Seminar Periodontal Diseases
Total Page：16
File Type：pdf, Size：1020Kb
Seminar Periodontal diseases Bruce L Pihlstrom, Bryan S Michalowicz, Newell W Johnson The periodontal diseases are highly prevalent and can affect up to 90% of the worldwide population. Gingivitis, the Lancet 2005; 366: 1809–20 mildest form of periodontal disease, is caused by the bacterial biofilm (dental plaque) that accumulates on teeth Center for Clinical Research, adjacent to the gingiva (gums). However, gingivitis does not affect the underlying supporting structures of the teeth National Institute of Dental and is reversible. Periodontitis results in loss of connective tissue and bone support and is a major cause of tooth loss and Craniofacial Research, National Institutes of Health, in adults. In addition to pathogenic microorganisms in the biofilm, genetic and environmental factors, especially Bethesda, MD 20892-6401, tobacco use, contribute to the cause of these diseases. Genetic, dermatological, haematological, granulomatous, USA (B L Pihlstrom DDS); immunosuppressive, and neoplastic disorders can also have periodontal manifestations. Common forms of Division of Periodontology, periodontal disease have been associated with adverse pregnancy outcomes, cardiovascular disease, stroke, pulmonary School of Dentistry, University of Minnesota, disease, and diabetes, but the causal relations have not been established. Prevention and treatment are aimed at Minneapolis, MN, USA controlling the bacterial biofilm and other risk factors, arresting progressive disease, and restoring lost tooth support. (B S Michalowicz DDS); and Griffith University School of Any inherited or acquired disorder of the tissues Cause Dentistry and Oral Health Griffith University Gold Coast surrounding and supporting the teeth (periodontium) Oral microorganisms campus, Southport, can be defined as a periodontal disease. These diseases The mouth, like all external surfaces of the body and the Queensland, Australia may be of developmental, inflammatory, traumatic, gut, has a substantial microflora living in symbiosis with (N W Johnson MDSc) neoplastic, genetic, or metabolic origin (table).1,2 a healthy host. The microflora of the mouth contains Correspondence to: However, the term periodontal disease usually refers to hundreds of species of aerobic and anaerobic bacteria. Dr Bruce Pihlstrom [email protected] the common inflammatory disorders of gingivitis and These organisms grow on tooth surfaces as complex, periodontitis that are caused by pathogenic microflora in mixed, interdependent colonies in biofilms, and are the biofilm or dental plaque that forms adjacent to the attached and densely packed against the tooth in the teeth on a daily basis. Gingivitis, the mildest form of deeper layers, with more motile forms in the superficial periodontal disease, is highly prevalent and readily layers.9 Cultural studies indicate that more than reversible by simple, effective oral hygiene. Gingivitis 500 distinct microbial species can be found in dental affects 50–90% of adults worldwide, depending on its plaque.10 However, molecular methods of 16S rDNA precise definition.3 amplification reveal an even more diverse view of the Inflammation that extends deep into the tissues and subgingival bacterial flora and suggest that a large causes loss of supporting connective tissue and alveolar proportion of even this well-studied and familiar bone is known as periodontitis (figure 1). Periodontitis microbial environment remains uncharacterised.11,12 As results in the formation of soft tissue pockets or dental plaque matures to a state that is associated with deepened crevices between the gingiva and tooth root. periodontal disease, the number of gram-negative and Severe periodontitis can result in loosening of teeth, anaerobic bacteria increases.13–16 Bacterial counts above occasional pain and discomfort, impaired mastication, the gums (supragingival) on one tooth surface can and eventual tooth loss. exceed 1ϫ109 bacteria. Below the gum, the number of Although prevalence estimates differ on the basis of bacteria ranges from 1ϫ103 in a healthy shallow crevice how the disease is defined, the prevalence, severity, and to more than 1ϫ108 in a periodontal pocket.17 Tooth rate of disease progression clearly varies worldwide.4,5 cleanings every 48 h can maintain the biofilm mass Periodontitis is generally more prevalent in developing countries,6 although disease may not necessarily be Search strategy and selection criteria extensive or severe in indigenous populations.7 One The MEDLINE database was searched by use of PubMed to identify articles containing large survey estimated that about 22% of US adults had “periodontal”, as well as specific periodontal diseases and associated conditions, or causal mild disease and 13% had moderate or