Nickel titanium alloy is a binary alloy composed of nickel ions and titanium ions. Due to the change of temperature and mechanical pressure, there are two different crystal structure phases, namely Austenite phase (Austenite phase) and Martensite phase (Martensite phase). The phase transition sequence of Ni-Ti alloy is parent phase (austenite phase) -R phase - martensite phase. The R phase is rhomboid, the austenite is the state when the temperature is high (greater than likewise: the temperature at which the austenite begins), or when the load is removed (Deactivation of external forces), the cube, and the hard state. The shape is relatively stable. The martensite phase is a state at a relatively low temperature (less than MF: the temperature at which martensite ends) or when it is loaded (activated by external forces). It is hexagonal, ductile, repetitive, unstable and easy to deform. Therefore, the determination of phase transition temperature of Nitinol alloy arch wire has positive guiding significance in clinic so that clinicians can make better use of the properties of Nitinol alloy for clinical orthodontic treatment.
The two ends of the memory titanium alloy plate distractor are fixed feet, a titanium nickel memory alloy distractor. In the middle is the afterforce section, bent into an S or C shape, or bent into a Z or multiple Z shape. Titanium plate memory alloy distractor has the advantages of small size, shape memory function, automatic force, can be completely buried in the body, not easy to infect, easy to use and comfortable. The distractor is made of titanium plate shape memory alloy wire. During the operation, osteotomy was performed first to form a distraction bone block, then holes were punched on both sides of the osteotomy space, and a distractor was inserted after cooling and compression deformation. After suturing the wound, the distractor was completely embedded. At human temperature, the distractor automatically opens and expands the bone gap, and new bone is formed in the resulting gap, thereby lengthening or broadening the bone.
Congenital scoliosis in children is still a difficult problem in the world medical field, and its etiology is not clear at present. This disease affects the growth and development of children, making the appearance of serious deformity after adults. Radical orthopedic surgery in the correction of scoliosis at the same time, but also affect the growth and development of children, mainly the upper body can no longer grow and develop, the problem of short upper body. Moreover, the crankshaft and the titanium plate used for internal fixation are easy to come out and need to be repaired by another operation. With congenital scoliosis, 6-year-old Tan Jun this year left and right shoulder tilt, scapula kyphosis, spinal deformation, spinal canal also long a 6 cm long tumor. In early March this year, Tan Jun was sent to the University of South China attached to a hospital treatment, the hospital spinal surgery professor Wang Wenjun using the new children's growth rod orthopedic technology, for Tan Jun to complete the orthopedic, fixed, but also the use of microscopic technology to remove the child's spinal canal tumor. Tan Jun was hospitalized for more than 20 days, recovered and discharged from hospital and will be able to grow normally in the future.
