The Relationship Between the Spine, Cranium and TMJ
Charles L. Blum, DC
© 2004 Sacro Occipital Technique Organization – USA

In the chiropractic field cranial manipulation or craniopathy and temporomandibular joint (TMJ) therapies are not “stand-alone” techniques. What this means is that to properly treat the cranium or TMJ the spine must be evaluated and treated for neuromusculoskeletal matrix dysfunction or subluxations. Tensions upon the meningeal and myoligamentous aspects of the spine affect the central nervous system directly. For this reason, the adjustment and balancing of the spine and pelvis is always primary to any cranial or TMJ condition. Literature published in chiropractic journals have found relationships between the TMJ, cervical ¹ and lumbar spine ², as well as a relationship between the sacroiliac joint and TMJ ³. In each case the spine had a primary role in treatment. Chiropractic literature has also discussed how cranial therapy or craniopathy is incumbent upon the balancing of spine and pelvis. ^4,5

The dura mater is a tough fibrous membrane. It is the outermost covering of the brain and the spinal cord. The dura of the brain and that of the spinal cord are similar and continuous with one another at and through the foramen magnum. The dura mater is the outermost envelope of the central nervous system,. However, within the cranium aside from surrounding the cerebrum and cerebellum, the dura mater also compartmentalizes each structure and separates one from another and the right from the left side. The external layer serves as the internal periosteum for the cranial bones and is continuous through the sutures with the periosteum of the external surface of the skull where it anchors and attaches itself. The internal meningeal layer has four folds; the falx cerebri, the tentorium cerebelli, the falx cerebelli, and the diaphragma sellae. The dura anchors strongly to the different areas of the inner cranial vault especially where the meningeal layer comes in contact with the periosteal layer. ^6-16

The cranial dura is firmly adherent to the different points within the cranium, to the ring of the atlas and extends as the spinal dura having firm attachments to the foramen magnum, second and third cervical vertebrae. The posterior cervical epidural ligaments anchor the posterior dura mater to the ligamentum flavum.¹⁷ A connective tissue bridge also has been noted between the rectus capitis posterior minor muscle and the dorsal spinal dura at the atlanto-occipital junction. ¹⁸ Continuity was also "observed between the ligamentum nuchae and the posterior cervical spinal dura as the latter passed deeply from the midline toward the dura, but only at the first and second cervical vertebral levels. The ligamentum nuchae also passed bilaterally on to the occipital bone as far as the sutures between the occiput and the temporal bones, approaching the inferior nuchal line superiorly."¹⁹

Meningovertebral ligaments (ligaments of Hofmann) are found along the spinal canal between the L5/S1 intervertebral level and cephalad up to T1. These ligaments appear to be more prevalent in the lumbar vertebral column but are also present throughout the thoracic vertebral column. It is theorized that the dural sac attachments to the posterior aspect of the vertebral bodies and the posterior longitudinal ligament could act to traction the dural sac in the event of nuclear bulge or herniation. ²⁰

The spinal dura is a cylindrical sheath, which surrounds the spinal cord and spinal nerve roots, which passes through the intervertebral foramina. Along with the other dural spinal attachments an external aspect of the spinal dura has attachments by fibrous slips to the posterior longitudinal ligament and to a fatty connective tissue layer called epidural fat. This separates it from the periosteum and provides additional cushioning for the spinal cord and nerves within the spinal cord. The various dural attachments allow stability, yet still enable flexibility. The lateral wall of the dura is stabilized internally to the pia mater and therefore also to the spinal cord by the denticulate ligament. The denticulate ligament attaches to the spinal dura at regular intervals from the foramen magnum to the conus medullaris by tooth-like extensions of the pia mater between each spinal nerve. ^6-16

The dura mater and pia mater extend and continue coverage of the ventral and dorsal roots of each spinal nerve. Immediately after the nerve emerges from the intervertebral foramen, the recurrent meningeal nerve branch re-enters the vertebral canal through the foramen where it supplies afferent fibers to the vertebrae and their ligaments and carries sympathetic postganglionic fibers to the blood vessels of the spinal cord and its membranes. ^6-16

