Objective A finite element simulation analysis of a bracketless orthodontic appliance was carried out to determine the correction amount under different working conditions.A design scheme for the bracketless orthodontic appliance was also formulated to create an orthodontic appliance formed by the fused deposition process with a personalized orthodontic effect.Methods Combined with the computed tomography data of the patient,a tooth model was reversely reconstructed.The correction amount of the tooth under tilting,twisting,and translation working conditions was established using the finite element method.Materials with different elastic moduli were chosen to make three-dimensional(3D)shaped bracketless orthodonitc appliance,and the orthodontic force was measured.Results Different correction amounts could be designed according to different working conditions so that the orthodontic appliance had a personalized treatment effect.The orthodontic force of the bracketless orthodontic appliance increased with elastic modulus and thickness.Under the given working conditions,the orthodontic force was minimal(90 mN)when the orthodontic material was at the minimum(90 mN).The orthodontic force reached its maximum value when the orthodontic material was at the maximum(61.66 N).Conclusions According to the patient's tooth condition and the size of the orthodontic force required for each step of correction in the whole correction process,the design should consider bracketless orthodontics with different elastic moduli and thicknesses to treat deformed teeth to realize the effect of staged orthodontic correction.

Objective:To investigate the relationship between the volume ratio of ischemic leukoaraiosis (LA) and cognitive level and arterial perfusion.Methods:Fifty-four patients, who was hospitalized in Dalian Central Hospital and diagnosed as LA clinically during the time of March to December in 2012, were selected to collect the information of the volume ratio of white matter disease, MoCa score and the average flow rate of carotid artery. The correlation between the volume ratio of white matter disease and MoCa score, cognitive impairment and the average flow rate of carotid artery were analyzed.Results:The volume ratio of LA lesions was negatively correlated with MOCA score ( r = -0.59, P<0.01); the volume ratio of LA lesions was negatively correlated with the mean flow rate of internal carotid artery ( r = -0.37, P<0.01). Quantity order of the area under receiver operating characteristic (ROC) curve of MoCA cognitive subgroup was as following: delayed memory (1.000)> visual space/executive function (0.970) = abstract force (0.970)> language ability (0.960)> attention (0.888). Conclusions:The larger the volume ratio of leukopathy in LA patients, the more serious the cognitive impairment, especially the cognitive impairment of impairment of memory delay, visual space/executive function, abstract ability and language ability.

BACKGROUND:How to improve the accuracy of puncture,reduce surgical damage,and improve surgical efficiency during vertebroplasty is currently one of the focuses of exploration and improvement in vertebroplasty techniques. OBJECTIVE:To explore the clinical significance of application of mixed reality technology in percutaneous vertebroplasty for spinal fractures. METHODS:Two patients with osteoporotic vertebral compression fracture in Dalian Second People's Hospital in June 2023 were selected.Before operation,128-row CT scanning of the lumbar spine was performed and the original data of digital imaging and communications in medicine(DICOM)were obtained.Visual Volume software was used to build the three-dimensional network model of vertebral compression fracture.Holographic imaging glasses were used to accurately map 3D network model images to the real world,assist the surgeon in completing preoperative simulation,explaining preoperative conditions and treatment plans,and guiding puncture and bone cement injection during surgery. RESULTS AND CONCLUSION:(1)Precise puncture was achieved with the assistance of a mixed reality technology.Postoperative imaging examination showed good bone cement filling and no obvious leakage.The postoperative symptoms of the patient were alleviated well,and they were able to move to the ground on the same day after surgery.(2)It is concluded that a mixed reality technology is helpful for preoperative surgical design and communication efficiency with patients and their families.Assisting with precise puncture during surgery,shortening surgical time,and reducing side injuries is a new and effective clinical diagnosis and treatment model,which has development potential in minimally invasive,precise,and personalized treatment of spinal surgery.

BACKGROUND:Scoliosis mainly refers to sequence abnormalities in the coronal,sagittal,and axial positions of the spine,with a Cobb angle of≥10°.The patients may experience symptoms such as unequal shoulder height and back asymmetry.Severe cases may affect the patient's cardiopulmonary function,thereby affecting their daily life.Conservative treatment can control the progression of scoliosis and avoid later surgery.Scoliosis orthosis is currently a commonly used and effective treatment measure in conservative treatment. OBJECTIVE:To summarize and analyze the current research status,hotspots,and trends of scoliosis orthoses both domestically and internationally,providing reference for related research. METHODS:Using bibliometrics and visual analysis as tools,and using a comparison between China and foreign countries as a method,this paper analyzes the literature on scoliosis orthosis journals in the past decade.Based on bibliometrics,the current status of research on scoliosis orthoses is determined.Citespace software is used to analyze key words and identify the current hotspots and future trends in scoliosis orthosis research. RESULTS AND CONCLUSION:(1)At present,the number of literature on scoliosis orthoses is still on a fluctuating upward trend.China and the United States are the main countries for research,with a literature share of over 40%.However,the average citation rate of foreign language literature by Chinese scholars is relatively low.(2)The basic fields of domestic research are mainly surgery and pediatrics,while orthotics and clinical neurology are mainly studied abroad.Among them,there is also a certain number of documents in domestic Chinese medicine,indicating that China is also engaged in the combination of Chinese and Western treatment of scoliosis.The National Natural Science Foundation of China has the highest proportion in the aspect of Chinese and foreign literature,reflecting the importance of the fund attaches to the research of scoliosis orthosis.(3)The authors with the highest number of publications are Qiu Yong and Negrini Stefano,and the most published institutions are the Spinal Surgery Department of Gulou Hospital affiliated to Nanjing University Medical College and UDICE-French Research University.Domestic and foreign authors and institutions have certain communications about this,but not closely,which requires relevant institutions and scholars to further explore and study.(4)From the research hotspots and future trends,the main treatment type is adolescent idiopathic scoliosis,while the production method of the short-column side bending orthosis is three-dimensinoal printing,and the main treatment index is convex progression.The ultimate purpose of treatment is to improve the quality of life of the patients.