Formation and ecology of plaque at different locations in the mouth

Cutaneous and Extracutaneous Manifestations of Behçet's Disease Linked to Its Disease Activity and Prognosis

Background

Behçet’s disease is a potentially fatal vasculitis disorder involving vessels in both the arterial and venous systems. Cutaneous manifestation is the most common sign in Behçet’s disease, but its relation to disease activity and prognosis is lacking.

Objective

Our study aims to determine the relationship between cutaneous, extracutaneous manifestations with Behçet’s disease activity, morbidity, and mortality.

Materials and Methods

Patients diagnosed with Behçet’s disease were identified by using the 1990 International Study Group for Behçet’s disease criteria and/or the 2014 international criteria for Behçet’s disease. Data regarding patients’ clinical manifestations, laboratory results, disease activity, and prognosis were retrieved and analyzed. Disease activity was evaluated using the 2006 Behçet’s disease current activity form (BDCAF).

Results

Of 119 patients, the mean age at diagnosis was 35.7 ± 10.7 years and 60% were female. Median disease duration was 96 months (IQR 48–168). Minor oral ulcer at the buccal mucosa was associated with lower median BDCAF score (p = 0.003), whereas minor oral ulcer at the tonsil was related to higher BDCAF score (p = 0.024). Male gender was associated with higher cumulative dose of corticosteroids (p = 0.003) and hospitalization (OR = 2.89 (95% CI [1.10, 7.57]), p = 0.031). Ocular manifestations were related to higher dose of corticosteroids (p = 0.002) and morbidity (OR = 4.39 (95% CI [1.57, 12.29]), p = 0.005).

Conclusion

Our study suggests that different locations of minor oral ulcers help predict disease activity. Male gender and the presence of ocular manifestations resulted in less favorable outcomes for Behçet’s disease.

A mixed-bacteria ecological approach to understanding the role of the oral bacteria in dental caries causation: an alternative to Streptococcus mutans and the specific-plaque hypothesis

For more than 100 years, investigators have tried to identify the bacteria responsible for dental caries formation and to determine whether their role is one of specificity. Frequent association of Lactobacillus acidophilus and Streptococcus mutans with caries activity gave credence to their being specific cariogens. However, dental caries occurrence in their absence, and the presence of other bacteria able to produce substantial amounts of acid from fermentable carbohydrate, provided arguments for non-specificity. In the 1940s, Stephan found that the mixed bacteria in dental plaque produced a rapid drop in pH following a sugar rinse and a slow pH return toward baseline. This response became a cornerstone of plaque and mixed-bacterial involvement in dental caries causation when Stephan showed that the pH decrease was inversely and clearly related to caries activity. Detailed examination of the pH (acid-base) metabolisms of oral pure cultures, dental plaque, and salivary sediment identified the main bacteria and metabolic processes responsible for the pH metabolism of dental plaque. It was discovered that this metabolism in different individuals, in plaque in different dentition locations within individuals, and in individuals of different levels of caries activity could be described in terms of a relatively small number of acid-base metabolic processes. This led to an overall bacterial metabolic vector concept for dental plaque, and helped unravel the bacterial involvement in the degradation of the carbohydrate and nitrogenous substrates that produce the acids and alkali that affect the pH and favor and inhibit dental caries production, respectively. A central role of oral arginolytic and non-arginolytic acidogens in the production of the Stephan pH curve was discovered. The non-arginolytics could produce only the pH fall part of this curve, whereas the arginolytics could produce both the fall and the rise. The net result of the latter was a less acidic Stephan pH curve. Both kinds of bacteria are numerous in dental plaque. By varying their ratios, we were easily able to produce Stephan pH curves indicative of different levels of caries activity. This and substantial related metabolic and microbial data indicated that it is the proportions and numbers of acid-base-producing bacteria that are at the core of dental caries activity. The elimination of S. mutans, as with a vaccine, was considered to have little chance of success in preventing dental caries in humans, since, in most cases, this would simply make more room for one or more of the many acidogens remaining. An understanding of mixed-bacterial metabolism, knowledge of how to manipulate and work with mixed bacteria, and the use of a bacterial metabolic vector approach as described in this article have led to (1) a more ecological focus for dealing with dental caries, and (2) new means of developing and evaluating anti-caries agents directed toward microbial mixtures that counter excess acid accumulation and tooth demineralization.