Evaluation of Head and Cervical Spine Posture after Therapy with Maxillary Protraction Appliances / Evaluación de la Postura de la Cabeza y la Columna Cervical Después de la Terapia con Aparatos de Protracción Maxilar

SUMMARY: The objective of this study was to evaluate the changes of head and cervical spine posture of skeletal class malocclusion in adolescent with maxillary protraction. Thirty cases of skeletal class malocclusion were randomly selected from the Stomatological Hospital of Shanxi Medical University. High-quality lateral cephalograms were collected including pre- and posttreatment to compare the changes of head and cervical spine posture. Data were processed using SPSS 26.0 statistical software. The paired-t test was used to compare pre- and posttreatment mean angular measurements.A significant difference in the SNA(p<0.001), SNB(p<0.01), and ANB(p<0.001) between T1 and T2 showed an improvement in the sagittal relationships. A significant change was observed in middle cervical spine posture, while upper cervical spine posture variables showed no significant difference after treatment. Skeletal class with maxillary protraction appliance not only led to the improvement of sagittal relationship, but also changed the middle cervical spine posture.

El objetivo de este estudio fue evaluar los cambios en la postura de la cabeza y la columna cervical debido a la maloclusión clase esquelética en adolescentes con protracción maxilar. Treinta casos de maloclusión de clase esquelética fueron seleccionados al azar del Hospital Estomatológico de la Universidad Médica de Shanxi. Se recogieron cefalogramas laterales de alta calidad, incluidos el tratamiento previo y posterior, para comparar los cambios en la postura de la cabeza y la columna cervical. Los datos se procesaron con el software estadístico SPSS 26.0. Se utilizó la prueba t pareada para comparar las medidas angulares medias antes y después del tratamiento. Una diferencia significativa en SNA (p <0,001), SNB (p <0,01) y ANB (p <0,001) entre T1 y T2 mostró una mejora en las relaciones sagitales. Se observó un cambio significativo en la postura de la columna cervical media, mientras que las variables de postura de la columna cervical superior no mostraron diferencias significativas después del tratamiento. La clase esquelética con aparato de protracción maxilar no solo condujo a la mejora de la relación sagital, sino que también cambió la postura de la columna cervical media.

Finite element analysis of tooth movement under different retraction force and intrusive force in double-archwire lingual orthodontics system.

The objectives of this study were to evaluate the tooth movement tendency during space closure in maxillary anterior teeth by various combinations of retraction force and intrusive force in a double-archwire lingual orthodontic system. Mini-implant-double slot lingual orthodontics system models of the bilateral maxillary first premolar extraction cases were constructed. Three-dimensional finite element models of the maxilla were constructed with definite position mini-implants (8 mm) and power arms (6 mm). Different retraction forces(50gf、100gf、150gf)were applied with the help of a nickel-titanium closed coil spring on the plate side. Intrusive forces(0gf、50gf、100gf)were applied with the help of the mini-implant between the two central incisors, and the initial displacements of the maxillary anterior teeth were analyzed. Variable amounts of displacements like controlled tipping, uncontrolled tipping, lingual crown tipping, labial root tipping, extrusion and distal crown tipping were observed in all the models, and these tendencies increased as the magnitude of retraction force increased, and these tendencies decreased as the magnitude of intrusive force increased. When the intrusive force was greater than or equal to the retraction force, the maxillary central incisors showed the trend of lingual crown tipping and labial root tipping, resulting in uncontrolled tipping movement. In terms of horizontal changes, the increasing width of bilateral anterior teeth was observed, with canines showing the least increasing trend. Various combinations of retraction force and intrusive force in a double-archwire lingual orthodontic system provide a new choice for torque control of the anterior teeth. Although anterior mini-implants and elastics can achieve incisor intrusion and lingual root torque, they cannot achieve the expected torque without additional torque control methods.

Exploring lemology teaching with "internet plus" flipped classroom pedagogy.

