[The Bayesian framework of detection of cariesgenic Streptoccocus in dental plaque in children with distal occlusion under orthodontic treatment].

The application of Bayes theorem in medical diagnostic includes such important step as derivation for every symptom and diagnosis data values of finite or a posteriori probability of presence of germ, for instance S. sanguis, in patients receiving orthodontic treatment. This value expresses importance of the given symptoms for detection of germ presence. In the implemented studies the Bayes theorem was applied to evaluate probability of presence of particular germ in particular concentration (degree of semination, CO) under concrete symptom group. The rates were used to calculate probability of presence of cariesgenic streptococcus S. mutans and S. sanguis in prospect patient. The rates were calculated for the group with fixed orthodontic apparatuses. The high degree of risk of development of caries in children under orthodontic treatment is conditioned by a whole complex of existing unfavorable factors present in oral cavity. Hence, a powerful negative potential to develop expressed cariesgenic situation in oral cavity is present. The analysis of medical data of patients with distal occlusion was applied using Bayes theorem from the point of view their diagnostic value. The study established 36 symptoms, factors, risk factors and background diseases common in case of distal occlusion in children. The probability to detect the mentioned characteristics and likelihood ratio under different degree of concentration of cariesgenic Streptococcus mutans and Streptococcus sanguis in dental plaque of children was considered. The establishment of character of likelihood ratio for different qualitative content of streptococcus in case of isolation from biotope of dental plaque permitted to determine the informative characteristics. The Bayesian model can be applied in clinics as a computer program to process incoming information about patients with distal occlusion under active orthodontic treatment. The developed diagnostic algorithm in a fast and simple mode of clinical detection of caries and determination of concentration of cariesgenic Streptococcus.