**4. Microbiological involvement**

The severe infections of odontogenic origin frequently involve a complex polymicrobial mix of aerobes, facultative aerobes and strict anaerobes working together. Some species like *Peptostreptococcus, Staphylococcus, Lactobacillus, Prevotella, Treponema, Fusobacterium, Veillonella, Actinomyces, Bacteroide s*sp. and oral *Streptococcus* sp. are frequently associated with infections of odontogenic origin.[13, 36, 43, 46, 48, 56] Sakamoto et al., reported 17 different species collected from a single surgical site.[48] Flynn et al., isolated 90 different strains of microor‐ ganisms in 37 patients, and of these, 17 were penicillin-resistant.[13] Other species can be easily found at the infection sites, but generally, they reflect the indigenous microflora of the oral cavity. Routine culture and sensitivity testing for minor oral infections does not appear to be justified, however, when an infection involves anatomic spaces of moderate or greater severity, or when there is significant medical/immune compromise, the tests become important to the outcome.