BACKGROUND: To investigate the use of flipped classroom pedagogy based on "Internet plus" in teaching viral hepatitis in the lemology course during the COVID-19 epidemic. METHODS: This study included students from the clinical medicine general practitioner class at Nanjing Medical University's Kangda College, with the observation group consisting of 67 students from the 2020-2021 school year and the control group consisting of 70 students from the 2019-2020 school year. The observation group used "Internet plus" flipped classroom pedagogy, while the control group used conventional offline instruction. The theory course and case analysis ability scores from the two groups were compared and analyzed, and questionnaire surveys were administered to the observation group. RESULT: After the flipped classroom, the observation group had significantly higher theoretical test scores (38.62 ± 4.52) and case analysis ability scores (21.08 ± 3.58) than the control group (37.37 ± 2.43) (t = 2.024, P = 0.045) and (19.16 ± 1.15) (t = 4.254, P < 0.001), respectively. The questionnaire survey in the observation group revealed that the "Internet plus" flipped classroom pedagogy approach can help enhance students' enthusiasm to learn, clinical thinking ability, practical application ability, and learning efficiency, with satisfaction rates of 81.7%, 85.0%, 83.3%, and 78.8%, respectively; 89.4% of students expressed hope that whenever physical classes resumed, the offline courses could be combined with this pedagogy approach. CONCLUSION: The use of the "Internet plus" flipped classroom pedagogy technique for teaching viral hepatitis in a lemology course boosted students' theory learning ability as well as their case analysis ability. The majority of students were pleased with this type of instruction and hoped that whenever physical classes resumed, the offline courses may be integrated with the "Internet plus" flipped classroom pedagogical approach.

Morphology changes of maxillary molar distalization by clear aligner therapy / Cambios de la morfología en la distalización de molares maxilares mediante terapia con alineadores transparentes

SUMMARY: To evaluate the skeletal, dento-alveolar and soft tissue morphology changes after maxillary molar distalization by clear aligner therapy and identify the significant efficacy of molar distalization,18 patients in conformity with the inclusion criteria were selected. Pre- and post-treatment Cone Beam Computed Tomography (CBCT) were examined to measure the angular and linear parameters. All subjects were completed non-extraction clear aligner treatment by distalizing molars. A paired-t test and independent-samples t-test were performed to observe the difference between before and after treatment and the difference between the first molar and second molar respectively. P-values <0.05 were considered statistically significant. Predicted movement rate was calculated by the formula: (actual movement(mm)/planned movement(mm)) x100%. Most variables of pre- and post-treatment showed no statistical difference(P<0.05), excepting SNA angle (P<0.05) and Upper lip/E-line linear (P<0.01) due to incisor retraction. The first and second molar revealed a translation movement without significant tipping and vertical movement. Clear aligners provided a high predictability (83.44 %) of distalization the maxillary first molar, and 85.14 % of the maxillary second molar. Clear aligners can effectively achieve distal displacement of molars.

RESUMEN: Se seleccionaron 18 pacientes, de acuerdo con los criterios de inclusión, para evaluar los cambios en la morfología esquelética, dentoalveolar y de los tejidos blandos después de la distalización de los molares maxilares, mediante la terapia con alineadores transparentes e así identificar la significativa eficacia de la distalización de los molares. Se examinó a través de tomografía computarizada de haz cónico (CBCT) antes y después del tratamiento para medir los parámetros angulares y lineales. Todos los sujetos completaron el tratamiento con alineadores transparentes sin extracción mediante la distalización de los molares. Se realizó una prueba t pareada y una prueba t de muestras independientes para observar la diferencia entre antes y después del tratamiento y la diferencia entre el primer molar y el segundo molar, respectivamente. Los valores de p<0,05 se consideraron estadísticamente significativos. La tasa de movimiento prevista se calculó mediante la fórmula: (movimiento real (mm)/movimiento planificado (mm)) x 100 %. La mayoría de las variables de pre y postratamiento no mostraron diferencia estadística (P<0,05), excepto el ángulo SNA (P<0,05) y el labio superior/línea E lineal (P<0,01) debido a la retracción del incisivo. El primer y segundo molar revelaron un movimiento de traslación sin inclinación significativa y movimiento vertical. Los alineadores transparentes proporcionaron una alta previsibilidad (83,44 %) de la distalización del primer molar superior y del 85,14 % del segundo molar superior. Los alineadores transparentes pueden lograr efectivamente el desplazamiento distal de los molares.

Synthesis and biological evaluation of ß-ionone oriented proapoptosis agents by enhancing the ROS generation.

