Periodontal Disease – Risk Factors

Risk Factors

More than 75% of American adults have some form of gum disease, but according to a major survey, only 60% have any significant knowledge about the problem. Gum inflammation and ulcers are common and not all people with these problems develop periodontal disease. Still, about 30% of people are genetically susceptible to periodontal disease. Other factors also put individuals at higher risk.

Oral Environment

Lack of Oral Hygiene. Lack of oral hygiene encourages bacterial buildup and plaque formation.

Sugar and Acid. The bacteria that cause periodontal disease thrive in acidic environments. Therefore, eating sugars and other foods that increase the acidity in the mouth increase bacterial counts.

Poorly Contoured Restorations. Poorly contoured restorations (fillings or crowns) that provide traps for debris and plaque can also contribute to its formation.

Anatomical Tooth Abnormalities. Abnormal tooth structure can increase the risk.

Wisdom teeth. Wisdom teeth, also called third molars, can be a major breeding ground for the bacteria that cause periodontal disease. In fact, for patients in their 20s, periodontal disease is most likely to occur around the wisdom teeth. Research suggests that periodontitis can occur in wisdom teeth that have broken through the gum as well as teeth that are impacted (buried). Periodontal disease can also be present even in patients with wisdom teeth who do not have any symptoms. Experts recommend that adolescents and young adults with wisdom teeth should have a dentist check for signs of periodontal disease


Children and Adolescents. Gingivitis, in varying degrees, is nearly a universal finding in children and adolescents. In rare genetic cases, children and adolescents are subject to destructive forms of the disease. Researchers have also observed some of the organisms seen in periodontal disease in young children without signs of gum problems. Healthy children, however, do not generally harbor two primary periodontal bacteria, P. gingivalis and T. denticola. The disease is also uncommon in teenagers.

Adults. One survey reported that 3.6% of adults between the ages of 18 – 34 had periodontal disease. As people age, the risk for periodontal disease increases. Over half of American adults have gingivitis surrounding 3 – 4 teeth and 30% have significant periodontal disease surrounding 3 – 4 teeth. In a study of people over 70 years old, 86% had at least moderate periodontitis and over a quarter of them had lost their teeth.

Female Hormones

About three-quarters of periodontal office visits are made by women, even though women tend to take better care of their teeth than men. Female hormones affect the gums, and women are particularly susceptible to periodontal problems. Hormone-influenced gingivitis appears in some adolescents, in some pregnant women, and is occasionally a side effect of birth control medication.

Before Menstruation. Gingivitis may flare up in some women a few days before they menstruate when progesterone levels are high. Gum inflammation may also occur during ovulation. Progesterone dilates blood vessels causing inflammation, and blocks the repair of collagen, the structural protein that supports the gums.

Pregnancy. Hormonal changes during pregnancy can aggravate existing gingivitis, which typically worsens around the second month and reaches a peak in the eighth month. Pregnancy does not cause gum disease, and simple preventive oral hygiene can help maintain healthy gums. Any pregnancy-related gingivitis usually resolves within a few months of delivery. Because periodontal disease can increase the risk for low-weight infants and cause other complications, it is important for pregnant women to see a dentist.

Oral Contraceptives. Some studies report that oral contraceptives containing the synthetic progesterone desogestrel (but not dienogest, another common progesterone) increase the risk for periodontal disease.

Menopause. Estrogen deficiency after menopause reduces bone mineral density, which can lead to bone loss. Bone loss is associated both with periodontal disease and osteoporosis. A 2005 study found that bone loss in the alveolar bone (which holds the tooth in place) was a major predictor of tooth loss in postmenopausal women. Periodontal disease is the main cause of alveolar bone loss. During menopause, some women may also develop a rare condition called menopausal gingivostomatitis, in which the gums are dry, shiny, and bleed easily. Women may also experience abnormal tastes and sensations (such as salty, spicy, acidic, burning) in the mouth.

Family Factors

Periodontal disease often occurs in members of the same family. Genetics, intimacy, hygiene, or a mixture of factors may be responsible. Studies have found that children of parents with periodontitis are 12 times more likely to have the bacteria thought to be responsible for causing plaque and, eventually, periodontal disease.

