BACKGROUND:One of the advantages of clear aligner treatment is molar distalization.However,tooth tilting movement and loss of anterior anchorage may occur during treatment.There are few studies on whether these problems can be improved by selecting clear aligners with different thicknesses and edges to improve the clinical treatment effect.OBJECTIVE:To analyze the control ability of clear aligners with different thickness and edges on the central incisor,lateral incisor,and second molar when pushing the maxillary second molar distally by three-dimensional finite element analysis.METHODS:Three-dimensional finite element analysis models of bilateral maxillary second molar distalization with clear aligner,maxillary dentition,periodontal ligament,and alveolar bone with different thicknesses and margins were established by Mimics,Geomagic Wrap,3-matic and SolidWorks software,respectively.There were 16 combinations of four thicknesses(0.4,0.5,0.625,and 0.75 mm)and four margins(scallop,straight,straight extension 2 mm and straight extension 4 mm).The data were imported into Ansys Workbench software for design and solution.The mean value,peak value and distribution of the periodontal ligament equivalent stress of the second molar,the equivalent stress and the maximum initial displacement of the second molar,and the control ability of each appliance on the second molar,central incisor,and lateral incisor were analyzed.RESULTS AND CONCLUSION:(1)The mean equivalent stress of periodontal ligament of the second molar,the equivalent stress of the second molar and the maximum initial displacement of the second molar increased with the extension of the appliance edge and the increase of the thickness of the appliance in the 16 groups of models.(2)When the thickness of appliances was the same,the maximum equivalent stress of the second molar in the linear appliance group was the highest,and the maximum equivalent stress of the second molar in the linear extended appliance group was greater than that in the scallop appliance group.When the edge of the appliance was the same,the periodontal ligament equivalent stress peak of the second molar increased with the increase of the thickness of the appliance.The equivalent stress distribution in the periodontal ligament of the second molar in the linear extendable appliance group was more uniform than that in the scallop appliance group and the linear appliance group.(3)When the thickness of the appliance was the same,the scallop-shaped appliance had the worst control on the second molar.When the edge of the appliance was the same,with the increase of the thickness of the appliance,the control of the second molar by the linear extender appliance was gradually stronger than that by the linear appliance.The control of the central incisor was stronger and more stable with the linear extended 2 mm appliance,while the control of the lateral incisor was stronger and more stable with the linear appliance.(4)The results showed that when using clear aligners to push molars distally,extending the edge of the appliance could improve the control of the molars and reduce the tilting movement of the teeth.The design of a straight extension margin of 2 mm for the central incisor and a straight edge for the lateral incisor can enhance the control of the anchorage incisor and reduce the labial inclination of the anterior teeth.

BACKGROUND:One of the advantages of clear aligner treatment is molar distalization.However,tooth tilting movement and loss of anterior anchorage may occur during treatment.There are few studies on whether these problems can be improved by selecting clear aligners with different thicknesses and edges to improve the clinical treatment effect.OBJECTIVE:To analyze the control ability of clear aligners with different thickness and edges on the central incisor,lateral incisor,and second molar when pushing the maxillary second molar distally by three-dimensional finite element analysis.METHODS:Three-dimensional finite element analysis models of bilateral maxillary second molar distalization with clear aligner,maxillary dentition,periodontal ligament,and alveolar bone with different thicknesses and margins were established by Mimics,Geomagic Wrap,3-matic and SolidWorks software,respectively.There were 16 combinations of four thicknesses(0.4,0.5,0.625,and 0.75 mm)and four margins(scallop,straight,straight extension 2 mm and straight extension 4 mm).The data were imported into Ansys Workbench software for design and solution.The mean value,peak value and distribution of the periodontal ligament equivalent stress of the second molar,the equivalent stress and the maximum initial displacement of the second molar,and the control ability of each appliance on the second molar,central incisor,and lateral incisor were analyzed.RESULTS AND CONCLUSION:(1)The mean equivalent stress of periodontal ligament of the second molar,the equivalent stress of the second molar and the maximum initial displacement of the second molar increased with the extension of the appliance edge and the increase of the thickness of the appliance in the 16 groups of models.(2)When the thickness of appliances was the same,the maximum equivalent stress of the second molar in the linear appliance group was the highest,and the maximum equivalent stress of the second molar in the linear extended appliance group was greater than that in the scallop appliance group.When the edge of the appliance was the same,the periodontal ligament equivalent stress peak of the second molar increased with the increase of the thickness of the appliance.The equivalent stress distribution in the periodontal ligament of the second molar in the linear extendable appliance group was more uniform than that in the scallop appliance group and the linear appliance group.(3)When the thickness of the appliance was the same,the scallop-shaped appliance had the worst control on the second molar.When the edge of the appliance was the same,with the increase of the thickness of the appliance,the control of the second molar by the linear extender appliance was gradually stronger than that by the linear appliance.The control of the central incisor was stronger and more stable with the linear extended 2 mm appliance,while the control of the lateral incisor was stronger and more stable with the linear appliance.(4)The results showed that when using clear aligners to push molars distally,extending the edge of the appliance could improve the control of the molars and reduce the tilting movement of the teeth.The design of a straight extension margin of 2 mm for the central incisor and a straight edge for the lateral incisor can enhance the control of the anchorage incisor and reduce the labial inclination of the anterior teeth.

