mood to see a picture of an odontogenic keratocyst after it has been cut out of someone’s jaw as well as the tooth, take a look at this case report and scroll down to the images.

What is an Odontogenic Keratocyst?

An odontogenic keratocyst is a benign tumor of the jaw (that’s why the new name, keratocystic odontogenic tumor makes sense.)   It is associated with an unerupted tooth about one-third of the time.

One of the reasons dentists recommend extracting wisdom teeth is that they can stay in the jaw and make it more likely that you’ll get problems such as an odontogenic keratocyst.

Odontogenic keratocysts grow inside your jaw bone, so you can’t see them.  They usually don’t cause your jaw to expand, they simply eat away at your bone.  They are able to move your teeth and even eat away at them.

What Causes an Odontogenic Keratocyst?

It’s not exactly known what causes an odontogenic keratocyst, but we know that it comes from the dental lamina.  The dental lamina is just a fancy name for the tissue that helps to form a developing tooth.  After the tooth is developed, this tissue is normally dissolved.  Sometimes the tissue sticks around and can give rise to an odontogenic keratocyst years later.

Where Do Odontogenic Keratocysts Occur?

They most often occur in the lower jaw in the area of the wisdom teeth. It has been reported that 60-80% of odontogenic keratocysts occur in the lower jaw. Approximately 1/3 of the time, odontogenic keratocysts are found in the upper jaw in the wisdom tooth area or the canine area.

Who Can Get an Odontogenic Keratocyst?

People of almost any age can get an odontogenic keratocyst.  Odontogenic keratocysts are more common in males than females. Some sources say that the peak age ranges from the teenage years to the early 20’s.  Another source says that 60% of all cases are diagnosed in people between the ages of 10-40.

How Common are Odontogenic Keratocysts?

I literally looked at about ten oral pathology textbooks in the library today trying to answer this question (posed by Stephen in this comment.)  The best I can do is to say that odontogenic keratocysts are rare and that they make up about 5 to 15% of all odontogenic cysts that are reported.

How is an Odontogenic Keratocyst Detected or Diagnosed?

An odontogenic keratocyst can be detected by routine dental x-rays.

Smaller odontogenic keratocysts usually don’t have any symptoms associated with them and are only discovered by taking routine x-rays. This is why it is important to have periodic x-rays taken at your dental checkup.

Find out how often you should get dental x-rays taken.

If an odontogenic keratocyst goes undetected and gets big it may burst, leaking keratin into the surrounding area in your jaw and causing lots of pain and swelling.

Treatment of an Odontogenic Keratocyst

Although there are promising new techniques to treat an odontogenic keratocyst, the most common method of treatment is simply going into the jawbone and removing the odontogenic keratocyst.

Recurrence of Odontogenic Keratocysts

It is estimated that about 30% of people with odontogenic keratocysts that have had them removed will get them again.  Most of them will recur within 5 years, but they can recur 10 or more years after they were oroginally removed.

Because of this is is extremely important to routinely follow-up with your dentist or oral surgeon so that they can take x-rays to ensure that it has not recurred.

It seems that odontogenic keratocysts come back for one of two reasons:

1 – The original odontogenic keratocyst wasn’t completely removed, and fragments that were left behind have started growing again to create a new odontogenic keratocyst.
2 – An entirely new odontogenic keratocyst has developed.

Neville & Damm’s oral pathology textbook states, “Odontogenic keratocysts often tend to recur after treatment.  Whether this is due to fragments of the original cyst that were not removed at the time of the operation tr to a “new” cyst that has developed from dental lamina rests in the general area of the original cyst cannot be determined with certainty.”

What Makes You More Likely to Get Recurrence of an Odontogenic Keratocyst?

So let’s say that you’ve had your odontogenic keratocyst removed and then it came back.  Is there a way to find out if it was the surgeon didn’t remove the whole cyst or whether a new one formed?

This thousand dollar (really) oral pathology text states, “When recurrences develop, those associated with the surgeon leaving residual cyst lining in bone become radiographically apparent within 18 months.”

If you don’t get a new odontogenic keratocyst within 18 months of having one removed, you can be fairly confident that it was fully removed by your surgeon, but there is still a possibility that you’ll get another one simply due to a new odontogenic keratocyst developing.

