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.
By the way, 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) sit on top of it (in a 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 down to the sacrum, attaches to the sphenoid
The sphenoid has been called the keystone bone. It touches 12 other cranial bones: two parietals, two temporals, two zygomas, two palatines, 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 are not aligned well, it can affect the endocrine, nervous, and cardiovascular systems as well.
Misalignment of the SBJ can obviously affect other cranial bones, which fit closely together. It can contribute to TMJ pain and dysfunction.
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 and allergies, pain in the head, neck, and back, scoliosis, issues with eye movements, 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. I like to end TMJ Relief sessions with a gentle adjustment to the sphenoid and a stillpoint to let the body integrate the new alignment.