BACKGROUND:Ankylosing spondylitis is a chronic inflammatory disease with chronic rheumatic immunity.Soft tissue ossification and fusion and spinal stiffness can cause biomechanical changes. OBJECTIVE:To reconstruct the lumbar-sacral intervertebral disc in ankylosing spondylitis patients with lumbar kyphosis by finite element analysis,and to study the range of motion of each segment of T11-S1 and the biomechanical characteristics of annulus fibrosus and nucleus pulposus. METHODS:The imaging data were obtained from an ankylosing spondylitis patient with lumbar kyphosis.The original CT image data of continuously scanned spine were imported into Mimics 21.0 in DICOM format,and T11-S1 was reconstructed respectively.The established model was imported into 3-Matic software in the format of"Stl"to reconstruct the intervertebral disc,and the fibrous intervertebral disc model was obtained.The improved model was further imported into Hypermesh software,and the vertebra,nucleus pulposus,annulus fibrosus and ligament were mesh-divided.After the material properties were given,the model was imported into ABAQUS software to observe the range of motion of each vertebral body in seven different working conditions of T11-S1,and analyze the biomechanical characteristics of each segment of annulus fibrosus and nucleus pulposus. RESULTS AND CONCLUSION:(1)The range of motion of L1 vertebrae was higher than that of other vertebrae under six different working conditions:extension,forward flexion,rotation(left and right),and lateral flexion(left and right).The maximum range of motion was 2.18° during L1 vertebral flexion,and the minimum range of motion was 0.12° during L5 vertebral extension.(2)The annular fiber flexion at L2-L3 segments was greater than the extension(P<0.05),and the annular fiber flexion at L3-L4 and L4-L5 segments was less than the extension(P<0.05).The left rotation of L1-L2 annular fibers was greater than the right rotation(P<0.05).The left flexion of the annulus was greater than the right flexion in L1-L2,L2-L3,L3-L4,L4-L5 and L5-S1 segments(P<0.05).(3)The nucleus pulposus stresses of T11-L12,L1-L2,L2-L3,L3-L4 and L4-L5 segments in forward flexion were greater than in extension(P<0.05).The left rotation of T12-L1 and L3-L4 segments was smaller than the right rotation(P<0.05),and that of T11-T12,L1-L2,and L2-L3 segments was larger than the right rotation(P<0.05).The left flexion was larger than the right flexion in the T11-S1 segment.(4)It is concluded that in ankylosing spondylitis patients with lumbar kyphosis,the minimum range of motion of the vertebral body is located at the L5 vertebral body in extension.To prevent fractures,it is recommended to avoid exercise in the extension position.During the onset of lumbar kyphosis in patients with ankylosing spondylitis,the maximum stress of the annulus fibrosus and nucleus pulposus is located in the L1-L2 segment,which is fixed and will not alter with the change of body position.The late surgical treatment and correction of deformity should focus on releasing the pressure of the annulus fibrosus and nucleus pulposus in this segment to avoid the rupture of the annulus fibrosus and the injury of the nucleus pulposus.