Body weight abnormalities, including overweight, obesity, and underweight, have become a dual public health challenge in Chinese adults: overweight and obesity lead to a variety of chronic complications, while underweight increases the risks of malnutrition, sarcopenia, and organ dysfunction. To systematically address these issues, multidisciplinary experts in endocrinology, sports science, nutrition, and psychiatry from various regions have held multiple weight management seminars. Based on the latest epidemiological data and clinical evidence, they expanded the guideline to include assessment and intervention strategies for underweight, in addition to the core content of obesity management. This guideline outlines the etiological mechanisms, evaluation methods, and multidimensional management strategies for overweight and obesity, covering key areas such as diagnosis and assessment, medical nutrition therapy, exercise prescription, pharmacological intervention, and psychological support. It is intended to provide a scientific and standardized approach to weight management across the adult population, aiming to curb the rising prevalence of obesity, mitigate complications associated with abnormal body weight, and improve nutritional status and overall quality of life.

Objective To introduce the method and results of modeling validation of the treatment planning system used in the first Mevion proton therapy system in China.Methods The SOBP(Spread-Out Bragg Peak)beams in water were designed according to the TG-185 report.The treatment plans in water were designed according to the TG-350 report.The treatment plans of patients were designed on the CT images.The plane dose of each beam was measured by using the MatriXX ONE ioni-zation chambers at different depths in the water,and the measurment results were compared with the TPS calculated results to verify the accuracy of the output doses,the error requirements were 2％/2 mm.Results Except for the distal fall-off position,the doses deviation at the SOBP beams center were less than 3％,and the γ analysis pass rates of plane doses were more than 90％.The measured results of the treatment plan beams were within the tolerance of deviation,and the output doses of the beams without or with static adaptive aperture were more accurate in general.With the decrease of beam energy,the error of dose calculation will increase.Conclusion According to the accuracy requirements of the planning system calculation and treat-ment system implementation,the proton therapy system supporting the treatment planning system has been modeled.Some basic performance such as IDD and beam spot is consistent with the actual measurement,and the TPS modeling conforms to the actual performance of the machine executing when calculating the same proton radiotherapy plan.

In proton therapy,prompt gamma-ray imaging is considered as one of the most promising methods for assessing proton beam range.Prompt gamma-ray imaging detector evaluates the proton beam range based on the prompt gamma-ray distribution obtained by the prompt gamma-ray imaging system,which enables high-precision measurement of the proton beam range.Herein a proton beam range verification algorithm is designed for the newly developed prototype of the range verification detector(pixelated prompt gamma-ray imaging detector),which verifies the range estimation accuracy of the prototype for different phantoms and different energies of homogeneous media through Monte Carlo simulation.The results show that the accuracy of the proton beam range verification algorithm is within 0.5 mm of the safety margin error of the Bragg peak,and the measurement accuracy is significantly improved with the increase of the number of protons,indicating that the prototype algorithm is feasible for proton beam range verification.

Objective To introduce the method and results of modeling validation of the treatment planning system used in the first Mevion proton therapy system in China.Methods The SOBP(Spread-Out Bragg Peak)beams in water were designed according to the TG-185 report.The treatment plans in water were designed according to the TG-350 report.The treatment plans of patients were designed on the CT images.The plane dose of each beam was measured by using the MatriXX ONE ioni-zation chambers at different depths in the water,and the measurment results were compared with the TPS calculated results to verify the accuracy of the output doses,the error requirements were 2％/2 mm.Results Except for the distal fall-off position,the doses deviation at the SOBP beams center were less than 3％,and the γ analysis pass rates of plane doses were more than 90％.The measured results of the treatment plan beams were within the tolerance of deviation,and the output doses of the beams without or with static adaptive aperture were more accurate in general.With the decrease of beam energy,the error of dose calculation will increase.Conclusion According to the accuracy requirements of the planning system calculation and treat-ment system implementation,the proton therapy system supporting the treatment planning system has been modeled.Some basic performance such as IDD and beam spot is consistent with the actual measurement,and the TPS modeling conforms to the actual performance of the machine executing when calculating the same proton radiotherapy plan.

