BACKGROUND: It is very important to explore an optimal loading force that can both allow effective intrusion and cause no damage to the teeth.OBJECTIVE: To investigate the optimal loading conditions, including loading force values and directions, in the intruding mechanics of maxillary anterior teeth.METHODS: A three-dimensional finite element model (3D FEM) of the maxillary anterior teeth was constructed to include the periodontal ligament (PDL), alveolar bone, and appliance (brackets and wire). The initial stress distribution and force of the maxillary anterior teeth were analyzed when the 3D FEM was loaded with different intruding force values and directions. RESULTS AND CONCLUSION: The optimal value of the intruding force for 6 anterior teeth fell within the range from 0.5 N to 1.0 N. The maximum stress was detected at the distal cervical level of the lateral incisor, and a relatively even distribution of initial stress was observed at 20° palatal deviation to the Y axis. The results suggest that using mini-screw implants at the labial region between the canine and lateral incisor and a combined 0.5-1.0 N intruding force with a distal force could be an optimal intrusion force system by which patients with normal occlusion could obtain a pure intrusion of anterior teeth.

Objectives To study the changes of hard tissue before and after orthodontic treatment for Angle's class Ⅲ malocclusion adolescence patient with maxillary front traction. Methods 20 cases of Angle's class Ⅲ malocclusion adolescence patients were treated by front traction in maxilla, while there were 20 cases of Angle's class Ⅰ malocclusion adolescence patients as the control group. Cephalometric a-nalysis was carried out before and after the treatment. Data were analyzed by SPSS11.0 system using paired t-test. Results There were significant increases in the length, anteroposterior diameter and thick-ness of maxillary sinus (P<0.05), while there was no significant differences in the site and central point of maxillary sinus(P>0.05). Conclusions It is a effective approach to change the hard tissue after ortho-dontic treatment for Angle's class Ⅲ malocclusion adolescence patient with front traction in maxillary area.

[Objectives]This study was designed to evaluate the treatment effects of a new movable molardistalization appliance for distal movement of maxillary first molars on Angle's Class Ⅲ malocclusion adolescence patients with the second premolar crowded.[Methods]Sixteen patients were treated by a new movable molardistalization appliance.Cephalometric analysis and model measurement was carried out before and after the treatment.Data were analyzed by paired t-test.[Results]The molars were distalized 5 mm during an average time of 3.8 months.There were significant increases in the Angle SNA and A-NPg(P ＜0.05).[Conclusion]it was a effective way to get space and improve patient's profiles on Angle's Class Ⅲ malocclusion adolescence patients with the second premolar crowded by the new movable molardistalization appliance.It was also conducive to patient's oral hygiene.

Objective To investigate the incidence,correlative factors and prevention of perimenopausal symptoms.Methods 146 perimenopausal women were investigated by using Kupperman menopausal index(KMI),life event scale,improved social support scale and self-made inventory.Results We got 112 available data,the incidence of perimenopausal symptoms was 75.0%,58.0%was mild,15.2%was moderate,1.8%was sevcre.The main correlative factors of perimenopausal symptoms were inhabited environment,self emotional controllability,history of gynecologic diseases,history of depression,dysmenorrhea,premenstrual syndrome,menopause,score of life eventscale,improved social support scale.Conclusions The incidence of perimenopausal symptoms is high.It is also related to factors of society,family and mentality,except hypogonadism.Preventing perimenopausal symptoms according to its cirrelative factors may decrease its incidence and enhance the life quality of women.

Objective To explore the clinical features of systemic onset of juvenile idiopathic arthritis (SoJIA) with atlantoaxial subluxation as the initial manifestation. Methods The clinical data from one SoJIA patient with atlantoaxial subluxation as the initial manifestation were retrospectively analyzed. Results A 9-year-old boy presented the head and neck movement disorder as the ifrst symptom, developed fever on the third day, then rapidly progressed on 23rd day, with a sharp decline in red blood cell, platelet, and hemoglobin, blood coagulation dysfunction, and a large number of bilateral pulmonary exudation. Ultrasonography showed excess lfuid in abdomen, chest, and pericardium. According to the 2001 version of the revised International College of Rheumatology standard, the diagnosis of SoJIA combined macrophage activation syndrome was conifrmed. Then treated with hemoperfusion, ifltration, and methylprednisolone combined with cyclosporine A, the disease was in remission. Conclusion For children with spontaneous atlantoaxial subluxation accompanied by the systemic symptoms, with no obvious skeletal deformity or acute inlfammation etc., should be alerted to the consideration of systemic juvenile idiopathic arthritis.