Another thing that affects the likelihood of recurrence is whether or not the cyst is removed in one whole piece.  If the cyst can be removed in one piece, with the lining of the cyst in tact, there is a much lower chance of recurrence.  On the other hand, if your surgeon has to remove the odontogenic keratocyst in several pieces, it is more likely to recur.


This article was on a more technical subject in dentistry.  My goal is to write so that people can easily understand even these complex topics.  If you have any questions, please let me know in the comments section below.

Also, if you have or have had an odontogenic keratocyst, feel free to share your experience in the comments as well so that others who are going through a similar situation can benefit.  Thanks for reading!

Congenitally Missing Teeth

Most people have thirty two permanent teeth that develop in their mouths.  Failure of any these teeth to fully develop is called congenitally missing teeth or, in scientific terms, hypodontia.

Congenitally missing teeth is actually one of the most common dental developmental abnormalities, even more common than double teeth and having an extra tooth.

In fact, about 20% of all adults are congenitally missing at least one tooth!

What Are the Most Common Congenitally Missing Teeth?

Congenitally Missing TeethThe most common permanent teeth to be congenitally missing are:

1 – Wisdom Teeth – The teeth all the way in the back of your mouth.  Wisdom teeth account for so many congenitally missing teeth that when you take them out of the equation, the percentage of adults with missing teeth drops from 20% to around 5%.
2 – Second Premolars – The teeth right in front of your molars.  If you only have one instead of two, you could either have a congenitally missing tooth or it’s possible that one of your premolars was taken out when you had braces.
3 – Upper Lateral Incisors – These are the two teeth to the side of your two front teeth.
4 – Lower Central Incisors – These are the two front teeth in the lower jaw. I’ve seen several adults in their 40’s who still have their lower front baby teeth because the permanent ones were congenitally missing!

Congenitally missing teeth are much more common in permanent teeth.  Only about 0.5 to 0.9% of kids have a congenitally missing baby tooth. If a child has a congenitally missing baby tooth, it is likely that there isn’t a permanent tooth developing under the gums of the congenitally missing tooth.

When people are missing a tooth, it is most common to only see one or two teeth missing rather than many teeth.  Neville and Damm’s oral pathology textbook states, “In whites with missing teeth, approximately 80% will demonstrate loss of only one or two teeth.”

Why Would a Tooth Be Congenitally Missing?

Forming a tooth is a complex process.  There are a lot of genetic signals that must be processed for everything to go correctly.  Most cases of hypodontia result from a lack of a little band of tissue, known as the dental lamina, underneath the gums to form.  Since the tooth forms from this band of tissue, the tooth will not form if the dental lamina does not form.

That band of tissue doesn’t form due to a variety of different genetic factors.  Scientists have pinpointed three main genes that play a big role in tooth development (AXIN2, PAX9, and MSX1.)  If there is a mutation on any one of these three genes, it could mean that a tooth will not form.

Congenitally missing teeth are often associated with various syndromes, one of which is Down’s syndrome.  Congenitally missing teeth can also be genetic.

Some dental experts believe that we are currently in the intermediate stage of an evolutionary change in the number of teeth that humans have and that future members of the human race will only have somewhere around 20 teeth instead of 32.

Treatments for Congenitally Missing Teeth

If you are congenitally missing your wisdom teeth, then no treatment is really necessary since most people have their wisdom teeth extracted.

Learn why dentists often recommend getting your wisdom teeth removed.

If you are missing your lateral incisors, your second premolars, or any other teeth, then there are a few treatment options.

Getting an implant to replace your missing tooth is probably the treatment of choice.  An implant has a root that integrates with your jaw bone and a crown to make it look like your natural tooth.

The next best option would be to get a bridge.  A bridge is like three crowns connected together.  The two teeth adjacent to the missing tooth are cut for dental crowns.  The bridge is then placed onto those two adjacent teeth.  The bridge has a fake tooth that connects to two crowned teeth and fills in the empty space from the congenitally missing tooth.

Another option for replacing a congenitally missing tooth would be to get a removable partial denture.  This is an appliance that you can put in and take out of your mouth.  It rests on your natural teeth and your gums and has teeth on it that replace the congenitally missing teeth.


Congenitally missing teeth is not as rare as you may have guessed.  The causes of this phenomenon vary and there are also multiple treatments available if you are missing one or more of your teeth.

