动物造模 z-bo 2022-02-19 350

　　The animal experiment study of orthognathic surgery and temporomandibular joint is to simulate various orthognathic operations on the human body on an animal model, and observe the postoperative morphological and functional changes of the temporomandibular joint. It is to study the influence of orthognathic surgery on the temporomandibular joint. Important means. Wang Hao and others established a bilateral vertical osteotomy of ascending mandibular branches using miniature pigs.

　　1. Experimental method Four 12-month-old Chinese experimental mini-pigs weighing 35-40 kg were selected for the experiment. They were randomly divided into four groups. The first group moved the condyle 6mm forward, the second group moved the condyle 3mm forward, the third group moved the condyle 3mm back, and the fourth group was a blank control group. After conventional anesthesia of miniature pigs, take the lateral position, shave, sterilize, and drape, make an incision on the left submandibular edge, and go straight to the bone surface, and use a periosteal separator to separate the subperiosteal up along the bone surface to the zygomatic sigmoid notch Place. In the forward movement group, a split drill was used to make two vertical osteotomy marking lines from the sigmoid notch to the lower edge of the mandible on the outside of the ascending branch. The distance was equivalent to the amount of advancement. The split drill was completely ground along the two vertical osteotomy lines. Ascending mandibular branch. The proximal and distal bone segments were ligated and fixed with double strands of stainless steel wire<0.3mm. If you need to move the condyle back, make a vertical osteotomy line from the sigmoid notch down to the middle part of the ascending branch, and then make a horizontal bone incision to the posterior edge of the mandible to separate the mesial and distal bones. A full-thickness bone piece with a width of 3mm was cut from the lower half of the posterior edge of the mandible and implanted in the vertical bone incision of the mesiodistal bone segment, so that the condyle bone segment was moved back 3mm. After completion of osteotomy and steel wire ligation, the surgical area was washed with normal saline, and the periosteum, muscle layer, subcutaneous and skin layers were sutured in layers. The same surgical method is used to complete the contralateral vertical osteotomy.

　　Using the Prospeed Ⅱ full-body scanner from GE, the miniature pig is in the supine position during scanning. The pig’s head and spine are at 900 angles, centered on the temporomandibular joint, with a layer thickness of 1mm, and spiral scanning without layer spacing, starting from the cervical vertebra 1 to 2 It ends at the junction of the front third of the mandible. After the scan is completed, a two-dimensional tomographic reconstruction is performed, and a curved sagittal reconstruction is used to show the joint conditions more fully and well. First select the well-displayed joint level as the reference for tomography; then draw the tomographic curve, passing through the joint and ascending branch bone center to ensure the best sagittal joint tomography; finally save the best image and take a photo with a laser camera The preparations were compared before operation, immediately after operation, 1 week after operation, 4 weeks after operation, and 16 weeks after operation to observe the changes of the temporomandibular joint space on both sides.

　　2. Experimental results Three pigs grew well after the operation, and the wounds healed by first intention. In the case of feeding the same food, compared with the control group, 3 pigs had no abnormal chewing movement during the postoperative eating process.

　　When the specimen was cut 1 week after the operation, the bone stump had not healed after the bilateral ascending mandibular vertical osteotomy. Fibrous connective tissue can be seen at the bone stump, and the steel wire ligated to the bilateral ascending mandibular ramus is firm without loosening. The surface of the infratemporal depression, condyle, and articular discs of the left and right temporomandibular joints are smooth, without defects or deformation.

　　When the specimens were taken 4 weeks after the operation, the gastric stump healed at first stage after the bilateral ascending mandibular vertical osteotomy. The steel wires ligated to the ascending mandibular ramus on both sides were firm, and no loosening was seen. The surface of the infratemporal depression, condyle, and articular discs of the left and right temporomandibular joints were smooth, without defects or deformation.

　　When the specimen was cut 16 weeks after the operation, it was found that the bone ends after the vertical osteotomy of the bilateral ascending mandibular branches healed at first stage. The steel wire ligated to the bilateral ascending mandibular ramus is covered by healed cortex, and the outer bone surface of the ascending ramus is smooth; the surface of the infratemporal depression, condyle, and articular discs of the left and right temporomandibular joints are smooth, without defects or deformation.

　　When the condyles are moved forward by 6mm, the anterior and posterior spaces of the temporomandibular joint on both sides increase, and the bilateral condyles move downward and shift forward. When the condyle was moved forward by 3mm, the anterior space of the bilateral temporomandibular joint was reduced, the posterior space was enlarged, and the bilateral condyle shifted forward. When the condyle was moved back 3mm, the anterior space of the temporomandibular joint increased, the posterior space decreased, and the bilateral condyles shifted back. The blank control group was compared with the first group, the second group, and the third group before operation, 1 week after operation, 4 weeks after operation, and 16 weeks after operation. There was no significant change in the temporomandibular joint space on both sides.