Genetic Factors. According to a 2000 study, genetic factors may play the critical role in half the cases of periodontal disease. Up to 30% of the population may have some genetic susceptibility to periodontal disease. For example, some people with severe periodontal disease have genetic factors that affect the immune factor interleukin-1 (IL-1), a cytokine involved in the inflammatory response. Such individuals are up to 20 times more likely to develop advanced periodontitis than those without these genetic factors. Early onset and rapidly progressive periodontal disease also have strong genetic components.

Intimacy. Intimate partners and spouses of people with periodontal disease may also be at risk. Researchers have found that the bacteria P. gingivalis may be contagious after exposure to an infected person over a long period of time. There is no risk from short exposure such as after a fast kiss or when sharing an eating utensil.

Smoking and Nicotine

Smoking is the single major preventable risk factor for periodontal disease. The habit can cause bone loss and gum recession even in the absence of periodontal disease. A number of studies indicate that smoking and nicotine increase inflammation by reducing oxygen in gum tissue and triggering an over-production of immune factors called cytokines (specifically ones called interleukins), which in excess are harmful to cells and tissue.

Furthermore, when nicotine combines with oral bacteria, such as P. gingivalis, the effect produces even greater levels of cytokines and eventually leads to periodontal connective tissue breakdown. Studies suggest that smokers are 11 times more likely than nonsmokers to harbor the bacteria that cause periodontal disease and four times more likely to have advanced periodontal disease. In one study more than 40% of smokers lost their teeth by the end of their lives.

The risk of periodontal disease increases with the number of cigarettes smoked per day. Smoking cigars and pipes carries the same risks as smoking cigarettes. Exposure to secondhand smoke is also associated with a 50 – 60% increased risk for developing periodontal disease, according to a 2001 study. Fortunately, when smokers quit, their periodontal health gradually recovers to a state comparable to that of nonsmokers.

Diseases Associated with Periodontal Disease

Diabetes. Much evidence exists on the link between type 1 and 2 diabetes and periodontal disease. Diabetes causes abnormalities in blood vessels, and high levels of specific inflammatory chemicals such as interleukins, that significantly increase the chances of periodontal disease. High levels of triglycerides (which are common in type 2 diabetes) also appear to impair periodontal health. A high blood sugar level, which is the hallmark of diabetes, has even been associated with severe periodontal disease in people without diabetes, according to a 2000 study. Obesity, which is common in type 2 diabetes, may also predispose a person to gum disease. Controlling both type 1 and 2 diabetes may help reduce periodontal problems. For children with diabetes, good oral hygiene should begin at a young age. A 2006 study suggested that gum problems can start as early as 6 years of age in children with diabetes.

Osteoporosis. Osteoporosis (loss of bone density) has been associated with periodontal disease in postmenopausal women. There have also been a few reports of osteonecrosis (bone decay) of the jaw in patients who take oral bisphosphonate drugs such as alendronate (Fosamax). Osteonecrosis of the jaw is a rare, but serious, condition. As a precaution, the American Dental Association (ADA) recommends that patients who are prescribed bisphosphonate drugs get a thorough dental exam before beginning drug therapy, or as soon as possible after beginning therapy. The ADA also recommends that patients who take oral bisphosphonate drugs should discuss with their dentists any potential risks from dental procedures (such as extractions and implants) that involve the jawbone. In any case, be sure to inform your dentist if you are taking a bisphosphonate drug.


Osteoporosis is a condition marked by progressive loss of bone density, thinning of bone tissue, and increased risk of fractures. Osteoporosis may result from disease, dietary or hormonal deficiency, or advanced age. Regular exercise and vitamin and mineral supplements can reduce and may even reverse loss of bone density.

Cancer. Patients who are treated for bone cancer, or cancers that have spread to the bone, sometimes receive intravenous bisphosphonate drugs to help strengthen bone. These drugs can increase the risk of developing osteonecrosis (bone decay) of the jaw. Symptoms of osteonecrosis of the jaw include loose teeth, exposed jawbone, pain or swelling in the jaw, gum infections, and poor healing of the gums. About 1 – 10% of patients treated with intravenous bisphosphonates develop this condition. Patients who take oral bisphosphonate drugs also have a slight risk, but 94% of osteonecrosis of the jaw cases involve patients who received bisphosphonates intravenously. If possible, see a dentist for a complete oral exam before beginning bisphosphonate therapy. In any case, be sure to inform your dentist if you are receiving intravenous bisphosphonates. Your dentist or oral surgeon may need to take special precautions when performing dental surgery.