Do you have any questions about congenitally missing teeth?  Did you have congenitally missing teeth?  If so, did you do anything to fill in the empty space?  I’d love to hear your questions, comments, and stories in the comments section below.

Thanks for reading!

Supernumerary Teeth
Extra Teeth: Supernumerary Premolars | ©

Has your child ever come up to you and told you that they have an extra tooth growing out of their upper jaw behind their permanent teeth?  It’s probably more likely that you’ve been told that your child has an extra tooth, or supernumerary tooth (we try to make up complicated words!) as dentists like to call it.

If so, you’re not alone!  It is estimated that supernumerary, or extra teeth occur in 2% of Caucasian children, with an even higher frequency in those of Asian descent.

Below you can see an x-ray of a child with a supernumerary tooth.  The original x-ray is on the left, and I outlined the supernumerary tooth in green in the x-ray on the right.

Extra Teeth: Supernumerary Mesiodens Tooth

This particular extra tooth is called a mesiodens.  That means that it is right between the two upper middle front teeth.  Only about 25% of these teeth actually erupt into the mouth.  Most mesiodens teeth stay in the jawbone and never make it into the mouth.

What Causes Supernumerary Teeth?

Currently, it is believed that supernumerary teeth occur due to the continued growth of the tissue that forms teeth, known as the dental lamina.

Supernumerary teeth can be hereditary or they may be associated with one of two conditions: Gardner’s Syndrome and Cleidocranial Dysplasia.  Supernumerary teeth can also occur in people that don’t have those two conditions and in those withouta family history of supernumerary teeth.

How Common Are Extra (Supernumerary) Teeth?

It is estimated that supernumerary teeth occur in 0.1-3.8% of Caucasians.  They are even more common than that in people of Asian descent, although I couldn’t find any hard numbers.

Supernumerary Teeth are twice as common in boys as they are in girls.  Most supernumerary teeth form before the age of 20, although they are more commonly found with the permanent teeth rather than the baby teeth.

What are Supernumerary Teeth Called?

Extra teeth have a lot of names!  They are classified based upon where they are located and what they look like.

If an extra tooth is located in the middle of the two front teeth, it is called a mesiodens. If the extra tooth is located around the molar area, it is called a paramolar. If the extra tooth is located behind the wisdom teeth, it is known as a distodens.

If an extra tooth is shaped like another “normal” tooth, it is called a supplemental tooth.  If it is not shaped like a normal tooth, then it is known as a rudimentary tooth.  Rudimental teeth are then classified based on what they look like:

  • Conical Rudimentary Teeth look small or peg-shaped.
  • Tuberculate Rudimentary Teeth appear to be barrel-shaped and have more than one cusp.
  • Molariform Rudimentary Teeth look similar to premolar or molar teeth, but not enough to be called a supplemental tooth.

What Does a Supernumerary Tooth Look Like?

Supernumerary Teeth: MesiodensWhen I was out visiting my sister last summer, she told me that my nephew had to get an extra tooth removed.  She told me I could even take a picture and put it up on Oral Answers.

You can see my nephew’s supernumerary tooth to the right.  It was a mesiodens, since it was growing right between his front two teeth.  As you can see, the tooth doesn’t really resemble any particular tooth, it just looks like a cylindrical piece of enamel.

Where Do Supernumerary Teeth Occur?

Almost all (around 95%) supernumerary teeth occur in the upper jaw.  They mostly occur between the upper two front teeth.  After that, you are most likely to find a supernumerary teeth behind the wisdom teeth.

Interstingly, supernumerary teeth don’t always occur in the jaws.  Neville’s Oral Pathology textbook states, “Although most supernumerary teeth occur in the jaws, examples have been reported in the gingiva, maxillary tuberosity, soft palate, maxillary sinus, sphenomaxillary fissure, nasal cavity, and between the orbit and the brain.  The eruption of accessory teeth is variable and dependent on the degree of space available.”

As you can see, supernumerary teeth can pretty much occur anywhere in your head, although they are most likely to occur in your jaws like the rest of your teeth.

Do You Need to Have Supernumerary Teeth Removed?

Most dentists recommend removing supernumerary teeth because they can cause problems.  Regezi’s Oral Pathology textbook states:

The significance of supernumerary teeth is that they occupy space. When they are impacted, they may block the eruption of other teeth, or they may cause delayed eruption or maleruption of adjacent teeth. If supernumerary teeth erupt, they may cause malalignment of the dentition and may be cosmetically objectionable.