Objective:To investigate the incidence, risk factors, and outcomes of falls among the elderly community population in Beijing.Methods:A cross-sectional survey was conducted using stratified multistage random sampling to select urban and rural residents aged 65 years and older in Beijing. Mortality data was collected after the baseline survey for 5 years. The incidence of falls was weighted based on the composition ratios of age and gender from the 2010 Nation-wide Population Census of Beijing. A logistic regression model was used to analyze the impacts of demographic sociology of common chronic diseases on fall occurrence. The Cox proportional hazards regression model was used to analyze the fall and 5-year survival association.Results:A total of 2 968 participants completed the questionnaire, at cross-sectional survey, with an average age of (73.2±6.0) years, and 1 581 (53.8%) participants were female. Three hundred and sixty-one individuals experienced a fall within the past year. Among those who fell, 64 (17.7%) fell twice, and 95 (26.6%) fell three or more times. Of them, 14.4% (52) had post-fall fractures, with the wrist, knee, and hip being the most common fracture sites, accounting for 25.0%, 17.3%, and 15.4%, respectively. The weighted fall incidence was 12.4% (95% CI: 11.2%-13.5%). Aging, being female, and living in rural areas were more likely to fall. Logistic regression analysis showed that after adjusting for age, gender, and urban-rural status, the risk of falls for those living alone ( OR=1.48, 95% CI: 1.08-2.04) or living with children/grandchildren ( OR=1.51, 95% CI: 1.15-1.97) were significantly higher than those living with their spouse. In addition, the risk of falls was elevated significantly among the elderly with hypertension, diabetes, stroke, dementia, depression status, urinary incontinence, arthritis, insomnia, vision, and hearing loss, dependence on activities of daily living (ADL), general and poor self-rated health (SRH). The Cox proportional hazard regression model revealed that the 5-year risk of death increased by 65% ( HR=1.65, 95% CI: 1.29-2.11) for those who experienced a fall, which increased with fall frequency. This elevated risk persisted after adjusting for chronic conditions, ADL, and SRH. Conclusions:Ageing, female, living in rural regions, having common chronic diseases, dependence on ADL, general and poor SRH, living alone or living with children/grandchildren were associated with the elevated fall risk. The occurrence of fall was seasonal. The most common short-term adverse consequence after a fall was fractures, while the long-term effect was an increased risk of death.

Objective To establish and validate a multimodal MRI radiomics model based on intratumoral and peritumoral heterogeneity for prediction of spatial pattern of locally recurrent high-grade gliomas(HGGs).Methods A retrospective analysis was conducted on the clinical and imaging data of all HGGs patients who underwent maximum safe resection followed by postoperative radiotherapy combined with temozolomide treatment and experienced in local recurrence in Army Medical Center of PLA from 2012 to 2021.Two radiologists independently assessed the spatial patterns of locally recurrence HGGs through continuous follow-up MRI data,and primarily categorized the pattern into intra-resection cavity recurrence and extra-resection cavity recurrence.The subjected patients were randomly divided into a training set and a validation set in a 7∶3 ratio.In the training set,Pearson or Spearman correlation analysis and least absolute shrinkage and selection operator(LASSO)analysis were employed to screen radiomic features within the intratumoral and peritumoral regions,as well as to calculate radiomic scores.A radiomics model was established using logistic regression analysis.The performance of the model was assessed using calibration curves,Hosmer-Lemeshow goodness-of-fit test,and the area under the receiver operating characteristic curve(AUC).Validation of the model was performed in the validation set.Results A total of 121 patients with locally recurrent HGGs were enrolled in this study,including 54 in intra-resection cavity recurrence group and 67 in extra-resection cavity recurrence group.Among them,84 were assigned into the training set and 37 into the validation set.In the training set,the radiomics score for the extra-resection cavity recurrence group was 0.424(0.278,0.573),which was higher than that for the intra-resection cavity recurrence group[-0.030(-0.226,0.248),P<0.001].In the validation set,the radiomics score for the extra-resection cavity recurrence group was 0.369(0.258,0.487),which was higher than that for the intra-resection cavity recurrence group[0.277(0.103,0.322),P=0.033].The established radiomics model exhibited good calibration and performed well in predicting spatial recurrence patterns,with an AUC value of 0.844(95%CI:0.749～0.914)in the training set and 0.706(95%CI:0.534～0.844)in the validation set.Conclusion Our multimodal radiomics model combined with intratumoral and peritumoral heterogeneity can predict the spatial pattern of locally recurrent HGGs,providing a basis for individualized treatment of HGGs.

