Orthodontic treatment is more complicated when both soft and hard tissues must be considered because an impacted maxillary canine has important effects on function and esthetics. Compared with extraction of impacted maxillary canines, exposure followed by orthodontic traction can improve esthetics and better protect the patient's teeth and alveolar bone. Therefore, in order to achieve desirable tooth movement with minimal unexpected complications, a precise diagnosis is indispensable to establish an effective and efficient force system. In this report, we describe the case of a 31-year-old patient who had a labio-palatal horizontally impacted maxillary left canine with a severe occlusal alveolar bone defect and a missing maxillary left first premolar. Herein, with the aid of three-dimensional imaging, sequential traction was performed with a three-directional force device that finally achieved acceptable occlusion by bringing the horizontally impacted maxillary left canine into alignment. The maxillary left canine had normal gingival contours and was surrounded by a substantial amount of regenerated alveolar bone. The 1-year follow-up stability assessment demonstrated that the esthetic and functional outcomes were successful.

Objective:To investigate the effect of treadmill training on spasticity and the expression of potassium chloride co-transporter 2 (KCC2) after blocking BDNF-TrkB signaling pathway in rats with incomplete spinal cord injury (SCI).Methods:Forty female Sprague-Dawley rats were randomly divided into a sham-operation group (Sham group), an SCI+ phosphate-buffered saline group (SCI/PBS group), an SCI-treadmill training+ PBS group (SCI-TT/PBS group), an SCI/TrkB-IgG group and an SCI-TT/TrkB-IgG group. All of the rats underwent 1 week of intrathecal catheterization, and then T 10 incomplete SCI was induced. In the Sham group the spinal cord was only exposed. Seven days later, BDNF-TrkB signaling was blocked in the SCI/TrkB-IgG and SCI-TT/TrkB-IgG groups using the TrkB-IgG. The remaining three groups were controls treated with PBS. The SCI-TT/PBS and SCI-TT/TrkB-IgG groups began exercising 7 days after the SCI and continued for 4 weeks. The spasticity in their hind limbs was assessed using the Asworth assessment and H reflex (H-max/M-max ratio). The expression of KCC2 in the distal spinal cord was detected using western blotting and immunohistochemistry. Results:After the SCI the average Ashworth spasticity grades of the four SCI groups increased significantly compared with the Sham group. The average Ashworth spasticity grade of the SCI-TT/PBS group was significantly lower than those of the SCI/PBS and SCI/TrkB-IgG groups in the 3rd through the 5th week, and the SCI-TT/PBS group′s average grade was significantly less than that of the SCI-TT/TrkB-IgG group after 4 weeks. Within 5 weeks the average H-max/M-max ratio of the Sham group remained unchanged, significantly lower than the other 4 groups′ averages. There was no significant difference in the H-max/M-max ratio among the 4 groups of injured rats within 2 weeks after the SCI, but after 3-5 weeks the average H-max/M-max ratio of the SCI-TT/PBS group was significantly lower than those of the SCI/PBS, SCI/TrkB-IgG and SCI-TT/TrkB-IgG groups. At the 4th and 5th week the average H-max/M-max ratio in the SCI-TT/TrkB-IgG group was significantly lower than that in the SCITrkB-IgG group. And after 5 weeks the average expression of KCC2 in the anterior horn of the injured spinal cord was significantly lower in the 4 SCI groups than in the Sham group. Exercise significantly increased the expression of KCC2 in the SCI-TT/PBS group, and its immune intensity and relative optical density were significantly higher than those in the SCI/PBS, SCI/TrkB-IgG and SCI-TT/TrkB-IgG groups. However, there was no significant difference between the SCI/TrkB-IgG group and the SCI-TT/TrkB-IgG group.Conclusions:Treadmill training can improve spasticity after incomplete SCI and the expression of KCC2 in the distal spinal cord, at least in rats.

Objective: To  investigate  the  effect  of  X-ray  on  the  polarization  of  mouse  microglia  BV-2  cells. Methods: BV-2 cells at the logarithmic growth stage were randomly divided into the Sham irradiation group and 10 Gy irradiation group. The latter group was given a single X-ray irradiation at a dose of 1.28 Gy/min for 7 min 49 s. The activation rate of BV-2 cells was observed and analyzed under a microscope at 1, 3, 6, 24 h and 48 h after irradiation.The changes of cell morphology were observed by HE staining and immunofluorescence staining; The levels of M1-type activation markers (TNF-α and IL-1β) and M2-type activation marker TGF-β1 in the supernatant of BV-2 cells were detected by ELISA. The levels of polarization-related proteins of M1-type (CD86 and iNOS) and M2-type (CD206) in BV-2 cells were detected by Western blotting. Results　: Morphological results showed that BV-2 cells became larger, and their protrude became coarse and shorter, showing "amoeba" like changes after 10 Gy X-ray irradiation. Compared with the Sham group, the activation rate of BV-2 cells was significantly increased at 3 h, and reached the peak at 6 h, and began to recover at 48 h after irradiation. ELISA results showed an obvious increase in the level of TNF-α and TGF-β1 48 h after irradiation.The level of IL-1β showed a transient decrease at 3～6 h, increased at 24 h, and reached the peak 48 h after irradiation. Western blotting results showed that CD86 protein level did not change significantly at each time points after irradiation, and iNOS protein level in- creased significantly at 1, 6, 24 h and 48 h after irradiation. A fluctuating change in CD206 protein level was found after irradiation. Conclusion　 10 Gy X-ray irradiation can induce the activation of BV-2 cells in vitro, and the polarization type changes with the time after irradiation.