severe disease.8 or risk factors discussed in this Seminar. As additional sources and crosschecks for the In the USA, periodontitis is consistently more prevalent reliability of the search strategy, we reviewed comprehensive textbooks on in men than women, and in black and Mexican- periodontology. Americans than white people.8 Diseases caused by periodontal biofilm Diseases with periodontal manifestations Genetic disorders with periodontal manifestations Gingivitis (acute/chronic): May be exacerbated by Diabetes, lichen planus, pemphigoid, pemphigus, leukaemia, neutropenia, Familial and cyclic neutropenias; granulomatous disease; pregnancy, diabetes, puberty, contraceptives, ascorbic Wegener’s granulomatosis, erythema multiforme, candidiasis, HIV/AIDS, agranulocytosis; Langerhans’ cell disease; glycogen storage disease; acid deprivation, menstruation psoriasis, tuberculosis, gonorrhoea, primary and recurrent herpes simplex hypophosphatasia; and leucocyte adhesion deficiency, Periodontitis (acute/chronic): Mostly occurs in adults infection, lupus erythematosus, histoplasmosis, linear IgA disease Papillon-Lefèvre, Chédiak-Higashi, Cohen, Ehlers-Danlos, Marfan’s, as a slowly progressive chronic disease, but could be primary and metastatic carcinoma, Crohn’s disease, drug-associated Down’s, Haim-Munk, and Kindlers syndromes rapidly progressive and occur in children gingival enlargement Table: Periodontal diseases www.thelancet.com Vol 366 November 19, 2005 1809 Seminar deciduous and permanent teeth. These syndromes are caused by mutations in the cathepsin C gene.32–34 Prepubertal periodontitis in some families could represent partly penetrant Papillon-Lefèvre syndrome.35 Other disorders that have severe periodontal manifestations include Chédiak-Higashi, Ehlers-Danlos (types 4 and 8), Kindlers, and Cohen syndromes. Data from twin studies indicate that about half the population variance in periodontitis can be attributed to genetic factors.36–39 Moreover, accumulating evidence shows that genetic variations in or near cytokine genes could affect the systemic inflammatory response in people with periodontitis.40,41 Although several genetic polymorphisms have been associated with periodontal disease, not enough evidence at present supports the widespread use of genetic tests to either assess risk for disease or predict treatment response.42,43 Figure 1: Surgical exposure of bone loss (arrow) resulting from periodontitis adjacent to a maxillary anterior tooth Tobacco and alcohol use Smokers are much more likely than non-smokers to at an amount compatible with gingival health.18 develop periodontitis.44 Moreover, oral smokeless Unfortunately, few individuals achieve this, and tobacco can lead to gingivitis, loss of tooth support, and exhortations to the public to clean teeth more thoroughly precancerous gingival leucoplakia at the site of quid are generally ineffective in public-health care.19 placement.45–48 The risk of periodontal disease in long- An enormous research effort has been devoted to the term smokers is equal to that of lung cancer, and study of periodontal-disease-associated microflora, from smoking has a strong negative effect in response to classic cultural methods to modern approaches on the periodontal treatment and other oral surgical molecular, whole genomic, and proteomic level.20,21 interventions.44 In the USA, about half the risk of Certain clusters of bacterial species commonly cohabit periodontitis can be attributable to smoking.49,50 By subgingival sites and are reproducibly associated contrast with tobacco use, a small but significant with disease.22 These putative pathogens include association exists between alcohol consumption and loss Porphyromonas gingivalis, Tannerella forsythensis, and the of periodontal support.51 spirochaete Treponema denticola. Infection of periodontal tissues with these and other organisms is accompanied HIV and AIDS by the release of bacterial leucotoxins, collagenases, Although HIV disease has a relatively minor effect on fibrinolysins, and other proteases.23 Actinobacillus the progression of chronic periodontitis compared with actinomycetemcomitans is another species commonly other pathogenic factors,52 patients who are HIV-positive associated with disease, especially in young adults.24,25 and immunosuppressed can present with distinctive Recent work implicates herpes viruses in the forms of necrotising gingivitis and periodontitis.53 Acute pathogenesis of periodontitis26–28 and Candida albicans necrotising ulcerative gingivitis was formerly known as and other fungi in immunocompromised individuals.29 trench mouth, because of its high prevalence in the Clearly, a variety of microorganisms can contribute trenches of World War I, when stress, fatigue, differently in populations and individuals in the malnutrition,