BACKGROUND:Ankylosing spondylitis is a progressive inflammation of spinal stiffness deformity caused by tissue ossification and fibrosis.The posture of ankylosing spondylitis patients is abnormal and their activities are limited that minor injuries can lead to thoracolumbar fractures.Traditional medical image observation limits doctors'preoperative decision planning and postoperative disease prevention for ankylosing spondylitis treatment. OBJECTIVE:Based on the spinal model of ankylosing spondylitis patients before and after posterior spinal cancellous ossification osteotomy("Y"osteotomy for short),to explore the biomechanical changes of"Y"osteotomy and fixation in the treatment of ankylosing spondylitis. METHODS:Based on the preoperative and postoperative CT images of an ankylosing spondylitis patient who went to the Second Affiliated Hospital of Inner Mongolia Medical University,a three-dimensional spine model(T11-S1)before and after"Y"osteotomy(L3 osteotomy)was reconstructed in Mimics 19.0 software.A 7.5 Nm torque was applied to the top of T11 vertebral body to simulate the movement of the spine under six conditions:flexion,extension,left bending,right bending,left rotation and right rotation.Finally,the range of motion of each vertebral body,the stress of each intervertebral disc,and the stress of the screw rod system were simulated. RESULTS AND CONCLUSION:(1)After"Y"type osteotomy and posterior fixation,the range of motion of all vertebrae in the spine decreased,and the loss rate of upper vertebrae was large(L1:77.95%).(2)The maximum stress of the spinal intervertebral disc before operation occurred at the L1-L2 segment(0.55 MPa),and the maximum stress of the spinal intervertebral disc after operation occurred at the T11-T12 segment(0.50 MPa),and the stress of intervertebral disc below T12 was far less than that before operation.(3)The maximum stress of the screw rod system(166.67 MPa)occurred in the upper and middle segments of the rod body and the root of the pedicle screw.(4)In conclusion,the"Y"type posterior fixation operation enhances the stability of the spine and reduces the range of motion of the spine.The vertebral body decompression of the fixed segment is great and the stress-shielding phenomenon of the lower vertebral body is significant.The stiffness of the rod body and the stress concentration area of the pedicle screw should be strengthened to avoid the fracture of the rod caused by stress fatigue.

Objective: To retrospectively analyze the epidemiological characteristics of supernumerary teeth in patients aged 4-18 years old and the influencing factors on the selection of anesthesia methods, and to provide a reference for the selection of anesthesia plans for children and adolescents with supernumerary teeth. Methods: This study is a retrospective study approved by the Institutional Ethics Committee. Based on clinical electronic medical record system and cone beam CT (CBCT) data, a retrospective analysis was conducted on 2 210 patients 4-18 years of age who underwent supernumerary tooth extraction at the School of Stomatology, Fourth Military Medical University from August 2019 to July 2021. Inclusion criteria: ① Age 4-18 years old; and ② The American Society of Anesthesiologists (ASA) classifies anesthesia into grades I-II; and ③ Have complete oral and anesthesia case records and relevant imaging data. Exclusion criteria: ① Incomplete medical records or unclear imaging data; and ② Patients with ASA grade II or above. Patients’ gender and age, the number of supernumerary teeth, arch, location, orientation, eruption status, reason for appointment, anxiety level, degree of cooperation, anesthesia method, and other relevant information were collected and statistically analyzed. Results: A total of 1 865 eligible patients were included, with an average age of (8.9±3.2) years old. There were more male patients (71.37%, 1 331 cases) than female patients (28.63%, 534 cases) (P < 0.001), with a gender ratio of 2.49:1. The majority of supernumerary teeth were single (75.97%, 1 417/1 865), primarily located in the maxilla (97.2%, 1 812/1 865) and the anterior dental region (94.2%, 1 757/1 865), and in a centric position (77.3%, 1 442/1 865). The majority of patients with erupted supernumerary teeth were active in seeking treatment (97.67%, 335/343). Patients with supernumerary teeth located in the maxilla and mandible bones, as well as in the nasal floor, were mainly referred to the department for diagnosis, accounting for 94.38%(1 361/1 442) and 90.00% (72/80) (χ2=1 363.24, P < 0.001), respectively. Regarding anesthesia methods, the largest proportion of patients received nitrous oxide sedation-assisted local anesthesia or nerve block anesthesia, accounting for 38.07% (710/1 865), followed by local anesthesia, accounting for 35.23% (657/1 865). The proportion of patients receiving midazolam intravenous sedation with local anesthesia or nerve block anesthesia and general anesthesia was relatively small, accounting for 20.86% (389/1 865) and 5.84% (109/1 865). Patients 13-18 years of age with supernumerary teeth in the mandibular and posterior regions and without anxiety had the highest proportion of local anesthesia use (P < 0.001). In contrast, patients who had supernumerary teeth located at the base of the nose (50%), severe anxiety (94.12%), and poor cooperation (98.18%) had the highest proportion of general anesthesia use (P < 0.001). There was no significant difference (P = 0.35) in the incidence of intraoperative and postoperative complications after the extraction of supernumerary teeth. However, the proportion of anesthesia-related complications, such as dizziness, coughing, and respiratory depression, occurring in patients who received general anesthesia was higher than local anesthesia, accounting for 3.81% (P = 0.006). Conclusion There is a gender difference in the incidence of supernumerary teeth in patients 4-18 years of age, with a higher prevalence in males. The majority of supernumerary teeth are single and located in the maxillary anterior region, predominantly in a centric position. Patients whose teeth had erupted were more likely to seek medical treatment voluntarily, while patients with supernumerary teeth located in the maxilla and mandible bones, as well as in the nasal floor were more likely to be referred to the department. Patients with high levels of anxiety, poor cooperation, young age, multiple teeth, and high surgical difficulty were more inclined to choose general anesthesia.