Although the spinal cord usually extends only to the L1 vertebrae level, the dural covering continues to line the entire extent of the vertebral canal creating a large spinal fluid filled subarachnoid space. The spinal dura, which anchors itself firmly at the second sacral segment, continues down the sacral canal to the filum terminale, and extends downward to blend with the periosteum on the dorsum of the coccyx, where it fuses with the periosteum. 8 There it secures the caudal end of the spinal cord and is called the central ligament of the spinal cord. The central ligament assists in maintaining the cord in position during movements of the body. ^6-16

Breig has also noted a relationship between dynamic tensions within the craniospinal system. He found through his neurosurgical practice and research that meningeal connections to osseous structures and connective tissue create a normal balanced tension necessary for neurological health. He states that "from a biomechanical aspect the spinal cord ... cannot be considered in isolation but must be treated as a continuous tract of nervous and supporting tissues, from the mesencephalon to the conus medullaris." He refers to this relationship as the "pons-cord-tract". He continues, "the static and dynamic properties of the pons-cord-tract constitute a self-contained biomechanical compartment." He noted that during gross flexion and extension of the vertebral column the pons-cord -tract would respond by lengthening and shortening. He noted that during these spinal movements "the axons and blood vessels of the spinal cord undergo deformation similar to that of the cord as a whole". ⁸

Breig explains why vascular insufficiency would occur at the vertebral level regardless if there is too much or too little tension: "When the cord shortens axially the transverse channels running between the intersecting glial fibers are kept patent by these fibres; they can be seen in both sagittal and coronal sections. At the same time the tendency for the tissue investing the channels to collapse is also counteracted by the resistance of the collagen fibres in the walls of the channels. 

The channels running axially are also kept open by the collagen fibres which, when compressed axially, bend away from these perivascular channels and displace the tissue towards the surface of the pia mater." ⁸ When there is a failure in the pons-cord-tract to maintain this balance and excessive shortening occurs the "intersecting glial fibers" and "collagen fibres" can not keep the perivascular channels patent and a localized vasomotor response will present itself at the vertebral level under this increased stress (Figure #1) ⁸

Figure #1: Spinal Cord - Meningeal Tension and Spinal Vascularity

Breig further states, when there is lengthening or "stretching of the cord, the protective function of the collagen fibres comes into play in the reverse sequence. The axially running nerve-and glial fibres are then pulled around the transverse perivascular channels. The tendency for constriction of these channels is then counteracted by the sudden resistance of those collagen fibres of the rhomboid network, which run transversely and parallel to the channels. Narrowing of the axially coursing channels when stretched is presumably resisted by the stiffening collagen fibres running in the axial direction. The constrictive tendency of the stretched cord tissue is thus counteracted, and any lateral pressure on the blood-vessels is prevented." When there is a failure in the pons-cord-tract to maintain this balance and excessive lengthening occurs the "collagen fibres of the rhomboid network" and those "collagen fibres running in an axial direction" cannot keep the perivascular channels patent and a localized vasomotor response will present itself at the vertebral level under this increased stress. ⁸

The study of chiropractic cranial therapy or craniopathy and TMJ notes the importance of the spine and vertebra for maintaining health of the nervous system. Affects of vertebral dysfunction can be far reaching, beyond the local related joint and mechanical dysfunction. There have been recent findings of dural connections to the muscles and ligamentous structures in the spine. ^17-20 The dura’s connection directly to the pia mater, by way of the dentate ligament, is profound because the pia mater is firmly adherent to the spinal cord, thus creating a direct connection between the vertebra and central nervous system. Craniopathy and TMJ therapies seek to enhance the balancing of meningeal tensions and are used in conjunction with chiropractic spinal adjustment(s).

