The 10 Most Common Oral Diseases

The oral cavity and teeth are indicative of people's health status. Meet with us 10 common oral diseases that take thousands of people to the dentist each year.

Written and verified by el biólogo Samuel Antonio Sánchez Amador.

Last update: 07 July, 2023

The oral cavity is a fascinating microecosystem from a biological point of view. Along with the upper respiratory tract, it’s the area of the body most exposed to foreign substances (food, drinks and other elements), and a large number of microorganisms and living beings inhabit it. Unfortunately, there are certain common oral diseases that threaten this balance.

Oral pathologies can take place in the teeth (dental diseases), in the mouth (diseases of the oral cavity) or in both sections at the same time. Depending on whether the affected tissue is soft or hard, the symptoms can be very different, and even worsen to endanger the life of the patient. If you want to know more about this group of conditions, keep reading.

What are the most common oral diseases?

Before exploring 10 diseases that are usually experienced in the teeth and in the oral cavity, we find it interesting to frame the epidemiological situation of this group of pathologies. The World Health Organization (WHO) provides us with a series of data that we summarize in the following list:

• Untreated oral diseases have a very high burden of disease. They can lead to chronic pain, acute discomfort, disfigurement, and even death if left unaddressed.
• It is estimated that the prevalence of these conditions is 3.5 billion affected people worldwide, that is, almost half of the population.
• Untreated decay in permanent teeth is the most common oral condition. On the other hand, more than 530 million children suffer from untreated cavities in their baby teeth, mainly due to a lack of access to adequate medical systems.
• Oral cancer is one of the 3 types of cancer with the highest incidence in Asian regions. Each year, more than 575,000 new cases are diagnosed globally. 90% of the cases are detected in people over 40 years of age.

All these data show us that oral diseases are very common around the world. Here we take a comprehensive look at the 10 most common oral diseases in the world and their possible triggers. Don’t miss it.

1. Caries

As reported by the Infomed portal, cavities affect 80% of the world’s population at some point in their life. After reading this number, it is impossible to disprove that they represent the most common dental disease in the world. We can go further, because, even though 60 to 90% of children have cavities, this figure is close to 100% in adults.

Tooth decay is a chronic non-communicable disease mediated by oral bacteria. They are the leading cause of oral pain and tooth loss worldwide, but, ironically, they can be prevented with proper diet and consistent oral hygiene. The main triggers of this pathology are the following:

1. Cariogenic bacteria: These are the microorganisms that initiate the formation of cavities. They have aciduric properties, that is, they demineralize the enamel and dentin of the teeth and create cavities.
2. Fermentable carbohydrates: The sugars in fruits, sweets, industrial pastries, soft drinks and many more products favor the presence of cavities. These compounds feed “bad” bacteria, which accelerates tooth damage.
3. Susceptible teeth: Some people have more fragile teeth than others in terms of their layers and mineral composition. This predisposes to tooth decay.
4. Time: The more time passes in the life of the individual, the more the teeth and mouth wear out by simple use.

Tooth decay happens due to the demineralizing action of bacteria and can be coronal or root. Tooth pain, halitosis, and dental phlegmons are the most common symptoms of this condition. Treatment depends on the severity of the condition, but antibiotics are usually prescribed to kill the infection and replacements of the affected teeth.

2. Oral cancer

As studies indicate, 3% of all cancers are located in the oral cavity. In Asia, this type of malignancy represents 40% of all malignancies, while in regions such as the US the prevalence is much lower, with about 54,000 new cases diagnosed each year. 90% of them are oral squamous cell carcinomas.

Survival reported in this type of neoplasia is variable, but ranges between 40-56% after 5 years. Lip cancer reports 70% of surviving patients, while cancer in other areas of the mouth is much worse, with a survival rate of 30%.

The etiology of oral cancer is unknown, but predisposing agents are known to exist. Eight out of 10 patients are smokers, whether of cigarettes, cigars, chewing tobacco, shishas (or hookahs) and other methods. The most common symptoms are loose teeth, a sore that won’t heal, and a soft growth or bump inside the mouth.

3. Gingivitis

Gingivitis is another of the most common oral diseases. As indicated by medical studies, this condition can occur in up to 50% of people over 19 years of age, a value that decreases as age increases. Interestingly, the prevalence in people over 65 is 36%.

Gingivitis is a common, mild form of gum disease that causes irritation, swelling, and inflammation of the part of the gums that surround the base of the teeth. The most common cause is poor oral hygiene and it follows the following steps:

1. Plaque forms on teeth: The term “dental plaque” refers to a sticky film that forms when food, liquids and bacteria combine in the dental area. This plaque requires daily elimination, as it forms every day when we eat.
2. Plaque turns into tartar: If a person doesn’t brush their teeth regularly, this plaque turns into tartar, now hardened by the deposit of minerals. Tartar protects bacteria and encourages their growth, which causes irritation at the gum line.
3. Inflammation of the gum: The longer the tartar deposited on the teeth passes, the more bacteria will grow and the oral environment will be irritated. In the end, gingivitis will develop.

