ABSTRACT
Objective@#To observe the root and root canal morphology of mandibular second molars in Western Guangxi by CBCT, to provide a reference for clinical diagnosis and treatment.@*Methods@#In total, 564 patients′ 1 128 mandibular second molars that satisfy the inclusion criteria were analyzed with a planmecaromexis CBCT machine and its own image analysis software. The patients′ gender, age and ethnic differences in the root and canal morphology and the symmetry of the bilateral root and canal were statistically analyzed. @*Results@# Among the 1 128 mandibular second molars, 662 were the Zhuang ethnic group and 384 were the Han ethnic group, and 82 were other ethnic groups; the double root type and C-shaped root type accounted for a relatively high proportion: 73.94% and 24.47%, respectively. The detection rates of the double root type were higher in males than in females (P < 0.05); the detection rates of the C-shaped root type were higher in females than in males (P <0.05); the root type of the teeth was mainly double-rooted in the Zhuang ethnic group (P<0.01). The incidence of type IV in the mesial root of the double root type mandibular second molar was the highest (P < 0.01), and the incidence of type I in the distal root was the highest (P < 0.01). The C-shaped root canal is more continuous at the mouth of the root canal, more downward corresponds to a worse continuity: in three different levels of root canal orifice, root middle and root apex, the root canal orifice is dominated by the C1 type, and both root middle and root apex are mainly C3-type (P < 0.01). The difference in symmetry of bilateral roots and root canals was statistically significant among different gender groups, age groups, and ethnic groups (P < 0.05): there were more males than females, the results in the 18-35-year-old group and the Zhuang ethnic group were higher.@*Conclusion@# The root and root canal morphology of mandibular second molars in western Guangxi people are complex and changeable. The roots are mainly double root type in the Han ethnic group and the Zhuang ethnic group. C-shaped roots are also common. The detection rate of C-shaped roots in the Zhuang ethnic group was higher, and the symmetry rate of bilateral roots and that of bilateral root canals was higher in the Zhuang ethnic group than in the Han ethnic group.
ABSTRACT
Objective To understand and evaluate the prevalence of myopia and its trend in children and adolescents aged 7-18 years in Han ethnic group in China from 2005 to 2014,and provide evidence for the prevention of myopia.Methods The data of 2005,2010 and 2014 Chinese National Students Constitution and Health Surveys were collected.The children and adolescents with complete detection data of binoculus were selected as study subjects.The sample size of three studies were 233 108,215 319 and 212 743,respectively.The method of curve fitting was used to simulate the myopia detection increase model and analyze the gender and area specific myopia detection increase trends and characteristics from 2005 to 2014.Results The overall myopia detection rate increased gradually in the children and adolescents aged 7 to 18,which was 47.5％ in 2005,55.5％ in 2010 and 57.1％ in 2014,respectively.The increase slowed in 2014.A "parabola" shape of myopia detection increase rate was observed.Myopia detection rate increased with age before puberty and decreased with age after puberty gradually.A "cross phenomenon" of myopia detection increase was observed in boys and girls between urban and rural areas.The increase of myopia detection was mainly in urban students before puberty and in rural students after puberty.The age of myopia prevalence peak has become earlier constantly in children and adolescents aged 7-18 years from 2005 to 2014,which was 13 years old in 2005,12 years old in 2010 and 11 years old in 2014.The increase rate was about 7％.During 2005-2014,the increase rate of myopia detection gradually increased in younger students and tended to zero in older students.Conclusion The detection rate of myopia was still high in children and adolescents in China.The age of myopia prevalence peak has become earlier gradually.
ABSTRACT
Objective To understand and evaluate the prevalence of myopia and its trend in children and adolescents aged 7-18 years in Han ethnic group in China from 2005 to 2014,and provide evidence for the prevention of myopia.Methods The data of 2005,2010 and 2014 Chinese National Students Constitution and Health Surveys were collected.The children and adolescents with complete detection data of binoculus were selected as study subjects.The sample size of three studies were 233 108,215 319 and 212 743,respectively.The method of curve fitting was used to simulate the myopia detection increase model and analyze the gender and area specific myopia detection increase trends and characteristics from 2005 to 2014.Results The overall myopia detection rate increased gradually in the children and adolescents aged 7 to 18,which was 47.5％ in 2005,55.5％ in 2010 and 57.1％ in 2014,respectively.The increase slowed in 2014.A "parabola" shape of myopia detection increase rate was observed.Myopia detection rate increased with age before puberty and decreased with age after puberty gradually.A "cross phenomenon" of myopia detection increase was observed in boys and girls between urban and rural areas.The increase of myopia detection was mainly in urban students before puberty and in rural students after puberty.The age of myopia prevalence peak has become earlier constantly in children and adolescents aged 7-18 years from 2005 to 2014,which was 13 years old in 2005,12 years old in 2010 and 11 years old in 2014.The increase rate was about 7％.During 2005-2014,the increase rate of myopia detection gradually increased in younger students and tended to zero in older students.Conclusion The detection rate of myopia was still high in children and adolescents in China.The age of myopia prevalence peak has become earlier gradually.
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Objective: To identify the differential expression of human leukocyte antigen I (HLA-I) between patients of Uighur and Han ethnic groups with cervical diseases. Methods: The expression levels of HLA-I protein in chronic cervicitis, cervical intraepithelial neoplasia (CIN) and cervical squamous cell carcinoma (CSCC) tissues from female patients of Uighur and Han ethnic groups were examined by immunohistochemistry method. Results: The expressions of HLA-I protein in chronic cervicitis, CIN and CSCC tissues were normal, partial-lost and negative, respectively. The total loss rates of HLA-I protein expression were 2% (1/49), 26% (29/113) and 49% (34/70) in chronic cervicitis, CIN and CSCC tissues, respectively (P<0.05). The increasing tendency of total loss rate of HLA-I protein expression accompanied by the enhancement of cervical disease severity in the Uighur ethnic group was similar to that of the Han ethnic group. The total loss rates of HLA-I protein expression in CIN and CSCC tissues were both higher in Uighur women (27% and 53%, respectively) than those in Han women (18% and 37%, respectively). Conclusion: The loss of HLA-I protein expression may predict the progression of cervical cancer. The differential expression of HLA I between Uighur and Han ethnic groups may reflect the different genetic pathways of carcinogenesis.