The Oral cavity is the gateway for food and is the outpost of the immune system.Its a multilayered habitat where colonies of microorganisms inhabit.
Microorganisms are a part of our lives in more way than one.They have helped shaped the present environment as well as its activities and will greatly influence our future.
The mouth is continually exposed to organisms from the external environment.When the ecological balance of the microorganisms gets established,it helps to create a resident microbial flora in the oral cavity that remains fairly stable throughout life.
ORAL ECOSYSTEM
It has long been known that oral bacteria preferentially colonize on different surfaces in the oral cavity,due to specific adhesions on bacterial surface which aid in binding to complementary specific receptors on a given oral surface.
NORMAL FLORA IN HUMAN ORAL CAVITY
Presence of nutrients,epithelial debris and secretions,along with hospitable temperature makes the mouth a favorable habitat for great variety of bacteria like Streptococci,Lactobacilli,Staphylococci etc.
Buccal epithelium of the oral cavity contains flora like Streptococcus mutans and Streptococcus sanguinis.Hard palate consists of respiratory tract bacteria like Corynebacterium and Neisseria.Dorsum of the tongue also contains more number of gram positive filaments of Streptococcus sailavarius.
MICROBIAL FLORA AT DIFFERENT STAGES OF LIFE
At birth
The mouth of a full term fetus is sterile.'Transient Flora' from birth canal may be accquired.Accquires microbes like :
1. Lactobacillus.
2. Neisseria.
3. Yeasts.
Infancy and Early Childhood
Infants come into contact with an ever increasing range of microbes and some of them become established as a part of commensal flora.Eruption of deciduous teeth provide a new attachment surface and turns Streptococcus sanguis and mutans as regular inhabitants.
Adolescence
A great number of microbes will inhabit the mouth when permanent teeth erupt,since they have deeper fissures,larger proximal spaces,and deeper gingival crevices allowing greater increase in anaerobes.
Adulthood
Bacteroides and Spirochetes are seen in dental palque.
Edentulous stage
Less number of bacteriodes or Spirochetes in the oral cavity,but there will be increase in the carriage of yeasts.
Other microbes in the oral cavity
1.Parasites
2.Fungi
PREVENTIVE APPROACH
Brushing and Flossing .Will help get rid of the bacteria which stick to the tooth surface that allows the formation of dental plaque.
CONCLUSION
There are a wide variety of organisms present in the oral cavity each with distinctive properties.These organisms help determine the ways in which they react with their hosts; whether it will contribute to oral health or morbidities .
Therefore, the identification of the ratio of microbes at different phases of a medical condition is challenging.