Objective To investigate the clinical significance of preoperative three-dimensional CT scan parameters to restore postoperative limb length and reduce postoperative dislocation in patients with total hip arthroplasty (THA).Methods Clinical data of two groups involving 86 cases that had primary unilateral THA were included.In study group 45 cases were operated on with the measurement of contralateral acetabular anteversion, acetabular abduction angle, distance from femoral neck osteotomy to the center of rotation of the femoral head and distance from femoral trochanter tip to the center of rotation based on three-dimensional CT scan.Another 41 cases under conventional surgery which not used these parameters served as control.Surgical efficacy was compared to verify the role of CT scan parameters in restoring postoperative limb length and reducing postoperative dislocation.Results Period of follow-up was (11.2 ± 6.2) months in study group and (11.6 ± 6.2) months in control group.Harris hip score in study group was (87.2 ± 5.4) points versus (80.9 ± 7.9) points in control group three months after operation (P ＜ 0.05).Limb length discrepancy in study group was (0.4 ± 0.2) cm versus (1.1 ± 0.4) cm in control group (P ＜ 0.05).Each group had one dislocation three months after operation.Conclusion The parameter measurement with three-dimensional CT scan has some guiding significance in THA.

Objective To explore the effect of duraphat varnish on reducing orthodontic tooth enamel demineralization around brackets.Methods We Selected 30 patients aged 12 to 14 years old in orthodontic Departrnent of Shenyang Stomatological Hospital from Jan 2011 to Dec 2013 and carried out rectification scheme to pull out the first premolar after test.The full mouth dental were divided into four parts by the quadrant and the first premolars of different groups were coated with Tooth Mousse,Fluor Protector and saline (as control group),duraphat varnish (as experimental group) respectively.Every group included 30 teeth.Three months later,We observed the demineralization of the teeth.The enamel decalcification of all quarters were detected by DI-AGNOdent.Results The rate of enamel demineralization in the experimental group was 10.0％,that in the Tooth Mousse group was 13.3％,the 0.1％ Fluor Protector group 23.3％,the saline group 53.3％.There were significant statistical difference of the rate of enamel demineralization between the Duraphat varnish group and 0.1％ Fluor Protector group,and that between the Duraphat varnish group and the saline group (P ＜ 0.01).There was no statistical difference of that between the Duraphat varnish group and the Tooth Mousse group (P ＞0.05).There were no statistical difference of DIAGNOdent reading between the experimental group and the control groups before bonding(P ＞ 0.05).After bonding,one month later and three months later,there was no statistical difference of DIAGNOdent reading between the Duraphat varnish group and the Tooth Mousse group (P ＞ 0.05).There was significant statistical difference of that between the Duraphat varnish group and 0.1％ Fluor Protector group(P ＜ 0.01).Conclusion Duraphat varnish can reduce the tooth enamel demineralization more effectively than 0.1％ Fluor Protector and saline in orthodontic treatment,and also can be used for children who were wearing fixed orthodontic appliances.

Objective To investigate nasomaxlllary complex facial soft tissue changes after the treatment with maxillary protraction appliance with skeletal Class Ⅲ malocclusion with a retruded maxilla.Methods Thirty growing subjects with skeletal Class Ⅲ malocclusions with maxillary retrognathism were selected and treated by facial mask(male 15,female 15,with an average age of 10.5).They were given a maxillary protraction treatment with face mask for 6-8 months.Cephalometric measurements about nasomaxillary complex soft tissue changes were analyzed to draw the statistic conclusion.Results After maxillary protraction treatment,PraY,nasofrontal angle,As-Y,UL-Y,UL-E,S-Ns-Sn increased (P ＜ 0.01) ; M-Y increased (P ＜ 0.05) ; LL-E,PosY,nasolabial angle decreased (P ＜ 0.05).There were no significant differences in the Ns-Y and columella-tip angle.Conclusion After maxillary protraction treatment,nasomaxillary complex area becomes more marked.Both the nasomaxillary complex soft tissue and lower facial profile are dramatically improved.The combining effect of these two changes results in a more harmony profile.

Objective: To analyze the trend and characteristics of school tuberculosis epidemic in Shijiazhuang from 2011 to 2020, and to provide reference for school tuberculosis prevention and control. Methods: Descriptive methods were used to analyze the epidemiological characteristics of tuberculosis among students and the epidemic situation of tuberculosis in schools in Shijiazhuang from 2011 to 2020. The χ 2 test and χ 2 trend test were used to analyze the characteristics and trend of school tuberculosis. Results: A total of 4 896 cases of tuberculosis were registered among students in Shijiazhuang from 2011 to 2020. The average annual registered incidence rate of students was 24.69/100 000, and the difference in incidence rate was statistically significant ( χ 2=318.50, P <0.01) the overall registered incidence rate of tuberculosis among students in the past 10 years was on the rise ( χ 2 trend =87.79, P <0.01). Among the student cases, male accounted for 53.89%, female accounted for 46.11%. The age group of students aged >18 and above accounted for the largest proportion(50.35%), followed by the age group aged 16-18( 35.80 %). Most students cases occurred in April and September-November, with September the highest(12.03%). A total of 22 clustered outbreaks (174 cases) and the aggregate epidemic accounted for 3.55% of the total number of students with tuberculosis. Conclusion The prevention and control of tuberculosis epidemic in schools in Shijiazhuang should not be underestimated, and strengthen the supervision, management, publicity and education of students in key age groups to avoid clusters of outbreaks.