Objective To explore the effect of the method of cooling blood and removing stasis on promoting the relief of swelling and pain symptoms and the recovery of joint mobility in the early stage of acute ankle sprains.Methods From January 2023 to January 2024,a total of 88 patients with early-stage acute ankle sprains admitted to the Eighth Clinical Medical School of Guangzhou University of Chinese Medicine(Foshan Hospital of Traditional Chinese Medicine)were selected.The patients were randomly divided into an observation group and a control group using a random allocation method(random number table),with 44 patients in each group.The control group was treated following the PRICE principle for acute sports injury,with the measures such as ice compress,immobilization,and compression.The observation group,in addition to receiving the same treatment as the control group,was given the decoction of Liangxue Quyu Prescription orally(a formula with the actions of cooling blood and removing stasis,and composed of Ilicis Pubescentis Radix,Paeoniae Radix Rubra,Moutan Cortex,Rehmanniae Radix,Achyranthis Bidentatae Radix,Jujubae Fructus,and Glycyrrhizae Radix et Rhizoma),and external washing with Shujin Xi External Washing Granules(mainly composed of Clematidis Radix et Rhizoma,Sappan Lignum,Artemisiae Anomalae Herba,Uncariae Ramulus cum Uncis,and Glechomae Herba,and others.The treatment period for both groups lasted for one week.Before and after treatment,the changes in Visual Analogue Scale(VAS)scores of pain,ankle swelling scores,ankle range of motion(including plantar flexion and dorsiflexion),and the American Orthopedic Foot&Ankle Society(AOFAS)ankle-hindfoot scale scores in the two groups were observed.After treatment,the clinical efficacy of the two groups was evaluated.Results(1)After one week of treatment,the total effective rate in the observation group was 95.45%(42/44),and that in the control group was 86.36%(38/44).The intergroup comparison by chi-square test showed that the efficacy of the observation group was significantly superior to that of the control group(P＜0.05).(2)After treatment,the VAS scores for pain in both groups were significantly reduced(P＜0.05)and the AOFAS scores for ankle function were significantly increased(P＜0.05)compared to those before treatment.The observation group showed significant reduction in VAS scores and obvious improvement in AOFAS scores compared to the control group(P＜0.05 or P＜0.01).(3)After treatment,the ankle swelling scores in both groups were significantly reduced(P＜0.05)and the ankle range of motion was significantly improved(P＜0.05)compared to those before treatment.The observation group showed significant reduction in ankle swelling scores and obvious improvement in the range of motion compared to the control group(P＜0.05 or P＜0.01).(4)After treatment,the scores for TCM symptoms of pain,ecchymosis and swelling,and scores of functional disorders in both groups were significantly reduced(P＜0.05)compared to those before treatment.The observation group showed significant reduction in pain,ecchymosis,and swelling scores compared to the control group(P＜0.01),while there was no significant difference in dysfunction scores between the two groups after treatment(P＞0.05).Conclusion The method of cooling blood and removing stasis has significant effects on improving swelling and pain symptoms during the early treatment of acute ankle sprains.It is effective on relieving swelling and pain,and is helpful for promoting the recovery of ankle joint function.

Body weight abnormalities, including overweight, obesity, and underweight, have become a dual public health challenge in Chinese adults: overweight and obesity lead to a variety of chronic complications, while underweight increases the risks of malnutrition, sarcopenia, and organ dysfunction. To systematically address these issues, multidisciplinary experts in endocrinology, sports science, nutrition, and psychiatry from various regions have held multiple weight management seminars. Based on the latest epidemiological data and clinical evidence, they expanded the guideline to include assessment and intervention strategies for underweight, in addition to the core content of obesity management. This guideline outlines the etiological mechanisms, evaluation methods, and multidimensional management strategies for overweight and obesity, covering key areas such as diagnosis and assessment, medical nutrition therapy, exercise prescription, pharmacological intervention, and psychological support. It is intended to provide a scientific and standardized approach to weight management across the adult population, aiming to curb the rising prevalence of obesity, mitigate complications associated with abnormal body weight, and improve nutritional status and overall quality of life.