Among all seven cervical vertebrae, the first cervical vertebra is called the cervical spine and the second cervical vertebra is called the pivot vertebrae. The cervical vertebrae have no vertebral body or spinous process, but have an anterior arch, a posterior arch and two lateral blocks, and are named because of their annular shape. The pivotal vertebrae have a special morphology of a bony projection on the vertebral body called the dentate process or dentate process. There are four separate joints in the crico-pivotal joint, with the lower articular surface of the crico-vertebrae and the upper articular surface of the pivot vertebrae forming the left and right two crico-pivotal lateral joints; the anterior articular surface of the dentate process of the pivot vertebrae and the articular surface of the dentate process of the crico-vertebrae forming the crico-pivotal anterior joint; and the articular surface of the dentate posterior joint and the transverse ligament of the crico-vertebrae forming the crico-pivotal posterior joint. Their joint capsules are loose and thin, especially the posterior posterior ligament of the cricetabular spine, which has only its anterior middle fibrocartilage forming the articular surface, so it is more prone to a mild misplacement of each other. Of the four parts of the crico-pivotal joint, there is only one vertical axis of motion through the tip of the odontoid process, and the crico-spine rotates along both sides of this axis through the crico-occipital joint together with the head. In addition, a slight forward-posterior and lateral movement may occur between the cervical spine and the pivotal spine. I. Etiology When the neck activity exceeds the normal range, or uncoordinated activities, can make the tooth process of the pivot vertebrae located in the abnormal position in the circumflex vertebrae, the two circumflex lateral joints are also in the corresponding displacement, this involves the misplacement of the four parts of the circumflex joint, called the circumflex misalignment suture. The direction of the slight misalignment can be forward, backward, left, right and rotation, and it is generally difficult to distinguish the specific misalignment direction clinically, but a reset method can be used to correct the slight misalignment between the various articular surfaces at the same time. Diagnosis and Differentiation (a) History of neck sprain, pillow, wind chill or long-term work of twisting and stretching and rotating shoulder, as well as occasional activities of special direction of the neck (such as dancing in Xinjiang, moving the neck to the side). (B) Pain in the occipital area behind the head, often radiating to the scalp at the back of the head. (c) Muscle spasm in the neck, especially at the upper cervical end, can often be felt on both sides of the circumflex and pivot vertebrae with tendon knots and tendon rope-like changes, and the pressure pain is also at these soft tissue abnormal changes. (d) The neck rotation does not reach the normal range of 30 degrees on each side, and is accompanied by pain and uncomfortable feeling. (v) Some patients have symptoms of internal facial pain and injury such as headache, sore throat, tinnitus and vertigo. (f) Open mouth radiographs may sometimes show changes in the cricoarticular misalignment suture, mainly a shift of the dentition axis to the side of the cricoarticular axis, as well as non-parallelism between the cricoarticular lateral articular surfaces and unequal width of the left and right lateral articular gaps. The specific measurement method is: make the line of the outermost edge of the lower articular process on both sides of the annulus vertebrae, and the annular base line, and make a vertical line called the annulus vertebrae axis at the end of the annular base line, when normal, the axis of the odontoid process should overlap with the axis of the annulus vertebrae, if the two axes are separated, the side from which the odontoid process axis has moved out is the direction of the wrong bone suture; the distance between the left and right lateral articular surfaces should be equal, and the articular surfaces on the same side should be parallel to each other, if the gap between the articular surfaces on both sides is not equal, and the adjacent to If the joint surface gap between the two sides is not equal and the adjacent surfaces are not parallel, then it is a misaligned suture. Because of the minimal degree of disorder in some circumferential misaligned joints, there are often obvious symptoms and signs, but the situation cannot be shown on X-ray. In addition, rotational displacement is more difficult to show on open mouth orthopantomogram and lateral radiographs. Therefore, X-ray examination is important for the diagnosis of crico-axial subluxation, but is only of diagnostic value for misaligned sutures that are more mild than subluxation.