ß-ionone, a cyclic terpenoid compound present in many fruits, has been showed a broad spectrum of biological activities. In this paper, we synthesized a panel of ß-ionone derivatives and tested their anti-proliferation activity on cancer cell by the MTT assay. The results showed that most of the ß-ionone derivatives were more active than ß-ionone and curcumin. Particularly, the ß-ionone derivatives (1a, 1d and 1g) with ortho-substituents on the aromatic ring exhibited much stronger cytotoxicity than their corresponding meta- and para-substituted compounds. Importantly, the cytotoxicity of the ß-ionone derivatives (1a, 1d and 1g) were relationship with their reactive oxygen species (ROS)-generation abilities, which could lead to the redox imbalance, lipid peroxidation, the loss of mitochondrial membrane potential (MMP), the activation of Bax and Caspase 3, followed by cell apoptosis. This work suggest that the "ortho effect", the ROS-generation ability and drawing fluorine atom into drugs may play a potent role in enhancing the anticancer activity of ß-ionone derivatives.

UHPLC Q-Exactive MS-Based Serum Metabolomics to Explore the Effect Mechanisms of Immunological Activity of Astragalus Polysaccharides With Different Molecular Weights.

Astragalus polysaccharides (APS) have a wide range of biological activities. Most researchers discuss total APS as the main research object. However, because the relative molecular weight of APS has a wide distribution, in-depth studies on the mechanisms of the biological activity of notable molecules are limited. For example, the relationship between the immunomodulatory effect of APS and its relative molecular weight has not been clearly defined. Therefore, in this paper, we separated and obtained APS of different molecular weights by ultrafiltration technology and then constructed a mouse cyclophosphamide-induced immunosuppression model to investigate the immune activity of APS of different molecular weights. The immune enhancement mechanism of APS was explored by examining changes in routine blood indicators, body weight, immune organs, and differential metabolites in mouse serum. Results showed that APS-I (molecular weight, >2,000 kDa), APS-II (molecular weight, 1.02 × 104 Da) and APS-III (molecular weight, 286 Da) could increase the number of immune cells in mouse serum and improve immune organ damage to varying degrees. Among the samples obtained, APS-II showed the best effects. Compared with those in the blank group, 29 metabolites determined by UHPLC Q-Exactive MS in the serum of the model group changed remarkably, and APS-I, APS-II, and APS-III respectively restored 13, 25, and 19 of these metabolites to normal levels. Metabolomics analysis revealed that APS-II is mainly responsible for the immunomodulatory activity of APS. Metabolomics analysis revealed that the mechanisms of this specific molecule may involve the regulation of phenylalanine metabolism, cysteine and methionine metabolism, tricarboxylic acid cycle (TCA cycle) and arginine and proline metabolism.

Helicobacter pylori infection and gastric cancer: evidence from a retrospective cohort study and nested case-control study in China.

AIM: To explore the association between Helicobacter pylori (Hp) infection and risk of gastric cancer in China. METHODS: Utilizing gastroendoscopic biospsy tissue banks accumulated from 1980 to 1988 in Shandong, Zhejiang, and Jiangsu, where stomach cancer incidence was high, during stomach cancer screening conducted by Health Science Center of Peking University, School of Medicine of Zhejiang University, and Zhongshan Hospital of Fudan University. Warthin Starry silver staining method was applied to determine H. pylori infection status of biopsies collected during gastroendoscopic examination. In the retrospective study, the subjects were divided into two cohorts, the exposure cohort was positive H. pylori infection, and the non-exposure cohort was negative. Death from stomach cancer was determined as the outcome of the study. Logistic regression and Cox regression were applied to analyze the association between Helicobacter pylori infection and gastric cancer risk. In the nested case-control study, there were 28 deaths from gastric cancer in the fields of Muping, Shandong province, and Zhoushan, Zhejiang provinces. 4 controls were matched to each case on the basis of age (+/-5 years old), sex, residential place at the same time entered into the study. Conditional logistic regression analysis was used to analyze the data. RESULTS: There were a total of 2 719 subjects (male 1 399, female 1 320) with gastroendoscopic biopsies stored available treated as a cohort. H. pylori positive cohort included 1 671 subjects (61.5 %) and H. pylori negative cohort 1 048 subjects(38.5 %). These subjects were followed up for 1-19 years, averaged 10.88 years. The outcome of death from stomach cancer in the exposure cohort was 33, and in the non-exposure cohort 11. After adjustment for age and sex, RR=1.9850 (P=0.0491), 95 % CI was 1.0026, and 3.9301. The results of conditional logistic regression showed an OR of 4.467 and 95 % CI of 1.161, and 17.190 for the nested case control study. CONCLUSION: The results from the retrospective cohort study and the nested-case control study on the association of H. pylori infection and gastric cancer in China suggested that Helicobacter pylori infection might increase the risk of stomach cancer.