Sidebar: The 21st-Century Mouth: A Window into Our Health

Why study the mouth? The term "oral cavity" belies the rich potential of this organ as a scientific playground and powerful tool for probing human health.

The oral cavity is an excellent model for studying complex systems. Home to a sophisticated set of functions, every second of every day the mouth exhibits a dynamic interplay between sensation, mechanical function and chemical flux. Multiple tissue types--including bone, nerves and blood--confront a bacterial zoo, crushing mechanical forces and electrical currents.

Microbial Laboratory. A healthy human mouth is home to an enormous variety of microorganisms, including viruses, fungi, protozoa and bacteria. The bacteria alone dominate this scene: Hundreds of millions live in a drop of saliva, accounting for about 1,500 different species in total. Research on this oral microbiome, which is likely to be unique to each individual, will offer the opportunity to look at a range of health issues including nutrition, infections and risk for cancer and other diseases.

Bone Remodeling. Bones of the head and face come in all shapes and sizes. They are subject to a wide range of mechanical loads and physical forces, rather unlike skeletal bones that are more linear in structure and function. Research on craniofacial bone structure and function offers the opportunity to convey lessons learned to more tailored rehabilitation of other bones in the body.

Joint Disorders and Pain. Temporomandibular muscle and joint disorders are a painful group of conditions afflicting many people in the U.S. But they are also a model system for understanding the complex interactions between sensation, mechanical forces, and tissue and immune function. Understanding temporomandibular muscle and joint disorders holds promise for understanding and treating other complex disorders such as chronic fatigue syndrome, fibromyalgia and chronic pain.

Drug Delivery. The salivary gland serves many functions: secreting proteins and hormones, and of course, keeping our mouth moist. But as a research tool, the salivary gland is a sophisticated bioreactor that may be used to deliver drugs, genes, proteins or other molecules to the bloodstream. It is also a valuable model for understanding basic glandular function—and thus can deepen understanding of how other glands and organs work—the pancreas, lungs, mammary glands and kidneys, for example.

Above all, the mouth is easy to get to—a uniquely tractable system and an excellent window into health and disease.