Periodontal disease
Periodontal disease, also known as gum disease, is a set of inflammatory conditions affecting the tissues surrounding the teeth.[5] In its early stage, called gingivitis, the gums become swollen and red and may bleed.[5] It is considered the main cause of tooth loss for adults worldwide.[7][8] In its more serious form, called periodontitis, the gums can pull away from the tooth, bone can be lost, and the teeth may loosen or fall out.[5] Halitosis (bad breath) may also occur.[1]
Periodontal disease
Gum disease, pyorrhea, periodontitis
- Periodontitis /ˌpɛrioʊdɒnˈtaɪtɪs/, pyorrhea /ˌpaɪəˈriːə/
Red, swollen, painful, bleeding gums, loose teeth, bad breath[1]
Getting gingivitis[3]
Dental examination, X-rays[1]
Good oral hygiene, regular professional cleaning[5]
538 million (2015)[6]
Periodontal disease is generally due to bacteria in the mouth infecting the tissue around the teeth.[5] Factors that increase the risk of disease include smoking,[4] diabetes, HIV/AIDS, family history, high levels of homocysteine in the blood and certain medications.[1] Diagnosis is by inspecting the gum tissue around the teeth both visually and with a probe and X-rays looking for bone loss around the teeth.[1][9]
Treatment involves good oral hygiene and regular professional teeth cleaning.[5] Recommended oral hygiene include daily brushing and flossing.[5] In certain cases antibiotics or dental surgery may be recommended.[10] Clinical investigations demonstrate that quitting smoking and making dietary changes enhance periodontal health.[11][12] Globally, 538 million people were estimated to be affected in 2015 and has been known to affect 10–15% of the population generally.[7][8][6] In the United States, nearly half of those over the age of 30 are affected to some degree and about 70% of those over 65 have the condition.[5] Males are affected more often than females.[5]
Periodontitis is an inflammation of the periodontium, i.e., the tissues that support the teeth. The periodontium consists of four tissues:
The primary cause of gingivitis is poor or ineffective oral hygiene,[45] which leads to the accumulation of a mycotic[46][47][48][49] and bacterial matrix at the gum line, called dental plaque. Other contributors are poor nutrition and underlying medical issues such as diabetes.[50] Diabetics must be meticulous with their homecare to control periodontal disease.[51] New finger prick tests have been approved by the Food and Drug Administration in the US, and are being used in dental offices to identify and screen people for possible contributory causes of gum disease, such as diabetes.
In some people, gingivitis progresses to periodontitis – with the destruction of the gingival fibers, the gum tissues separate from the tooth and deepened sulcus, called a periodontal pocket. Subgingival microorganisms (those that exist under the gum line) colonize the periodontal pockets and cause further inflammation in the gum tissues and progressive bone loss. Examples of secondary causes are those things that, by definition, cause microbic plaque accumulation, such as restoration overhangs and root proximity.
Smoking is another factor that increases the occurrence of periodontitis, directly or indirectly,[52][53][54] and may interfere with or adversely affect its treatment.[55][56][57] It is arguably the most important environmental risk factor for periodontitis. Research has shown that smokers have more bone loss, attachment loss and tooth loss compared to non-smokers.[58] This is likely due to several effects of smoking on the immune response including decreased wound healing, suppression of antibody production, and the reduction of phagocytosis by neutrophils[58]
Ehlers–Danlos syndrome and Papillon–Lefèvre syndrome (also known as palmoplantar keratoderma) are also risk factors for periodontitis.
If left undisturbed, microbial plaque calcifies to form calculus, which is commonly called tartar. Calculus above and below the gum line must be removed completely by the dental hygienist or dentist to treat gingivitis and periodontitis. Although the primary cause of both gingivitis and periodontitis is the microbial plaque that adheres to the tooth surfaces, there are many other modifying factors. A very strong risk factor is one's genetic susceptibility. Several conditions and diseases, including Down syndrome, diabetes, and other diseases that affect one's resistance to infection, also increase susceptibility to periodontitis.