4. Periodontitis

Periodontitis is a continuation of the previous clinical picture. When gingivitis is not treated, the soft tissue of the gums is damaged by bacteria and immune inflammation and, without medical attention, the bone that supports the teeth is destroyed. The symptoms are much more serious, and among them the following stand out:

• Swollen, swollen, bright red, and even purple gums
• Mouth bleeding that appears easily, especially when the patient brushes his teeth
• Bad breath
• Pus between the teeth and gums, and even loss of teeth due to the destruction of the bone that holds them
• Pain when chewing
• Changes in the way teeth meet when biting

When the bacterial infection gets out of control, antibiotics are often necessary. Scraping, root planing and, in some cases, bone or soft tissue grafts may also be required. Periodontitis is a very serious condition that can quickly become complicated if medical attention is not sought.

5. Hand, foot and mouth disease

Hand-foot-and-mouth disease is a typical mild viral condition in young children caused by the pathogens coxsackie virus and enterovirus. The incidence is about 203 cases per 100,000 inhabitants in American regions, which makes this disease a fairly common infection.

Symptoms begin 3 to 6 days after exposure to the virus, which is usually transmitted through nasal secretions, saliva, and droplets emitted by an infected patient when they cough or sneeze. Some of the most relevant clinical signs are the following:

• Low fever, with a maximum of 39°C
• Loss of appetite and pain in the mouth
• Painful lesions with redness on the tongue, gums, and inner cheeks
• General irritability

Although this condition is not exclusive to the oral cavity, it does show very clear symptoms in this area, which is why it can be considered one of the most common oral diseases in the world. There is no specific treatment, as the immune system effectively fights the virus and clinical signs resolve on their own within a week almost always.

6. Dental trauma

Dental trauma is very common, especially in childhood. The prevalence varies between 10 and 47% of infants, and some authors even place these lesions in 50% of the pediatric population, with 2 incidence peaks: between 2 and 3 years and between 8 and 10 years. In addition, they are more frequent in the male gender.

It is common for the etiology of these events to be multifactorial, with risk-taking, inattention and hyperactivity standing out above the rest. Environmental factors are also determining factors, since the child’s home and the places where they play can make it more likely for them to suffer tooth damage.

Some of the most common risk factors for dental trauma include the following:

• Practicing contact sports and extreme sports
• Having dental malocclusion, which is the incorrect alignment of the teeth of the lower and upper jaw
• Having had orthodontic treatment at the time of injury
• Having previous pathologies: epilepsy, stroke, heart attacks and other conditions that could cause a loss of consciousness and falls
• Consuming alcohol, drugs and other substances that promote loss of coordination

In general, these types of injuries are solved with the insertion of a dental crown, which allows the tooth to recover its shape and physical appearance. If there’s nerve damage, a root canal and complete replacement of the injured tooth is required.

7. Oral candidiasis

In oral yeast infections, the fungus Candida albicans accumulates in the lining of the mouth. This is an opportunistic diploid microorganism, as it is part of the normal human microbiota and doesn’t cause problems unless the immune system is weakened.

Unfortunately, oral yeast infection is one of the most common symptoms in HIV-positive people who progress to the stage of AIDS. Because the lymphocyte count is extremely low in patients in this phase, the fungus proliferates in the oral cavity, generating a visible whitish film. It is estimated that 30 to 90% of AIDS cases manifest with this infection.

8. Canker sores

As indicated by the United States National Library of Medicine, a canker sore is an open sore or ulcer inside the mouth. Some of the triggers for these injuries are as follows:

• A viral infection, but not to be confused with cold sores.
• An oral injury after a dental repair carried out by a professional
• A bite on the cheek or tongue while eating something
• Emotional stress and hormonal changes
• Vitamin deficiencies in the diet
• Certain food allergies

Apart from these risk factors, in many cases canker sores don’t have a clear origin. It should be noted that they represent one of the most common oral diseases, since a prevalence of 5 to 80% of the population is estimated at any given time and place. They appear with great frequency in children and adolescents, being especially common between 10 and 19 years.

9. Cold sores

Cold sores are a condition caused by the herpes simplex virus. It is an extremely common oral infection, since cited sources estimate that up to 67% of people have been infected at some point with herpes simplex type 1. The most striking symptom of this condition is the presence of blisters on the edge of lips and a notable itch.

The most curious thing about this viral agent is that it remains latent in the nerve ganglia throughout a person’s life, and is able to reactivate and cause symptoms periodically. Recurrence is marked by other infections, stress, fatigue, changes in the immune system, and skin lesions.

10. Halitosis

Halitosis is more of a clinical sign than a disease alone, but it deserves a special place among common oral diseases, as it is estimated that up to 50% of people have bad breath at some point in their life. Halitosis is normal when waking up in the morning, but it can indicate a pathology if it occurs throughout the day.

The causes are multifactorial: poor oral hygiene, chronic gastritis, oral infections and even lung cancers. Although many triggers can be detected, 90% of halitosis cases find their cause in the teeth or gums (oral cavity).

Common oral diseases: a heterogeneous group of pathologies

As you have seen, the 10 most common oral diseases have very different etiologies, from cell mutations and tumors (cancer) to bacterial invasion of the gums (gingivitis and periodontitis). In any case, almost all of them can be avoided with the following habits: not smoking, brushing your teeth 2-3 times a day and eating healthily.

Ultimately, it should be noted that a mouth infection can become serious if it isn’t treated in time. If bacteria enter the bloodstream, there’s a risk of fatal bacteremia and septicemia. With these pathologies, a visit to a medical professional is an urgent matter.