Fascia has been described as the stuff you cut through on the way to something important. One of the first things medical and dental students learn in practical anatomy is to remove the layers of fascia enclosing the muscles so that a muscle can be defined in terms of origin, insertion, line of action, blood and nerve supply etc. Figure 1 illustrates the point nicely. This image carries over into the clinical world of surgery where fascia is seen primarily as an inconvenience.
Fascia comes in many guises. It is composed chiefly of collagen and ground substance plus fibres like reticulin which help give it elasticity. Rather than thinking of all the different forms of fascial tissue as separate entities (e. g. ligaments, tendons, aponeuroses, intracranial membranes etc.) fascia is now considered as a single organ, permeating all the body and reaching every cell by way of the extracellular matrix.
Fascia keeps organs anchored, it allows tissues to slide across or past each other, it contains blood vessels and nerves. More recently fascia has been recognized for its role as a communication system, enabling the passage of energy/information through all the body much faster than a nerve reaction.
Figure 2 illustrates how we now have to think of the body. Not as separate parts, vaguely connected but as one unit. A continuum of myofascial tissue runs from the heel up across the pelvis and the back, over the cranium via the cranial aponeurosis to attach to the frontal bone just above the bony orbits. This forms an integral part of body mechanics. An awareness of change in any part of this system is very rapidly conveyed to all the other components.
We can no longer think of the mouth as a zone of activity separate from the rest of the body. What happens in the mouth has direct consequences outside the mouth. It may be so insignificant that it is easily absorbed but in many instances it has recognizable ramifications or sequelae.
Similarly, extraoral changes in structure or behavior can feed directly into oral reaction. Oral behavior in the effort to obtain maximum effort shows how interconnected the mouth can be. The implications for dentistry and especially orthodontics are profound.