Alanyl-transfer RNA synthetase 2 mutation-related leukodystrophy： a case report and literature review Alanyl-transfer RNA synthetase 2（AARS2）mutation-related leukoencephalopathy（AARS2-L）is a rare adult-onset leukodystrophy，with only 32 cases reported in the literature. This article reports a case of a female patient，aged 44 years，who had progressive cognitive impairment，mental and behavioral disorders，and ovarian failure. Cranial magnetic resonance imaging showed extensive white matter demyelination in both hemispheres，and whole-exome sequencing revealed compound heterozygous mutations，c.179 C>A and c.2752 C>T，in the AARS2 gene. Therefore，the patient was diagnosed with AARS2-L with reference to clinical features. Furthermore，this article reviews and analyzes the clinical and gene expression features of the cases reported in previous studies.

Progressive encephalomyelitis with rigidity and myoclonus (PERM) is a specific subtype of the stiff-person syndrome, which is rare and difficult to diagnose clinically. A case of PERM in a 66-year-old female with a fluctuating progressive course was reported in this article. She had increased facial muscle tone, pruritus and sensory hypersensitivity mainly in the head and neck, medullary involvement syndrome and bilateral lower limb rigidity as the main clinical manifestations, and a previous history of pulmonary malignancy, thymoma, typeⅠ diabetes and Hashimoto′s thyroiditis. The patient′s serum and cerebrospinal fluid were positive for anti-glutamic acid decarboxylase antibody. The electromyogram showed a large number of motor unit potentials in the trunk and proximal extremities in the quiet state, which were significantly enhanced during spastic episodes, consistent with the electromyographic manifestations of stiff-person syndrome. The final diagnosis was PERM, and immunotherapy including gamma globulin and hormone responded well. PERM is a rare neurological autoimmune disease with atypical early symptoms, which can be easily misdiagnosed, and it requires attention to avoid delaying the diagnosis.

Objective:To study the clinical features and genotypes of neonatal Glanzmann thrombasthenia(NGT).Methods:A male neonate with NGT admitted to the Department of Neonatology of our hospital was retrospectively reviewed. CNKI, Wangfang database, VIP, the Chinese Medical Journal Full Text database, PubMed and Embase database were searched using key words '(neonate OR newborn) AND (Glanzmann thrombasthenia)' both in English and Chinese. The clinical features and genotypes of NGT were summarized and analyzed.Results:A male full-term neonate was admitted to our hospital for mass on the forehead and ecchymosis and petechiae on the body within half an hour after birth. He gradually developed subgaleal hemorrhage and severe anemia. Platelet count, mean platelet volume and coagulation functions were normal. The platelet aggregation test indicated decreased platelet aggregation rate induced by arachidonic acid and adenosine diphosphate. Genetic testing revealed two heterozygous mutations in the patient's ITGA2B gene: NM_000419.4: c.886G>A(p.Gly296Arg) and NM_000419.4: c.2855dup(p.Phe953Valfs*83). A total of 42 literature involving 44 patients (our case included) with NGT were retrieved. 33 cases (75.0%) of NGT showed ecchymosis or petechiae on the first day after birth. For 13 cases with detailed information, 5 cases with severe anemia were given erythrocyte and plasma transfusion and platelet transfusion was given in 1 case. 4 cases had homozygous variants and 4 cases showed compound heterozygous variants. 10 cases had follow-up records, including 2 cases without any bleeding and 8 cases with varying degrees of bleeding during follow-up. No deaths were reported.Conclusions:Neonates with ecchymosis and petechiae in the early postnatal period should be suspected of NGT. Blood transfusion is preferred when the indication for transfusion is met.

