Objective: To determine the clinical efficacy of platelet-rich plasma (PRP) injection combined with warm acupuncture and moxibustion for treating patients with knee osteoarthritis and cold dampness obstruction syndrome. Methods: One hundred and twenty-eight patients with knee osteoarthritis and cold dampness obstruction syndrome who visited the Rehabilitation Department and Orthopedics Department of the Second Affiliated Hospital of Anhui University of Chinese Medicine from January 2023 to March 2024 and who met the inclusion and exclusion criteria were randomly divided into an experimental (n=64) and control group (n=64) using the random number table method. The experimental group was treated with PRP injection combined with warm acupuncture and moxibustion, whereas the control group was treated with normal saline injection combined with warm acupuncture and moxibustion treatment. PRP and normal saline injections were administered once every two weeks, a total of four times. Patients were treated with warm acupuncture and moxibustion once a day, six times a week, for four consecutive weeks. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Traditional Chinese Medicine (TCM) syndrome, visual analog scale (VAS), and Lysholm scores were determined before treatment, at week 4 and week 8 of treatment, and week 16 of follow-up. Serum interleukin-6 (IL-6), matrix metalloproteinase-3 (MMP-3), tumor necrosis factor-α (TNF-α), osteoprotegerin (OPG), bone gla protein(BGP), and cartilage oligomeric matrix protein (COMP) levels were compared between the two groups before and after 8 weeks of treatment. The clinical efficacy and safety indicators between the two groups were also compared. Results: There was no statistical difference in baseline data such as gender, age, disease duration, and body mass index between the two groups of patients. Compared with before treatment, both groups showed decreased WOMAC total and subscale, TCM syndrome total score and symptom scores, and VAS scores, and an increase in Lysholm scores at 4, 8, and 16 weeks after treatment. After treatment, serum IL-6, MMP-3, TNF-α, and COMP levels decreased, whereas serum OPG and BGP levels increased (P<0.05). Compared with the control group, patients in the experimental group showed decreased WOMAC total and subscale, TCM syndrome total score and symptom scores, and VAS scores, and an increase in Lysholm score at 4, 8, and 16 weeks after treatment. Compared with the control group, patients in the experimental group showed decreased serum IL-6, MMP-3, TNF-α, and COMP levels and an increase in serum OPG and BPG levels after treatment (P<0.05). The total effective rate of the experimental group was 91.94%, higher than that of the control group (81.97%; P<0.05). Conclusion PRP injection combined with warm acupuncture and moxibustion can improve various TCM symptoms, improve knee joint function and bone metabolism, and reduce inflammation in patients with knee osteoarthritis and cold dampness obstruction syndrome.

Objective To analyze the levels of serum CTCs and ctDNA in NSCLC patients receiving first-line EGFR-TKI treatment, and to explore the clinical value of CTCs and ctDNA detection in assessing the efficacy of treatment for advanced lung cancer. Methods A total of 109 NSCLC patients receiving first-line EGFR-TKI treatment were enrolled. Serum tumor markers CEA, CTCs, and ctDNA were detected at baseline and after one month of treatment. Chest CT scans were performed, and treatment efficacy was evaluated based on RECIST1.1 criteria. CTCs were counted by enrichment-staining-computational algorithm to analyze malignant features, while ctDNA was assessed using digital PCR. Results Survival rate was low in patients with abnormal CEA and ctDNA tests at baseline and in patients with reduced serum CTCs after treatment. In the SD subgroup of patients with brain metastases and advanced stage, the PFS benefit was low. Conclusion Patients in the SD subgroup have significantly higher recurrence risks than those in the PR or CR subgroups. Therefore, CTC and ctDNA testing should be applied to patients in the SD subgroup to identify high-risk patients with poor response to EGFR-TKI treatment, intervene with additional treatment promptly, and obtain long progression-free survival.

