Objective To investigate the dynamics and development trends of drinking water type of endemic fluorosis after water improvement in Xinbaerhuyouqi of Hulunbeir city, Inner Mongolia and to provide a scientific evidence for the development of countermeasures. Methods We mainly selected Adunchulusumu and Kerlunsumu in Xinbaerhuyouqi of Hulunbeir city as the two monitoring points after water improvement in 2000 -2009. Of these, 1 sample of centralized water supply source water and 3 samples of tap water and 5 samples of noncentralized water supply source water according to water well locations of east, west, south, north and center were collected and the levels of water fluoride were tested; the prevalence of dental fluorosis of school children aged 8 to 12 were examined; from 2002 onwards, the urine samples of 30 children aged 8 to 12(five age groups, six urine samples for each age group) were collected, and all urine samples were collected in the case of less than 30, and urine fluoride was tested. Dental fluorosis was diagnosed using Dean method; water fluoride was tested using fluoride ion selective electrode(WS/T 106-1999); urinary fluoride was tested by determination of fluoride in urine using ion-selective electrode(WS/T 89-1996). Results In 2000 - 2009, the mean levels of fluorine in drinking water in Adunchulusumu and Kerlunsumu were 1.79 - 4.35 mg/L and 1.38 - 3.18 mg/L, respectively; the detection rate of dental fluorosis of children aged 8 to 12 were 45.24％(19/42) - 89.78％(123/137) and 40.00％ (28/70) - 74.47％ (70/94), respectively; the median urinary fluoride of them were 2.30 - 4.15 mg/L and 2.73 - 4.55 mg/L, respectively. ConclusionsThe detection rate of children's dental fluorosis remains high in Xinbaerhuyouqi during the past 10 years after changing water. The endemic fluorosis remains a serious disease. Effective prevention and control measures must be taken to control the occurrence of fluorosis in the future.

Objective To measure and compare the lateral posterior tibial slope (LPTS) , medial posterior tibial slope ( MPTS) and tibial torsion angle ( TTA) between the patients of recuiTent patellar dislocation and the heathy people, and to analyze the correlation between LPTS, MPTS and TTA and the risk factors of recuiTent patellar dislocation. Methods A total of 33 patients (44 knees) with recuiTent patellar dislocation in our hospital from July 2019 to June 2021 were selected and listed as the stud)' group. Twenty-three subjects (46 knees) who were suspected iliac vascular and lower limb vascular diseases during the same period were selected and listed as the control group. All the enrolled researchers had fulllength CT scans date of the lower limbs. Three-dimensional models were reconstructed using Mimics 21. 0 software and then imported into 3-matic software. The LPTS, MPTS and TTA were measured and compared between the two groups. Results In the study group, the LPTS, MPTS and TTA were (7. 69} 1. 42) ° , ( 10. 06} 1. 71) ° , ( 36. 42}8. 13 ) ° , respectively while the control group, the LPTS, MPTS and TTA were ( 8. 42 } 1. 65 ) ° , ( 10. 44 } 0. 86 ) ° , ( 25. 77} 3. 90 ) ° , respectively. There were no signiiicant differences in the LPTS, MPTS and TTA between different genders and sides both in the stud)' group and the control group ( P > 0. 0 5 ) . Compared with the control group, the LPTS in the stud)' group was smaller, and the difference was statistically significant (P<0. 0 5 ) . There was no statistically significant difference between the stud)' group and the control group in the MPTS (P>0. 05). Compared with the control group, the TTA in the stud)' group was higher, and the difference was statistically significant (P< 0. 0 5 ) . Compared with the control group, the LPTS and MPTS in the study group were significant asymmetry, and the difference was statistically significant ( P < 0 . 0 5 ). Conclusion The lateral posterior tibial slope of patients with recurrent patellar dislocation is significantly smaller than that in the healthy people, while there is no significant difference in the medial posterior tibial slope; The tibial torsion angle of patients with recurrent patellar dislocation is significantly larger than in the healthy people; The lateral posterior tibial slope and tibial torsion angle have certain correlation with recurrent patellar dislocation, which can conduct the diagnosis of recurrent patellar dislocation.