Objective:To explore the hotspots of the public concerns about quitting smoking before and during the coronavirus disease 2019 (COVID-19) pandemic.Methods:The monthly search index data of four key words, “the harm of smoking”，“quitting smoking”，“passive smoking” and “electronic cigarette” before the COVID-19 (from January, 2016 to December, 2019) and during the COVID-19 (from January, 2020 to December, 2020) pandemic were manually collected from the Baidu Index platform. The one-way ANOVA was used to compare the differences among annual search indexes of four keywords. The linear regression model was used to test the annual linear trend of search index of each keyword before the COVID-19, and the one-sample t-test was used to analyze the differences of the search indexes during the COVID-19 and the means before the COVID-19. Results:During 2016—2020, the annual average search index of “electronic cigarette” was the highest (1.465 million), followed by “the harm of smoking” (0.884 million) and “quitting smoking” (0.780 million), while “passive smoking” was the lowest (0.171 million). Before the COVID-19 (2016—2019), the search index of each keyword had positive cumulative growth, but there was no significant linear trend of annual change ( P>0.05). During the COVID-19 period (2020), the search index of “the harm of smoking” decreased significantly (0.794 million vs 0.907 million, P=0.011), and “quitting smoking” (0.591 million vs 0.827 million, P=0.172) and “passive smoking” (0.164 million vs 0.172 million, P=0.257) showed a downward trend, while the search index of “electronic cigarettes” bucked the trend and increased significantly (1.825 million vs 1.375 million, P=0.010). Conclusions:The public′s online attention to “electronic cigarette” increases dramatically during COVID-19 along with other information about quitting smoking decreases. There are urgent needs for strengthening regulation and monitoring of electronic cigarettes and carrying out more effective publicity of scientific methods to help quit smoking.

Abstract In order to achieve the goal of reducing the smoking rate among Chinese adults at ages of 15 years and above to below 20% by 2030, smoking cessation services require to be reinforced. The current Chinese smoking cessation service system includes short-term smoking cessation interventions and smoking cessation hotlines at the population level, and smoking cessation clinics at the individual level; however, these smoking cessation services suffer from problems of low awareness, low accessibility and low utilization rate. Based on the publications pertaining to smoking cessation services and released policy documents in China until June 2022, this review analyzes the current status, problems and causes of smoking cessation services, and proposes suggestions for improving the smoking cessation service system construction in China.

Ureteral stents play an important role in the treatment of ureteral strictures. It supports the narrow urethra and ensures the smooth flow of urine, thus alleviating the impact of ureteral stricture on kidney function. Traditional ureteral stents are prone to complications such as stones, bacterial infections, inflammation, and restenosis when indwelling in the body. This paper reviews the performance requirements of ureteral stents, introduces ureteral stents of different structures, functions, materials, and preparation as well as processing techniques, and analyzes the key problems and future research directions of ureteral stents, which provides a reference basis for the research of ideal ureteral stents.

Temporomandibular joint disorder (TMD) is one of the common diseases in stomatology caused by a variety of factors, with a high incidence rate, especially among the young people with great pressure, and difficult to treat this disease. it was easy to relapse directly affects the physical and mental health and quality of life of the patients. Psychological factors had been proved to be one of the causes of temporomandibular joint disorder, and cognitive behavioral therapy was a form of psychological therapy that has been applied to a variety of problems, including mental illnesses such as depression, anxiety, and physical symptoms like pain. Cognitive behavioral therapy (CBT) was also used in stomatology department. This paper reviewed the origin, concept formation, theory formation, characteristics and application of CBT in TMJ disorders, in order to provide more evidence for clinical practice and reduce pain for patients.