Because they can cause problems, it is generally a good idea to have supernumerary teeth removed.


If you have extra teeth, don’t be alarmed!  It is pretty common to have supernumerary teeth.  You can work with your dentist to figure out what your options are for removing the tooth and aligning your smile correctly.

Have you had a supernumerary tooth?  Do you have any questions about supernumerary teeth?  I’d love to hear what you have to say in the comments section below.  Thanks for reading!

Oral Cancer and Whole Foods Plant Based Diet
©Elena Schweitzer/

37,000 people are diagnosed with oral or pharyngeal cancer every year.  That’s more than 100 people per day. Only an estimated half of those diagnosed with oral or pharyngeal cancer will be alive in five years.

Guess how many people die from oral cancer every single day.  24 (Source: American Cancer Foundation.)

Oral Cancer Prevention and a Plant Based DietGuess how many of those 24 people could have saved their lives by eating better and exercising.  8.

That’s nearly 3,000 people every year who could have lived longer had they only made a few simple dietary and lifestyle changes.

This article from the American Cancer Society’s Journal states, “Evidence suggests that one third of the more than 500,000 cancer deaths that occur in the United States each year can be attributed to diet and physical activity habits, with another third due to cigarette smoking. Although genetic inheritance influences the risk of cancer, and cancer arises from genetic mutations in cells, most of the variation in cancer risk across populations and among individuals is due to factors that are not inherited. Behavioral factors such as smoking cigarettes, consuming foods along certain patterns of diet, and staying active across the lifespan can substantially affect one’s risk of developing cancer.”

Dietary Recommendations for the Prevention of Oral Cancer

Last week I was doing an externship at a rural dental clinic.  During some down time, I picked up a copy of the February 2011 issue of the Journal of the American Dental Association.  The article Diet and Prevention of Oral Cancer really caught my eye.  My dad passed away from cancer when I was 17.  I’ve always been worried that someday I would end up with cancer too, so the prevention of cancer is something that interests me.

The authors concluded that swapping your regular American diet for a plant-based diet with more whole foods can go a long way in lowering your risk for oral cancer.  They state the following:

Evidence supports a recommendation of a diet rich in fresh fruits and vegetables as part of a whole-foods, plant-based diet, with limited consumption of meat, particularly processed meat. However, use of dietary supplements (including vitamins, minerals and other bioactive compounds) in the absence of deficiencies has not been shown to confer the same benefits as those of fruits and vegetables, and patients should not use them as a substitute for fruit and vegetable consumption.

The 2011 Cancer Prevention & Early Detection PDF Booklet from the American Cancer Society contains the following recommendations on page 17 that seem to echo the findings above.  The booklet includes these suggestions:

  • Consume a healthy diet, with an emphasis on plant sources.
  • Choose foods and beverages in amounts that help achieve and maintain a healthy weight.
  • Eat 5 or more servings of a variety of vegetables and fruits each day.
  • Choose whole grains in preference to processed (refined) grains.
  • Limit consumption of processed and red meats.
  • Limit consumption of alcoholic beverages, if you drink them. (Have no more than 1 drink per day for women and 2 per day for men.)

In 2002, researchers looked at many of the different studies relating diet and oral cancer.  They published their results in this paper.  Here’s an excerpt of their findings:

On the basis of the findings from the listed studies, there is enough evidence to point to a preventive role of vegetable intake, including green vegetables, cruciferous vegetables, and yellow vegetables, total fruit intake, and citrus fruit intake in oral, pharyngeal, and esophageal cancer development. Yellow fruits are likely to be protective. Carotene, vitamin C, and vitamin E are protective, most likely in combination with each other and other micronutrients. The role of vitamin A is not clear because of conflicting findings in the studies reviewed.

These three sources all seem to agree that foods from plant sources have a preventive effect on the development of oral cancer.  However, there are some foods that can increase your risk of developing oral cancer.

What Foods Increase the Risk of Oral Cancer?

Here’s another quote from the article Diet and Prevention of Oral Cancer that I referenced above:

Researchers have found that consumption of salted meat, processed meat and animal fat increases the risk of developing oral cancer. The results of a study conducted by Peters and colleagues showed that high consumption of dairy products is a risk factor for head and neck squamous cell cancers.

