The sphenoid bone is one of the most fascinating bones in the body. If you were looking at someone and could see their bones, the sphenoid would be behind their eyes and in front of their ears, with the outermost parts (the greater wings) accessible at the temples, and the lowermost parts (the pterygoid processes) being what your internal jaw muscles attach to behind your upper back teeth.
The word sphenoid comes from the Greek for wedge-shaped. Its shape has been likened to a moth, a bat, a butterfly, and a wasp.
Here’s a picture of it, as viewed from the front.
It’s a central cranial bone that does many important things:
- it connects to your internal jaw muscles
- muscles involved in swallowing are attached to it
- it helps form the orbits of your eyes
- the optic nerves meet, cross, and pass through it
- your pituitary (master gland) sits on top of it (in the “sella Turcica” — Turkish saddle!)
- it contains two air sinuses, the sphenoidal sinuses, which open into the nasal cavity through the ethmoid bone
- it has openings for major blood vessels and nerves of the head and neck
- the tentorium cerebelli, part of the membranous system surrounding the central nervous system, attaches to it
The sphenoid has been called the keystone bone of the skull. It touches 12 other cranial bones: the two parietals, two temporals, two zygomas, two palatines, the frontal, occipital, ethmoid, and vomer.
The place where the sphenoid and occiput meet is called the sphenobasilar joint (SBJ). (The occiput is considered the base of the cranium.)
You can see the SBJ in the middle of the image below where the orange and yellow bones meet.
The alignment of this joint is important. William Sutherland, DO, father of cranial osteopathy, believed that the rest of the skeletal system moves to accommodate the SBJ. If the two bones of the joint are not aligned well, it can affect the endocrine, nervous, and cardiovascular systems.
Misalignment of the SBJ can obviously affect other cranial bones, which fit closely together, something like a spherical jigsaw puzzle.
When the SBJ is misaligned, it affects the jaw. (Remember, your internal jaw muscles attach to it.)
It is also a consideration in migraines, headaches, sinus problems, pain in the head, neck, and back, scoliosis, eye movement, and problems with behavior, personality, learning, coordination, hormones, and emotions.
This is how the sphenoid bone can affect the structure of the body. Craniosacral therapists pay a lot of attention to the sphenoid and can gently move it into better alignment.