A three-dimensional finite element model of the maxillary canine was developed including periodontal ligament, pulp and alveolar bone. And the stress distributions in the periodontal tissue were obtained under different orthodontic force. The specific aims were to make the model by means of the more advanced and accurate twin CT, to provide more accurate data for clinical use, and to build a more accurate model for the simulation of maxillary canine movement under orthodontic forces.
Cuspid ; Dental Stress Analysis ; Finite Element Analysis ; Humans ; Maxilla ; Models, Biological ; Orthodontic Appliances ; Periodontal Ligament ; physiopathology ; Periodontium ; physiopathology ; Stress, Mechanical ; Tooth Movement Techniques

Objective To investigate the effects of lipoxin A4 on store-operated calcium channel (SOC) and production of reactive oxygen species in macrophages induced by hpopolysaccharide (LPS).Method Macrophages were randomly assigned Io one of the following six groups:control group,LPS group,Thapsigargin group,lipoxin A4+LPS group,lipoxin A4+Thapsigargin group,2-Aminoethoxydiphenylborate+Thapsigargin group.The intracellular[Ca2+]iwas analyzed by eonfoeal laser microscopy.The production of reactive oxygen specips(ROS) was assayed by flow cytometry.Results LPS increased intracellular[Ca2+]i and reactive oxygen species in a dose-dependent manner.Lipoxin A4 suppressed approximately 75% of the Ca2+ ertry signal induced by thapsigargin and suppressed approximately 93% of the Ca2+ entry signal induced by LPS.The increase in intracellular[Ca2+]i was associated with increased ROS production which was abolished in the presence of lipoxin A4.Conclusions These findings indicate that the LPS-indueed intracellular[Ca2*]i increase depends on the Ca2+entry through SOC channel,and lipoxin A4 inhibits Ca2+ influx and ROS production through SOC channel in ratine maerophages induced by LPS.

Objective To observe the clinical efficacy of silver ion antimicrobial dressing for elderly patients with lower extremity ulcer. Methods 52 senile venous lower extremity ulcer patients were randomly divided into control group and observation group, with 26 cases in each group. The control group was treated with traditional 5％ iodine disinfection and dressing with gauze. The observation group was treated with silver ion antibacterial dressing stuffing wound dressing after 5％ iodine disinfection. The wound area, depth, exudation, pain score and nursing satisfaction between the two groups were compared. Results The wound area and the depth of wound in the observation group decreased significantly from the first week, and the difference between the observation group and the control group was statistically significant(P＜0. 01 ). From the fourth week, the exudate volume in the observation group was significantly lower than that of the control group, and the pain scores in the observation group were significantly lower than those in the control group, and the difference was statistically significant (all P＜0. 0l). The effective rate and the cure rate was 46. 2％ and 38. 5％ in observation group, significantly higher than that of the control group(30. 5％ and 15. 4％), and the difference was statistically significant(P all ＜0. 05). The satisfaction of patients in observation group and control group was 84. 6％ and 19. 2％, respectively, with significant difference (P＜0. 05). Conclusion Silver ion antimicrobial dressing for the treatment of senile venous lower ulcer has significant anti-infective effect, with high satisfaction of patients, which is worthy of clinical promotion.