References

1. Vernon L, Ehrenfeld D, Treatment of temporomandibular joint syndrome for relief of cervical spine pain: case report Journal of Manipulative and Physiological Therapeutics. 1982 Jun; 5(2): 79-81.

2. Gregory T. Temporomandibular Disorder Associated with Sacroiliac Sprain Journal of Manipulative and Physiological Therapeutics. 1993 May; 16(4): 256-65.

3. Chinappi AS, Getzoff H, Chiropractic/Dental Cotreatment of Lumbosacral Pain with Temporomandibular Joint Involvement Journal of Manipulative and Physiological Therapeutics. 1996 Nov; 19(9): 607-12. 

4. Blum CL, Curl DD, " The Relationship Between Sacro-Occipital Technique and Sphenobasilar Balance. Part One: the Key Continuities, "Chiropractic Technique, Aug 1998; 10(3): 95-100. 

5. Peterson K.; A Review of Cranial Mobility, Sacral Mobility, and Cerebrospinal Fluid Journal of the Australian Chiropractic Association . 1982 Apr ; 12(3): 7-14.

6. Gardner E, Gray DJ, O'Rahilly R, Anatomy - A Regional Study of Human Structure, 3rd Edition, Philadelphia, Toronto, London, W.B. Saunders Company , 1969, 555-60.

7. Goss CM, Gray's Anatomy of the Human Body , 28th Edition, Philadelphia, Pennsylvania, Lea and Febiger , 1966, 882-7.

8. Breig A, Adverse Mechanical Tension in the Central Nervous System, New York, NY: John Wiley & Sons; 1978: 11-53.

9. DeJarnette MB, Cranial Technique, self published, Nebraska City, Nebraska, 1975, 21-37, 106-7, 181-2.

10. Upledger JE, Craniosacral Therapy II: Beyond the Dura, Seattle, Washington, Eastland Press, 1987, 115-30.

11. DeJarnette MB, Cranial Technique, self-published, Nebraska City, Nebraska, 1976, 50-2, 105, 200-13.

12. DeJarnette MB, Cranial Technique, self-published, Nebraska City, Nebraska, 1979-1980, 1, 8, 41-2, 81-93, 156-9.

13. Upledger JE, Vredevoogd, JD, Craniosacral Therapy, Seattle, Washington, Eastland Press, 1983:77-87.

14. DeJarnette MB, Sacro Occipital Technique, self-published, Nebraska City, Nebraska, 1984 , 2-7, 46-50, 92-100.

15. Magoun HL, Osteopathy in the Cranial Field, 3rd Edition, Meridian, Idaho: Sutherland Cranial Teaching Foundation; 1976: 1-72.

16. Walther DS, Applied Kinesiology, Vol. II, The Stomatognathic System , Pueblo, CO: Systems DC; 1983: 9-88.

17. Shinomiya K, Dawson J, Spengler DM, Konrad P, Blumenkopf B, An analysis of the posterior epidural ligament role on the cervical spinal cord. Spine , Sep 1996, 21(18): 2081-2088.

18. Hack GD, Koritzer RT, Robinson WL, Hallgren RC, Greenman PE, Anatomical relation between the rectus capitis posterior minor muscle and the dura mater. Spine , Dec 1995, 20(23): 2484-2486.

19. Mitchell B, Humphreys BK, O'Sullivan E, Attachments of the ligamentum nuchae to cervical posterior spinal dura and the lateral part of the occipital bone, Journal of Manipulative and Physiological Therapeutics , Mar/Apr1998, 21(3).

20. Bashline SD, Bilott JR, Ellis JP, Meningovertebral ligaments and their putative significance in low back pain, Journal of Manipulative and Physiological Therapeutics Nov-Dec 1996, 19(9): 592-6.

Correspondence:
Charles L. Blum, DC
1752 Ocean Park Boulevard
Santa Monica, California 90405
(310) 392-9795
Email: drcblum@aol.com