BACKGROUND: Endoscopic sphincterotomy (EST) is widely used to treat common bile duct stones (CBDS); however, long-term studies have revealed the increasing incidence of recurrent CBDS after EST. Loss of sphincter of Oddi function after EST was the main cause of recurrent CBDS. Reparation of the sphincter of Oddi is therefore crucial. This study aims to investigate the effectiveness and safety of endoclip papilloplasty (ECPP) for repairing the sphincter of Oddi and elucidate its mechanism. METHODS: Eight healthy Bama minipigs were randomly divided into the EST group and the ECPP group at a 1:1 ratio, and bile samples were collected before endoscopy and 6 months later. All minipigs underwent transabdominal biliary ultrasonography for the diagnosis of cholelithiasis 6 months after endoscopy. The biliary microbiota composition and alpha and beta diversity were analyzed by 16S ribosomal RNA gene sequencing. Differential metabolites were analyzed by bile acid metabolomics to explore the predictive indicators of cholelithiasis. RESULTS: Three minipigs were diagnosed with cholelithiasis in the EST group, while none in the ECPP group showed cholelithiasis. The biliary Firmicutes/Bacteroidota (F/B) ratio was increased after EST and decreased after ECPP. The Chao1 and observed species index significantly decreased 6 months after EST ( P  = 0.017 and 0.018, respectively); however, the biliary α-diversity was similar before and 6 months after ECPP. The β-diversity significantly differed in the EST group before and 6 months after EST, as well as in the ECPP group before and 6 months after ECPP (analysis of similarities [ANOSIM]: R  = 0.917, P  = 0.040; R  = 0.740, P  = 0.035; respectively). Glycolithocholic acid (GLCA) and taurolithocholic acid (TLCA) accumulated in bile 6 months after EST. CONCLUSIONS ECPP has less impact on the biliary microenvironment than EST and prevents duodenobiliary reflux by repairing the sphincter of Oddi. The bile levels of GLCA and TLCA may be used to predict the risk of cholelithiasis.
Animals ; Swine, Miniature ; Swine ; Cholelithiasis/prevention & control* ; Sphincterotomy, Endoscopic/methods* ; Sphincter of Oddi/surgery* ; Female ; Male

ObjectiveTo dynamically observe the clinical symptoms and pathological changes in a rat model of vinorelbine-induced phlebitis via injection into the dorsalis pedis vein. MethodsTwenty-eight 11-week-old male SPF-grade SD rats were randomly divided into a model group (n=20) and a control group (n=8). The model group received a single injection of 0.1 mL vinorelbine solution (4 mg/mL) via the right hind limb dorsalis pedis vein, while the control group received an equal volume of normal saline via the same method. The occurrence and grading of phlebitis in both groups were observed and recorded daily. The volume of the injured limb was measured by the drainage method to calculate the swelling rate. The weight-bearing ratio of the injured limb was assessed using a bipedal balance pain meter, and the skin temperature of the injured limb was measured by infrared thermal imaging. These measurements were conducted for 9 consecutive days. Starting from day 1, three rats from the model group were euthanized every other day. A 1-cm segment of the vein extending proximally from the injection site was collected. Pathological changes in the vein tissue were examined by hematoxylin-eosin staining, and ultrastructural changes of the vascular endothelium were observed using scanning electron microscopy. ResultsCompared to the control group, the injected hindlimb of model rats showed redness and swelling on day 1, with the swelling rate peaking at (81.89±15.75) % on day 3 (P<0.001), then gradually alleviating and decreasing to (15.41±0.33) % by day 9 (P<0.01). Pain was observed in the affected limbs of model rats on day 1 and worsened markedly on day 3, with the weight-bearing ratio decreasing to (36.35±4.91)% (P<0.001). Meanwhile, the skin temperature of the lesion site increased, reaching (36.36±0.40) ℃ on day 5 (P<0.001). Both pain and fever returned to near normal levels by day 9. Phlebitis grading in the model group showed that 75.0% of rats were grade Ⅱ on day 1; grade Ⅲ and Ⅳ each accounted for 37.5% on day 3; from days 5 to 9, most rats exhibited cord-like veins, predominantly grade III. Venous tissue showed peripheral edema and inflammatory cell infiltration on day 1, which gradually progressed to intimal rupture, vessel wall thickening, and even lumen narrowing from day 3 to 9. The venous intima exhibited destruction of tight junctions between endothelial cells and adhesion of blood cells, progressing to roughened, wrinkled, and protruding intimal surfaces. ConclusionThe vinorelbine-induced phlebitis of dorsal foot vein in rat model is characterized by local redness, swelling, warmth, and pain from days 3 to 5, which largely resolve by day 9, although cord-like veins can still be observed. With disease progression, venous tissue develops edema, vessel wall thickening, and lumen narrowing. The venous intima shows rupture, roughening, and in some cases, complete loss.