Based on the study above, the following foods increase your risk of developing oral cancer:

  • Salted Meat
  • Processed Meat
  • Animal Fat
  • Dairy Products at a High Consumption Rate


In essence, foods that originate from plant sources help decrease your risk of oral cancer, and foods from animal sources increase your risk for developing oral cancer.

If your diet looks similar to foods below, you’re probably doing a good job of lowering your risk for developing oral cancer.

Plant Based Diet and Oral Cancer

If oral cancer can be prevented so easily, isn’t it worth it to make some subtle changes to your diet?

Do you have any questions, comments, or concerns about how your diet can affect your risk of developing oral cancer?  I’d love to hear what you have to say in the comments section below.  Thanks for reading!

Tooth Pain and Sinus Infections

This past weekend, my wife told me that she was having the worst toothache of her life. When she came in for her checkup a few months ago, her teeth were in great shape.

Dental Sinus InfectionShe told me that the pain was constant and that it got worse when she stood up. I told her that I thought it was a sinus infection. She went to the doctor and found out that she did have a sinus infection.

Stories like my wife’s are fairly common — many people think that they have a problem with their teeth when they simply have sinusitis.

What Are Sinuses?

Each time you take a breath through your nose, air travels through your sinuses on its way down to your lungs.  Your sinuses are simply hollow, air-filled cavities in your upper jaw bone.  They are lined with a pink membrane that is similar to the pink lining on the inside of your mouth.

When the lining of your sinuses gets infected or inflamed, it is known as sinusitis.

Many people end up coming to the emergency room at our dental school with painful teeth.  Upon examination, we sometimes find that their teeth are healthy and that the real cause of their pain is a sinus infection or sinusitis.

How Your Sinuses Can Cause Tooth Pain

Below you’ll find a dental x-ray.  I outlined the floor of the maxillary sinus (the sinus located above your upper teeth) so that you can see how close it comes to the roots of your upper molars.

Maxillary Sinuses on a Dental X-Ray

On the left side, it looks like the sinus floor goes below the roots of the upper molars.  Usually this isn’t the case, and that illusion can be attributed to overlap as we are seeing a two dimensional image of a three dimensional object.  However, it does give you a pretty good idea of why sinus infections can make it seem like you have a toothache in your upper molars and premolars.

Want more details on how a tooth can cause a sinus infection? Then read this article: Can a Sinus Infection Be Caused by a Tooth?

How to Know If The Pain Is Coming From a Tooth or Your Sinuses

When a patient comes in with severe tooth pain, we normally take an x-ray of the offending tooth.  Tooth pain is usually caused by reversible and irreversible pulpitis.

We also do some tests on the tooth by feeling around it for an infection, tapping on it, and/or putting ice on it.  This allows us to better understand if the pain is coming from one tooth or not.

If the teeth don’t have any cavities in them and appear to be healthy, then we usually try to find another source of the pain, such as a sinus infection (sinusitis).

Symptoms of a Maxillary Sinus Infection

Although there are other sinuses, the main pair of sinuses that affect your upper teeth are the maxillary sinuses.  One of the main symptoms of maxillary sinusitis is continuous pain in your back upper teeth that changes (gets worse or better) when you move your head (such as lying down or standing up.)

Treatment of Maxillary Sinusitis

Maxillary sinusitis can be treated in a variety of ways.  Here are some common treatments for maxillary sinusitis:

  • Using a humidifier to moisten the air that you breathe in.  This helps to loosen any dried secretions that have accumulated in the sinuses.
  • Using nasal spray that contains phenylephrine or ephedrine.
  • Taking decongestants orally such as Sudafed (psedoephedrine)
  • Taking antibiotics if it is believed that the sinusitis is caused by bacteria.  Common antibiotics that are prescribed for sinusitis include amoxicillin, trimethoprimsulfamethoxazole, clavulanate with amoxicillin, azithromycin, and cefuroxime.


Although toothaches are generally caused by a problem with your tooth, it is important to understand that your teeth have neighbors, such as your sinuses, that can mimic a toothache.

Do you have any questions about sinusitis or sinus infections?  I’d love to hear what you have to say in the comments section below.  I’ll do my best to respond to your questions, comments, and/or concerns.  Thanks for reading!

