Résumé
Objective@# To study the buccolingual inclination of posterior premolars and molars and the curve of Wilson in patients with different sagittal skeletal patterns, to explore the compensation mechanism of horizontal inclination of posterior teeth in patients with different sagittal skeletal patterns and to provide a reference for the control of posterior tooth inclination in the treatment of bone malocclusion.@*Methods@#This study was reviewed and approved by the Ethics Committee, and informed consent was obtained from the patients. Ninety CBCT scans of adults and ninety scans of adolescents before orthodontic treatment were evaluated in this cross-sectional study. There were 30 skeletal Class I, Class Ⅱ, and Class Ⅲ patients in the adult group and adolescent group. The inclination angles of posterior teeth and the curve of Wilson of first and second molars were measured, and data were analyzed between adolescents and adults with different sagittal skeletal patterns.@*Results @#Compared with skeletal Class Ⅰ adult patients, the upper posterior molar inclination of skeletal Class Ⅱ patients was significantly lower, and the lower posterior molar inclination was significantly higher. Compared with skeletal ClassⅠ adult patients, the upper posterior molar inclination of skeletal Class Ⅲ adult patients was higher, and the lower posterior molar inclination was significantly lower. The Wilson curve of the second molar in skeletal Class Ⅱ adult patients was significantly higher than that in the other groups. Compared with skeletal ClassⅠ adolescent patients, skeletal Class Ⅲ adolescent patients had a significantly higher upper posterior molar inclination; however, no difference was found between the inclination of the posterior teeth between skeletal Class Ⅰ, Class Ⅱ and Class Ⅲ adolescent patients. Comparing adolescent and adult samples, in skeletal Class Ⅱ patients, adults showed more lingual inclination than adolescents in the upper posterior teeth and less lingual inclination in the lower posterior teeth except for the mandibular first molar. Comparing adolescent and adult samples, in skeletal Class Ⅲ patients, adults showed more lingual inclination than adolescents in the lower posterior teeth except for the mandibular second molars and showed no difference in the upper posterior teeth.@*Conclusions@#The inclination of the posterior teeth and the curve of Wilson show significant differences between the three sagittal skeletal patterns. Compared with those of skeletal Class Ⅰ patients, the posterior teeth of skeletal Class Ⅱ patients show more lingual inclination in the upper arch and less lingual inclination in the lower arch. Meanwhile, posterior teeth of skeletal Class Ⅲ patients show more lingual inclination in the lower arch and maintain the inclination in the upper arch.
Résumé
Objective@#To investigate routine blood test results and secular changes among Tibetan children and adolescents aged from 3 to 19 in the plateau, and to provide the basis for reference range of routine blood test for this population.@*Methods@#A total of 1 568 Tibetan children and adolescents aged from 3 to 19 living in Shigatse, Tibet were selected by cluster random sampling method. Routine blood test results and its secular trends were compared by age and gender.@*Results@#Significantly differences were found in red blood cell(RBC), hemoglobin(HGB), hematocrit (HCT), mean corpuscular volume (MCV), mean corpuscular hemoglobin(MCH), white blood cell(WBC), neutrophil(NEU), neutrophil percentage (NEU%), lymphocyte(LYM), lymphocyte percentage(LYM%)，monocyte percentage(MON%)，eosinophil percentage(EOS%),basophil percentage(BAS%) and platelet(PLT) among the four age groups of 3-5, 6-12, 13-15, and 16-19 years ( F/H =60.22, 179.41, 249.45, 115.03, 74.90, 14.33 , 33.46, 78.90, 49.20, 97.29, 24.45,24.28,42.65,20.10, P <0.05). Among red blood cell indexes, RBC, HGB, HCT,MCH increased with age in boys( F =148.77, 493.04, 623.14, 249.92, P <0.05), but there was no similar trend in girls( F =1.37, 0.15, 2.94, 0.11, P >0.05). HCT showed significant sex differences among the four age groups of 3-5 years, 6-12 years, 13-15 years, and 16-19 years [(41.33±2.31)% vs (41.98±2.40)%; (43.28±2.60)% vs ( 43.75 ±2.36)%; (46.20±3.11)% vs (44.83±2.67)%; (51.10±4.15)% vs (43.61±4.70)%, t =-2.10, -2.88, 3.50, 10.82, P <0.05]. WBC, NEU, NEU%, LYM, LYM%, monocyte(MON), and MON% increased significantly with age in both boys and girls ( P <0.05). From the age of 12 to 13, RBC, HGB and HCT in Tibetan male and female adolescents showed an opposite trend and widened gradually.@*Conclusion@#Red blood cell index shows significantly different trends among Tibetan adolescents and children of different ages and genders. Regional nationality, age, gender, and other factors should be considered when developing the reference value range of blood routine index.
Résumé
Objective@#To investigate routine blood test results and secular changes among Tibetan children and adolescents aged from 3 to 19 in the plateau, and to provide the basis for reference range of routine blood test for this population.@*Methods@#A total of 1 568 Tibetan children and adolescents aged from 3 to 19 living in Shigatse, Tibet were selected by cluster random sampling method. Routine blood test results and its secular trends were compared by age and gender.@*Results@#Significantly differences were found in red blood cell(RBC), hemoglobin(HGB), hematocrit (HCT), mean corpuscular volume (MCV), mean corpuscular hemoglobin(MCH), white blood cell(WBC), neutrophil(NEU), neutrophil percentage (NEU%), lymphocyte(LYM), lymphocyte percentage(LYM%)，monocyte percentage(MON%)，eosinophil percentage(EOS%),basophil percentage(BAS%) and platelet(PLT) among the four age groups of 3-5, 6-12, 13-15, and 16-19 years ( F/H =60.22, 179.41, 249.45, 115.03, 74.90, 14.33 , 33.46, 78.90, 49.20, 97.29, 24.45,24.28,42.65,20.10, P <0.05). Among red blood cell indexes, RBC, HGB, HCT,MCH increased with age in boys( F =148.77, 493.04, 623.14, 249.92, P <0.05), but there was no similar trend in girls( F =1.37, 0.15, 2.94, 0.11, P >0.05). HCT showed significant sex differences among the four age groups of 3-5 years, 6-12 years, 13-15 years, and 16-19 years [(41.33±2.31)% vs (41.98±2.40)%; (43.28±2.60)% vs ( 43.75 ±2.36)%; (46.20±3.11)% vs (44.83±2.67)%; (51.10±4.15)% vs (43.61±4.70)%, t =-2.10, -2.88, 3.50, 10.82, P <0.05]. WBC, NEU, NEU%, LYM, LYM%, monocyte(MON), and MON% increased significantly with age in both boys and girls ( P <0.05). From the age of 12 to 13, RBC, HGB and HCT in Tibetan male and female adolescents showed an opposite trend and widened gradually.@*Conclusion@#Red blood cell index shows significantly different trends among Tibetan adolescents and children of different ages and genders. Regional nationality, age, gender, and other factors should be considered when developing the reference value range of blood routine index.