The skull bones move rhythmically and are the basis for normal hypothalamic reserves.
Plagiocephaly is defined in the dictionary as "crooked head". It isn't the best description of what is happening but is the best one presently being used. I guess a better one would be Cranial Dysarthria (abnormal interrelationships of the cranial joints). Here is the story:
In the 1940s, a brilliant Osteopath discovered that the 22 bones that make up the cranium are in constant motion. This had been missed by the rest of the medical profession since we study the skull in the dead human and, in that condition, they ARE unmoving. I know this may sound pretty silly but many historical breakthroughs in "medical" discovery were JUST as obvious after someone pointed it out to the profession.
First of all, no mechanism for the circulation of the cerebrospinal fluid (which provides about 75% of the nutrients needed for the survival of the central nervous system (CNS)) had ever been discovered prior to the insight of the osteopath in the '40s. He found that the skull bones expanded and contracted about 15 times a minute in a process which has been called the "primary respiratory mechanism". It tends to be synchronous with the "secondary respiratory mechanism"--breathing--that we are all aware of. However, even if we hold our breath, the skull pulsation continues by itself. There are valves in the brain that allow the fluid to only move in one direction so the expansion and contraction of the skull bones (although very slight) provide the only motive power needed to circulate this fluid.
The concept of the rigid skull is so ingrained in the medical psyche that now, 50 years later, it STILL is taught as a rigid box with no known mechanism for the circulation of the CNS fluid. This stupidity is perpetuated even though we ALL accept the fact that ANY bones that meet at a joint will begin to fuse if they are held in one position for even a month or so. Yet, the cranial bones do not fuse. Of course, knowledgeable professionals know that is because the incredibly complex joints in the skull are in constant motion.
A common cause of the restriction of the normal movement is bracing. However, one of the complications of that bracing is TMJ and TMJ DIRECTLY works to lock the cranial bones in place. Anyone can demonstrate the devastating effect of this locking by using a simple resistance meter (the spring things weight lifters use to test their strength of grip). Make sure your teeth do not touch for about 5 minutes and test your strength WHILE your teeth are not touching. Write down the result. Then, test your strength after your teeth have been touching for a minute WHILE your teeth are touching. It makes no difference in what order you do the above. One can get a good laugh out of watching a hidebound conventional medical practitioner try to explain what is observed. The same reduction of your immune reserves and stress management capacity of the hypothalamus occur at the same time as the muscle strength disappears. Of course, I am just skimming the surface of this subject here.
Finally, remember that your skull bones do not include the jawbone since they come from totally different origins during fetal development. There is no joint in the middle of the jawbone whereas there is one in the middle of the roof of your mouth (to allow for the pumping motion of the skull). If your teeth just touch, the skull movement is locked in place as long as the teeth are in contact. TMJ is a FAR ADVANCED complication of the habitual allowing the teeth to touch. There is a well known mechanism that explains why habitual "teeth touching" inevitably progresses to TMJ but it is beyond the scope of this page.
A Certified Cranial Osteopath would know how to get the skull bones moving again. Call The Cranial Academy, at (317) 594-0411 for information AND the closest Certified Cranial Osteopath for diagnosis and gentle manipulative treatment (should that be indicated).