Cause of Canker Sores

Ben, an Oral Answers reader, recently asked about what really causes canker sores (also known as aphthous ulcers.) He’s heard that sodium lauryl sulfate in toothpaste can cause canker sores, but not everyone who brushes their teeth gets canker sores.

Canker Sore
A canker sore on the posterior roof of the mouth

To be honest, there isn’t any one thing that can cause canker sores in everyone.  However, different things can cause canker sores in different people.

Here’s a list of 10 things that have been shown to cause canker sores in certain people.

10 Things that Cause Canker Sores In Susceptible People

1. Allergies

The book Oral and Maxillofacial Pathology by Neville says, “An antigenic stimulus appears to be the primary initiating factor in the immune-mediated cytotoxic destruction of the mucosa in many patients.”

Basically, it says that the main factor that causes the body to destroy it’s own oral tissues appears to be an allergic response.

There are a LOT of different allergens that have been associated with canker sores.  Here’s a list of the most common ones:

  • Sodium Lauryl Sulfate (SLS), commonly found as a main ingredient in toothpaste
  • Certain medications such as NSAIDS (ibuprofen), beta blockers, and nicorandil
  • A variety of foods, such as:
    • Citrus fruits
    • Strawberries
    • Tomatoes
    • Coffee
    • Gluten (the protein found in wheat products)
    • Dairy products, such as cow’s milk and cheese
    • Nuts
    • Chocolate
    • Food dyes
    • Food flavorings
    • Food preservatives

It’s important to remember that many of the foods listed above do not usually cause canker sores, but they have been found to be trigger foods in certain people. If you think that a certain food is causing your canker sores, you can try to pinpoint which food it is by using the above list and trying an elimination diet.  You will want to talk to your doctor about your concerns to get additional information before attempting to eliminate certain foods altogether.

2. Stress

Stress is a major cause of canker sores.  It is presumed that since stress weakens the body’s immune system that it makes it more susceptible to canker sores.

3. Trauma

Trauma has also been associated with canker sores.  Anytime the barrier over the deeper tissues inside your mouth is broken, there is a higher risk for canker sores in certain people.  The trauma can be caused by a variety of things, such as sharp foods like chips and crackers, biting, braces or hard=bristled toothbrushes.

4. Genetics

Your family history can play a big role in whether or not you get canker sores.  In fact, if both of your parents get canker sores, there’s a 90% chance that you will get them too!

Joseph A. Regezi, in his oral pathology book states, “Family history represents a risk factor. Over 40% of affected patients have a first-degree relative who is also affected by aphthous ulcers. There is a 90% degree of risk when both parents are affected.”

5. Compromised Immune System

Some people who have problems with their immune system have many canker sores.  For example, people with AIDS (Acquired Immunodeficiency Syndrome) frequently get aphthous ulcers.

6. Infectious Organisms

Certain organisms have also been implicated in causing canker sores in certain people.  Some examples of organisms that are associated with canker sores are:

  • Certain forms of streptococci
  • Helicobacter pylori
  • Herpes simplex virus
  • Varicella-Zoster virus (chicken pox)
  • Adenovirus
  • Cytomegalovirus

7. Nutritional Deficiencies

Nutritional deficiencies have been shown to be correlated with canker sores.  Shortages of the following vitamins and minerals are suspect:

  • Iron
  • Folic Acid
  • Zinc
  • The “B” Vitamins (Vitamin B1, B2, B6, and B12)

8. Stopping Smoking

When you smoke, the tissue lining the inside of your mouth gets slightly thicker.  Quitting smoking thins the lining inside of your mouth and makes you more susceptible to canker sores.

This doesn’t mean that you should smoke to avoid canker sores!  Smoking has many more serious negative effects on your oral health.  For example, smoking has been linked to oral cancer and smokers in general have less teeth than non-smokers.  So it is still a great idea to quit smoking if you currently do!

9. Hormones

Hormones can also affect whether or not you get canker sores.  The book Oral and Maxillofacial Pathology by Neville says, “In a small subset of female patients, a negative association was reported between the occurrence of [canker sores] and the luteal phase of the menstrual cycle—a period of mucosal proliferation and keratinization.”

The luteal phase of your menstrual cycle begins right after you ovulate (approximately day 14) and ends on the day you get your next period.  When the tissue inside your mouth gets thicker (i.e. – more keratin forms) then you see a decrease in the amount of canker sores.

