Oral and Craniofacial Diseases and Disorders

Dental caries develops by the localized dissolution of the tooth hard tissues, caused by acids that are produced by bacteria in the biofilms (dental plaque) on the teeth and eventually lead to “cavities.” The biofilm consists of microorganisms, including the highly cariogenic mutans streptococci, and a matrix made up mainly of extracellular polysaccharides. The destructive acids are produced when fermentable carbohydrates (sugars) reach these biofilms, each episode resulting in tooth damage (attack). If this process does not occur frequently, then the natural capacity of the body (through saliva) to remineralize will prevent formation of a cavity. Thus, the main risk factors include presence of cariogenic biofilms and frequent consumption of fermentable carbohydrates. Exposure to fluorides in optimum concentrations reduces the risk, and normal saliva flow and saliva protective systems are also important to counteract the cariogenic factors. Untreated caries can give rise to infection of the tooth pulp, which can spread to the supporting tissues and the jaws, culminating in advanced disease conditions that are often painful. For example, in Thailand, recent surveys of a sample of 12-year-old children revealed that 53 percent had suffered from pain or discomfort from teeth over the past year (Petersen and others 2001). The corresponding figures in China were 34 percent for 12-year-olds (Peng, Petersen, Fan, and others 1997) and 74 percent for adults (Petersen, Peng, and Tai 1997). Tooth decay is a public health problem worldwide. According to the U.S. Surgeon General’s report (U.S. Public Health Service 2000), dental caries is the single most common chronic childhood disease in the United States. Epidemiological data for almost 200 countries are available in the World Health Organization (WHO) Country/Area Profile Programme (CAPP) oral health database (http://www.whocollab.od.mah. se/index.html) (see table 38.1 for examples). Caries prevalence of permanent teeth is expressed by the decayed, missing, and filled teeth (DMFT) index (calculated by counting the number of DMFT of individuals and taking the mean for the group examined). One indicator age group used for international comparisons is 12-year-old children. The WHO oral health goal was to achieve three DMFT or fewer among 12-year-olds Chapter 38 Oral and Craniofacial Diseases and Disorders