Periodontitis may be associated with higher stress.[59] Periodontitis occurs more often in people in the lower classes than people in the upper classes.[60]
Genetics appear to play a role in determining the risk for periodontitis. It is believed genetics could explain why some people with good plaque control have advanced periodontitis, whilst some others with poor oral hygiene are free from the disease. Genetic factors which could modify the risk of a person developing periodontitis include:
Diabetes appears to exacerbate the onset, progression, and severity of periodontitis.[61] Although the majority of research has focused on type 2 diabetes, type 1 diabetes appears to have an identical effect on the risk for periodontitis.[62] The extent of the increased risk of periodontitis is dependent on the level of glycaemic control. Therefore, in well managed diabetes there seems to be a small effect of diabetes on the risk for periodontitis. However, the risk increases exponentially as glycaemic control worsens.[62] Overall, the increased risk of periodontitis in diabetics is estimated to be between two and three times higher.[61] So far, the mechanisms underlying the link are not fully understood, but it is known to involve aspects of inflammation, immune functioning, neutrophil activity, and cytokine biology.[62][63]
Mechanism[edit]
As dental plaque or biofilm accumulates on the teeth near and below the gums there is some dysbiosis of the normal oral microbiome.[64] As of 2017 it was not certain what species were most responsible for causing harm, but gram-negative anaerobic bacteria, spirochetes, and viruses have been suggested; in individual people it is sometimes clear that one or more species is driving the disease.[64] Research in 2004 indicated three gram negative anaerobic species: Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Bacteroides forsythus and Eikenella corrodens.[58]
Plaque may be soft and uncalcified, hard and calcified, or both; for plaques that are on teeth the calcium comes from saliva; for plaques below the gumline, it comes from blood via oozing of inflamed gums.[64]
The damage to teeth and gums comes from the immune system as it attempts to destroy the microbes that are disrupting the normal symbiosis between the oral tissues and the oral microbe community. As in other tissues, Langerhans cells in the epithelium take up antigens from the microbes, and present them to the immune system, leading to movement of white blood cells into the affected tissues. This process in turn activates osteoclasts which begin to destroy bone, and it activates matrix metalloproteinases that destroy ligaments.[64] So, in summary, it is bacteria which initiates the disease, but key destructive events are brought about by the exaggerated response from the host's immune system.[58]
Daily oral hygiene measures to prevent periodontal disease include:
Typically, dental hygienists (or dentists) use special instruments to clean (debride) teeth below the gumline and disrupt any plaque growing below the gumline. This is a standard treatment to prevent any further progress of established periodontitis. Studies show that after such a professional cleaning (periodontal debridement), microbial plaque tends to grow back to precleaning levels after about three to four months. Nonetheless, the continued stabilization of a person's periodontal state depends largely, if not primarily, on the person's oral hygiene at home, as well as on the go. Without daily oral hygiene, periodontal disease will not be overcome, especially if the person has a history of extensive periodontal disease.
Prognosis[edit]
If people have 7-mm or deeper pockets around their teeth, as measured by a periodontal probe, then they would likely risk eventual tooth loss over the years. If this periodontal condition is not identified and people remain unaware of the progressive nature of the disease, then years later, they may be surprised that some teeth will gradually become loose and may need to be extracted, sometimes due to a severe infection or even pain.
According to the Sri Lankan tea laborer study, in the absence of any oral hygiene activity, approximately 10% will experience severe periodontal disease with rapid loss of attachment (>2 mm/year). About 80% will experience moderate loss (1–2 mm/year) and the remaining 10% will not experience any loss.[83][84]
History[edit]
An ancient hominid from 3 million years ago had gum disease.[88] Records from China and the Middle East, along with archaeological studies, show that mankind has had periodontal disease for at least many thousands of years. In Europe and the Middle East archaeological research looking at ancient plaque DNA, shows that in the ancient hunter-gatherer lifestyle there was less gum disease, but that it became more common when more cereals were eaten. The Otzi Iceman was shown to have had severe gum disease. Furthermore, research has shown that in the Roman era in the UK, there was less periodontal disease than in modern times. The researchers suggest that smoking may be a key to this.[89]
Society and culture[edit]
Etymology[edit]
The word "periodontitis" (Greek: περιοδοντίτις) comes from the Greek peri, "around", odous (GEN odontos), "tooth", and the suffix -itis, in medical terminology "inflammation".[90] The word pyorrhea (alternative spelling: pyorrhoea) comes from the Greek pyorrhoia (πυόρροια), "discharge of matter", itself from pyon, "discharge from a sore", rhoē, "flow", and the suffix -ia.[91] In English this term can describe, as in Greek, any discharge of pus; i.e. it is not restricted to these diseases of the teeth.[92]
Economics[edit]
It is estimated that lost productivity due to severe periodontitis costs the global economy about US$54 billion each year.[93]
Other animals[edit]
Periodontal disease is the most common disease found in dogs and affects more than 80% of dogs aged three years or older. Its prevalence in dogs increases with age, but decreases with increasing body weight; i.e., toy and miniature breeds are more severely affected. Recent research undertaken at the Waltham Centre for Pet Nutrition has established that the bacteria associated with gum disease in dogs are not the same as in humans.[94] Systemic disease may develop because the gums are very vascular (have a good blood supply). The blood stream carries these anaerobic micro-organisms, and they are filtered out by the kidneys and liver, where they may colonize and create microabscesses. The microorganisms traveling through the blood may also attach to the heart valves, causing vegetative infective endocarditis (infected heart valves). Additional diseases that may result from periodontitis include chronic bronchitis and pulmonary fibrosis.[95]