10. Blood Abnormalities

Certain blood abnormalities, such as cyclic neutropenia have also been implicated in canker sores.  Regezi’s Oral Pathology textbook states the following (I bolded the part that deals with canker sores):

“Cyclic neutropenia, a rare blood dyscrasia, is manifested as severe cyclic depletions of neutrophils from the blood and marrow, with a mean cycle, or periodicity, of about 21 days…Fever, malaise, oral ulcers, cervical lymphadenopathy, and infections may appear during neutropenic episodes.”


There are a variety of things that can cause canker sores.  However, you may notice that nothing I mentioned above applies to you and you still have canker sores.  This is because we still don’t know everything that causes canker sores.  Researchers are still working to understand the exact reasons why some people get them and some people don’t.

Do you get canker sores?  Have you noticed that they are caused something that I didn’t mention above?  I’d love to hear your comments and questions in the comments section below.  Thanks for reading!

Causes of Dry Mouth Xerotomia
©Carlos Castilla/

Dry mouth, or xerostomia to medical professionals, occurs in 25% of older adults and has even been reported to occur in 10% of adults in their 30’s.  Dry mouth is a condition that can have a negative impact on your oral health.  It also impacts your ability to eat food and speak, and has been said to cause bad breath.

Basically, if you have dry mouth you are missing out on many of the benefits that your spit provides to your mouth.

I’ll talk about all of the effects of dry mouth in a future article.  What I want to talk about right now is what causes dry mouth.  Dry mouth is caused by a variety of different factors.  I’ve listed six main causes of dry mouth, which you can find below.

Six Causes of Dry Mouth, Xerostomia

Dry Mouth Causes

1 – Medications – This is one of the most common causes of dry mouth.  There are literally hundreds of medications that cause dry mouth.  Some of the more common ones are anti-depressants, sedatives, beta-blockers, high blood pressure medication, antihistamines, and cold/flu medications.  Other drugs, such as tobacco and alcohol, can directly dry out the mouth.

Learn more about 348 medications that cause dry mouth.

2 – Anxiety, Depression, or Stress – These conditions have been shown to cause dry mouth.  The best way to treat it is to find effective ways to manage your anxiety, depression, or stress.

3 – Diabetes – There is some debate whether diabetes causes dry mouth or not.  Here’s what the book Oral and Maxillofacial Pathology by Neville has to say about diabetes and dry mouth:

Xerostomia, a subjective feeling of dryness of the oral mucosa, has been reported as a complaint in one third of diabetic patients.  Unfortunately, studies that attempt to confirm an actual decrease in salivary flow rate in diabetic patients have produced conflicting results.  Some studies show a decrease in salivary flow; some, no difference from normal; and some, an increased salivary flow rate.

4 – Autoimmune Diseases such as Sjögren’s syndrome, HIV, and Graft-versus-Host disease.  Sjögren’s syndrome causes dry mouth and dry eyes.  In other immunologic diseases, it is suspected that the body’s immune system is attacking the salivary glands, thus decreasing the amount of saliva that is produced.

5 – Radiation treatment to the head and/or neck area – Radiation treatment to the head and neck area can cause damage to the salivary glands.  Some of the glands can recover and produce saliva normally after radiation treatment.  The biggest salivary gland, however, usually has trouble recovering and can be permanently damaged, leading to chronic dry mouth.

6 – Hormone changes – Hormonal changes occur with pregnancy and menopause in females.  These hormonal changes have been associated with dry mouth.  If you are pregnant and experiencing dry mouth, your dry mouth should resolve once your baby is born.  If you have dry mouth associated with menopause, you may want to see your dentist to see what kind of treatment is available.


As you can see, there are numerous causes for dry mouth.  Do you have dry mouth?  Please leave any comments or questions in the comments section below.

Sources: Xerostomia: Etiology, Recognition, and Treatment | ADA: Do you Have Dry Mouth? | Oral & Maxillofacial Pathology by Neville

Tetracycline Teeth Staining Cause and Treatments
©Gordana Sermek/

When I was a little boy, I remember seeing my brother in the bathroom trying to bleach his teeth.  He tried many different formulations of bleaching agents to try to remove the staining on his teeth.

Tetracycline Teeth StainingI asked him about it recently, and he told me he wasn’t sure how it happened.  We suspected that my mom unknowingly took some sort of antibiotic that stained his teeth when she was pregnant with him or that he had taken something as a kid.  He couldn’t remember.