BACKGROUND:Distraction osteogenesis applied in patient’s canine distal movement, can greatly improve the speed of tooth movement, and protect the molar anchorage. But the researches on the traction rate, canine pulp vitality, canine periodontal tissue remodeling and the biological mechanisms of the technology are rare recently. OBJECTIVE:To evaluate the feasibility of rapid canine retraction through distraction osteogenesis of the periodontal ligament in adult patients and to monitor the pulp vitality, root resorption and periodontal remodeling of the canine. METHODS:Nine malocclusion patients were selected, and the bilateral maxil ary canine in adult patients were rapidly retracted and moved to the scheduled position using modified distraction devices. The canine distal movement distance, anchorage loss, root resorption and alveolar interval alterations were measured through intraoral radiographs, and lateral cephalograms. The pulp and periodontal of canine were mointrored. RESULTS AND CONCLUSION:The canines could be rapidly retracted to the schedualed position through distraction osteogenesis of the periodontal ligament in 12-16 days, the average amount of retraction was 7.18 mm and the canines tipped distal y (13.24±2.87)°. The anchorage loss was 0.5 mm. There was no obvious root resorption and periodontal tissue loss. The pulp vitality of the canines was decreased significantly right after distraction, but it recovered significantly after 3 months. The results indicated that periodontal ligament distraction osteogenesis can significantly accelerate canine movement speed, shorten treatment time, while protecting the molar anchorage;there was no significant adverse reaction of root resorption, loose teeth, pulp necrosis and loss of periodontal tissue. Indcating that distraction osteogenesis of periodontal ligament can move canines rapidly and effectively.

Purpose: This study evaluated the distance from the posterior root apices to the maxillary sinus floor (MSF) and the frequency of roots touching or protruding through the MSF using cone-beam computed tomography (CBCT). Materials and Methods: This study included 100 subjects divided into different vertical and anteroposterior skeletal growth patterns. On CBCT images, the distance from the posterior root apices to MSF was measured and the frequency of roots touching or protruding through the MSF was evaluated using NNT software (version 5.3.0.0; ImageWorks, Elmsford, NY, USA). Results: No statistically significant differences were found in the distance from the posterior root apices to the MSF among vertical skeletal groups (P>0.05). The palatal roots of the first molar and the palatal, mesio-buccal and disto-buccal roots of the second molars had significantly less distance from MSF in skeletal class II than in class III (P<0.05). The high-angle group had the highest frequencies of roots touching or protruding into the maxillary sinus (49.8%); the lowest proportion of these roots was found in skeletal class III (28.3%) and the highest proportion in class II (50.3%). Males had shorter distances from the posterior root apices to the MSF and higher frequencies of roots protruding through or touching the MSF than females. Conclusion Anteroposterior skeletal growth patterns and sex affected the distances from the maxillary posterior roots to the MSF. The frequency of roots protruding into or touching the sinus was affected by both vertical and anteroposterior skeletal groups and sex. These findings have implications for dental practice.

Objective:To explore the clinical immune manifestations and high risk factors of children with neuropsychiatric systemic lupus erythematosus (NPSLE), so as to find the basis for early clinical differential diagnosis, prevention and treatment of NPSLE.Methods:Ninety-four children with systemic lupus erythematosus (SLE) admitted to Hunan Children′s Hospital from January 1, 2015 to April 30, 2022 were retrospectively selected. Among them, 19 children with NPSLE were in the NPSLE group, and 75 children without NPSLE were in the SLE group. The disease activity, immune system, lymphocyte subsets, inflammatory factors and autoantibodies were compared between the two groups.Results:Among 94 children with SLE, the incidence of NPSLE was 20.21%(19/94). The most common symptoms of 19 children with NPSLE were headache, epileptic seizure and cerebrovascular disease. The Systemic Lupus Erythematosus Disease Activity Index (SLEDAI)-2000 score was (19.89±8.33)points. Most of them had a good prognosis through hormone intervention. Compared with the SLE group, NPSLE group had higher SLEDAI-2000 score, white blood cell count, urine protein, erythrocyte sedimentation rate (ESR), interferon (IFN)-α, positive rate of anti-Sm antibody and anticardiolipin antibody, lower platelet count, interleukin-2 (IL-2), C 3, C 4 level (all P<0.05), while there was no significant difference in positive rate of anti-dsDNA antibody and anti-SSA antibody between the two group (both P>0.05). Conclusions:Compared with SLE children, children with NPSLE are often complicated with many kinds of abnormal immune function, mainly abnormal humoral immune function and many kinds of positive antibody, with increased inflammatory factors.

Renal replacement therapy(RRT)is the most effective treatment for patient with severe acute kid-ney injury(AKI).But the timing of initiation of RRT remains controversial.In recent years,there has been an ongoing trend in clinical practice to initiate RRT for AKI earlier especially for patient with AKI stage 2 and severe fluid accumu-lation.There is no single target can predict the timing of discontinuation of RRT,combined use biomarker and urine volume may be a better choice in future.