Herpes-Related Gingivitis. Herpes virus is a common cause of gingivitis in children and has become increasingly common in adults. It typically starts out with a purplish color and “boggy” sensation in the gums. Multiple blisters may form across the mucus membranes in the mouth and gums, followed by ulcers. They usually resolve in 7 – 14 days.

HIV-Associated Gingivitis. HIV-associated gingivitis has been reported in 15 – 50% of patients with HIV or AIDS. HIV-positive individuals harbor larger numbers of periodontal bacteria (candida albicans, P. gingivalis, black-pigmented anaerobic rods, and A. actinomycetemcomitans) than people without HIV. Severe pain is characteristic, along with odor, spontaneous bleeding, ulcers, and swollen, bright red gums. The inflammation never recedes, but halitosis and acute episodes can be managed by conventional cleaning treatments. Its severest form, known as necrotizing stomatitis, can be diagnostic for AIDS. In addition to bleeding, the gums in the front of the mouth are a yellowish-gray color, and bone thrusts out.

Autoimmune Diseases. Autoimmune conditions (Crohn’s disease, multiple sclerosis, rheumatoid arthritis, lupus erythematosus, CREST syndrome) have been associated with a higher incidence of periodontal disease. Some research suggests that periodontal disease may even play some causal role. For example, one 2002 study suggested that P. gingivalis, one of the major bacteria in periodontal disease, was associated with destructive processes in the brain leading to multiple sclerosis. Still, more research is needed to determine a definitive association between these diseases.

Other Diseases. People with tuberculosis, syphilis, Wegener’s granulomatosis, amyloidosis, and many genetic disorders are also at higher risk for periodontitis.

Vitamin C Deficiencies

Vitamin C helps the body repair and maintain connective tissue, and its antioxidant effects are important in the presence of tissue-destroying oxidants in periodontal disease. A large 2000 study found that people who consumed less than the recommended daily allowance of vitamin C, 60 mg (about one orange) were 1.5 times more likely to develop severe gingivitis than those who consumed more than 180 mg each day. (It should be noted that smoking also depletes vitamin C supplies.)

Ethnic, Socioeconomic, and Geographic Factors

Dental disease is most likely to affect the poor. Children and the elderly suffer the worst oral care, and ethnic minorities follow. A 2002 study reported that the amount of oral bacteria was greater in people who visited their dentist the least and when educational levels were low. Ethnicity played no role. It is distressing enough that 44 million Americans lack medical insurance, but almost 2.5 times that number lack dental insurance. In a survey of residents of five states (Arizona, California, Hawaii, Oregon, and Wisconsin), the rate of total tooth loss was less than 20%. In three states (Kentucky, Louisiana, and West Virginia) it was greater than 40%.

Drug-Induced Gingivitis

Gingival overgrowth can be a side effect of nearly 20 different drugs, most commonly phenytoin (Dilantin), cyclosporine (Sandimmune), and a short-acting form of the calcium channel blocker nifedipine (Procardia).

Other Causes of Gum Inflammation

Several other conditions can also cause gum inflammation, and some have been associated with periodontal disease. They include:

  • Mouth breathing
  • Psychologic stress. Stress can affect the immune system. Some studies suggest that stress can influence the development of chronic inflammatory diseases, like periodontitis.
  • Alcohol abuse. One study reported a higher incidence of periodontal disease, tooth decay, and possibly precancerous areas in patients who abuse alcohol.
  • Canker sores (aphthous ulcers)
Canker sore (aphthous ulcer)                     Click the icon to see an image of a canker sore.
  • Self-injury in psychologically disturbed patients
  • Hereditary gingival fibromatosis. A rare genetic disease associated with both gum overgrowth and hairiness. It is often associated with gingivitis and periodontal disease.
  • Desquamative gingivitis. With this condition the outer layer of the gum tissue desquamates (peels away), exposing an acutely red surface. It usually occurs as a result of an allergic reaction or of skin diseases such as lichen planus, benign mucous membrane pemphigoid, bullous pemphigoid, and pemphigus vulgaris. (Bacteria may also play a role in this gum disease.) This condition generally resolves when the underlying problem is treated. It is fairly common in middle-aged women.

Review Date: 11/10/2006
Reviewed By: Harvey Simon, MD, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (


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