Tetracycline Teeth Staining Close-Up ViewThen, I called my mom.  She said that she didn’t take anything during her pregnancy and the discoloration came from a drug that was prescribed to him at a young age.  Whatever the reason, nobody likes to have discolored teeth.

To the right is a close-up view of the same patient in the photo above.  As you can see, the tetracycline has changed the color of his teeth.

Tetracycline Tooth Staining

Tetracycline can stain the teeth anywhere from a bright yellow shade to dark brown.  Usually the staining starts out as a yellow color.  Over time, as the tooth is exposed to light, a chemical reaction occurs and the yellow turns to a dark brown color.  For this reason, many people with tetracycline tooth staining have brown teeth in front (the teeth that are exposed to the most light) and yellow teeth in the back (where not as much light reaches.)  Under ultraviolet light, tetracycline staining can appear bright yellow.

However, it’s not just tetracycline that stains the teeth – there are many other drugs as well.

Other Drugs That Cause Staining of Teeth

Many of tetracycline’s homologues (similar drugs) are all associated with discoloration.  Chlortetracycline, demethylchlortetracycline and oxytetracycline can all cause brown/gray/yellow staining of the teeth.

Ciprofloxacin is an antibiotic that can be given intravenously to infants for treatment of a Klebsiella infection.  It can stain the teeth a green color, but the staining is usually more mild than tetracycline staining.

Minocycline hydrochloride is an antibiotic used to treat acne and rheumatoid arthritis.  It is believed that minocycline binds to the tooth and then oxidizes it, producing a discoloration.  Minocycline is able to stain teeth even after they are fully developed, unlike the tetracycline family of antibiotics and ciprofloxacin.


Tetracycline can cross the placental barrier and incorporate into the developing tooth.  It should be avoided (if possible) by mothers who are pregnant and also in kids until they are at least seven or eight years of age.

The book Oral Pathology: Clinical Pathologic Correlations by Regezi says the following about how tetracycline staining is caused:

Because tetracycline can cross the placenta, it may stain primary teeth if taken during pregnancy. If it is administered between birth and age 6 or 7 years, permanent teeth may be affected. Only a small minority of children given tetracycline for various bacterial diseases, however, exhibit clinical evidence of discoloration. Staining is directly proportional to the age at which the drug is administered and the dose and duration of drug usage.

Since there are many other antibiotics available that are as effective as tetracycline without the discolored teeth as a side-effect, tetracycline is usually not prescribed to children except in rare circumstances.  Your doctor will be able to explain the reasoning if your child is ever prescribed tetracycline.

Treatment of Tetracycline Stained Teeth

It is very difficult to treat internal staining of teeth because it affects the dentin layer underneath the enamel.

For an overview of the layers of the teeth, check out this article on the anatomy of a tooth.

There are a variety of ways to treat tetracycline stained teeth depending on the severity of the staining.  The most conservative is bleaching the tooth.  If the tooth has undergone root canal treatment, it may be more effective to use an internal bleaching technique where the dentist puts a bleach inside the tooth to bleach it from the inside out.  Internal bleaching is not possible with teeth that have not undergone root canal treatment because there is still living pulp inside the tooth where the bleach would be put.

If bleaching doesn’t work, there are more invasive treatments.  The dentist can shave off the outer layer of the tooth and put an aesthetically-pleasing tooth-colored filling on the front-facing surface of the tooth.

Another treatment option is putting veneers (a thin layer of tooth-colored porcelain) over the teeth.

The most drastic treatment would be to cut around the whole tooth and put an aesthetic crown over the tooth.  This may end up being the most aesthetic option for severe tetracycline-stained teeth, but it is also the most expensive.  I believe my dental school would charge somewhere around $500 for this procedure, which means it is probably near $1,000 if you get it done in private practice.


I hope this article helped you to better understand why antibiotics stain the teeth and what you can do to prevent it.

Are your teeth stained due to a medication such as tetracycline?  Have you done anything about it?  Don’t hesitate to share your experience in the comments so others who have the same problem can see what worked for you.

If you have any questions or comments, go ahead and leave those in the comments section below as well.  Thanks for reading!

I want to thank Dr. James R. Donley, DDS for kindly allowing me to use his photos (the bottom two photos) in this article.