ObjectiveTo dynamically observe the clinical symptoms and pathological changes in a rat model of vinorelbine-induced phlebitis via injection into the dorsalis pedis vein. MethodsTwenty-eight 11-week-old male SPF-grade SD rats were randomly divided into a model group (n=20) and a control group (n=8). The model group received a single injection of 0.1 mL vinorelbine solution (4 mg/mL) via the right hind limb dorsalis pedis vein, while the control group received an equal volume of normal saline via the same method. The occurrence and grading of phlebitis in both groups were observed and recorded daily. The volume of the injured limb was measured by the drainage method to calculate the swelling rate. The weight-bearing ratio of the injured limb was assessed using a bipedal balance pain meter, and the skin temperature of the injured limb was measured by infrared thermal imaging. These measurements were conducted for 9 consecutive days. Starting from day 1, three rats from the model group were euthanized every other day. A 1-cm segment of the vein extending proximally from the injection site was collected. Pathological changes in the vein tissue were examined by hematoxylin-eosin staining, and ultrastructural changes of the vascular endothelium were observed using scanning electron microscopy. ResultsCompared to the control group, the injected hindlimb of model rats showed redness and swelling on day 1, with the swelling rate peaking at (81.89±15.75) % on day 3 (P<0.001), then gradually alleviating and decreasing to (15.41±0.33) % by day 9 (P<0.01). Pain was observed in the affected limbs of model rats on day 1 and worsened markedly on day 3, with the weight-bearing ratio decreasing to (36.35±4.91)% (P<0.001). Meanwhile, the skin temperature of the lesion site increased, reaching (36.36±0.40) ℃ on day 5 (P<0.001). Both pain and fever returned to near normal levels by day 9. Phlebitis grading in the model group showed that 75.0% of rats were grade Ⅱ on day 1; grade Ⅲ and Ⅳ each accounted for 37.5% on day 3; from days 5 to 9, most rats exhibited cord-like veins, predominantly grade III. Venous tissue showed peripheral edema and inflammatory cell infiltration on day 1, which gradually progressed to intimal rupture, vessel wall thickening, and even lumen narrowing from day 3 to 9. The venous intima exhibited destruction of tight junctions between endothelial cells and adhesion of blood cells, progressing to roughened, wrinkled, and protruding intimal surfaces. ConclusionThe vinorelbine-induced phlebitis of dorsal foot vein in rat model is characterized by local redness, swelling, warmth, and pain from days 3 to 5, which largely resolve by day 9, although cord-like veins can still be observed. With disease progression, venous tissue develops edema, vessel wall thickening, and lumen narrowing. The venous intima shows rupture, roughening, and in some cases, complete loss.

ObjectiveTo explore the mechanism by which Zuoguiwan improves the pancreas development in the gestational diabetes mellitus （GDM） model by observing the effects of Zuoguiwan on the expression of key regulatory factors in different stages of pancreas development. MethodsPregnant Wistar rats were randomly assigned into blank， model， insulin detemir （20 U·kg^-1） and Zuoguiwan （1.89 g·kg^-1） groups （n=18）. GDM was induced by peritoneal injection of streptozotocin on day 6.5 （E6.5d） in the embryonic stage， and the blank group was given an equal volume of sodium citrate buffer. The modeling performance was assessed by measuring the blood glucose of pregnant rats. Except the blank group and model group， pregnant rats in other groups were administrated with corresponding drugs from E9.5d to delivery. The random blood glucose of pregnant rats was monitored， and the embryos and offspring rats were measured for the length and weighed on E12.5d， E18.5d and day 21 after birth （B21d）. The Lee's index of rats on B21d was calculated. Enzyme-linked immunosorbent assay （ELISA） was employed to measure the fasting insulin （FINS） levels of B22d rats and the Homeostasis Model Assessment for Insulin Resistance （HOMA-IR） was calculated. The serum levels of aspartate aminotransferase （AST）， alanine aminotransferase （ALT）， total bilirubin （TBIL）， total cholesterol （CHO）， triglyceride （TG）， high-density lipoprotein cholesterol （HDL）， and low-density lipoprotein cholesterol （LDL） in E18.5d pregnant rats and B22d offspring were determined. The pathological changes in the pancreas of E12.5d， E18.5d and B22d rats were observed by hematoxylin-eosin （HE） staining. Western blot was used to determine the protein levels of pancreatic duodenal homeobox 1 （Pdx1）， pancreas-specific transcription factor 1a （Ptf1a）， and sex-determining region Y-box protein 9 （Sox9） in the pancreas of E12.5d embryos， Pdx1， Nkx2 homeobox 2 （Nkx2.2）， and hairy and enhancer of split-1 （Hes1） in the pancreas of E18.5d embryos， and Pdx1， v-maf musculoaponeurotic fibrosarcoma oncogene homolog A （Mafa）， and NK transcription factor-related homeobox gene family 6 locus 1 （Nkx6.1） in the pancreas of B22d rats. ResultsCompared with the blank group， the model group showed elevated blood glucose levels in pregnant rats on B0d， E9.5d， E12.5d， E15.5d， and E18.5d （P<0.05， P<0.01）， decreased body weight and body length （P<0.01） and increased Lee's index in the offspring. In addition， the B22d offspring showed rising levels of FBG， FINS， HOMA-IR， AST， and TG （P<0.01）， a declined level of HDL （P<0.01）， and pancreatic acinous cells with edema and loose arrangement. The pregnant rats on E18.5d exhibited raised levels of ALT， AST， and TG （P<0.05， P<0.01） in the pancreas and a declined level of HDL （P<0.05）. The E12.5d embryos showed up-regulated protein levels of Pdx1， Sox9， and Ptf1a in the pancreas （P<0.01） and the E18.5d embryos exhibited down-regulated protein levels of Pdx1， Nkx2.2， and Hes1 in the pancreas （P<0.01）. The protein levels of Pdx1， Nkx6.1， and Mafa in the pancreas of B22d offspring were down-regulated （P<0.01）. Compared with the model group， the insulin group exhibited lowered blood glucose in pregnant rats on B0d， E15.5d， and E18.5d （P<0.05， P<0.01）. The offspring in all treatment groups showcased increased body weight and body length （P<0.01） and decreased Lee's index. The B22d offspring exhibited declined levels of FBG， FINS， and HOMA-IR in the insulin group （P<0.01） and lowered levels of FBG and HOMA-IR in the Zuoguiwan group （P<0.01）. The B22d offspring in all the treatment groups showed reduced levels of ALT， AST， TBIL， CHO， TG， and LDL， a raised level of HDL， and alleviated edema of pancreatic acinous cells. The pregnant rats on E18.5d demonstrated declined levels of TG and ALT （P<0.05， P<0.01） and an elevated level of HDL （P<0.05）. The pancreas of E12.5d embryos presented down-regulated protein levels of Pdx1 and Sox9 and an up-regulated protein level of Ptf1a in the insulin group （P<0.05）. The pancreas of E12.5d embryos in the Zuoguiwan group presented down-regulated protein levels of Pdx1， Sox9， and Ptf1a （P<0.01）. All the treatment groups showed up-regulated protein levels of Pdx1， Nkx2.2， and Hes1 in the pancreas of E18.5d embryos （P<0.01） and Pdx1， Nkx6.1， and Mafa in the pancreas of B22d embryos （P<0.05， P<0.01）. ConclusionZuoguiwan can promote the growth and development and ameliorate the pathological changes in the pancreas of the offspring of GDM model by regulating the expression of Pdx1 pathway-related regulatory factors in different stages of pancreas development.

OBJECTIVE To explore the effect and mechanism of embryonic intervention with Zuogui pill on the glucose tolerance in offsprings of pregnant rats with gestational diabetes mellitus. METHODS Pregnant rats were randomly divided into blank group， model group， positive control group （insulin glargine）， Zuogui pill low-， medium- and high-dose groups （4.725， 9.45， 18.9 g/kg）. In addition to the blank group， streptozotocin was injected intraperitoneally to establish a gestational diabetes mellitus rat model. From day 6 to day 18 of pregnancy， each group was given relevant medicine and distilled water intragastrically， once a day. After 21 days of birth， the body weight and body length of offsprings were recorded， and the area under the curve （AUC） was calculated through a glucose tolerance test. After 22 days of birth， fasting blood glucose （FBG）， fasting insulin （FINS） levels in serum， insulin sensitivity index （ISI）， and homeostasis model assessment of insulin resistance （HOMA-IR） were measured， and the morphological structure of pancreatic tissue was observed. The protein spectrum of pancreatic tissue was analyzed by tandem mass tag-based proteomics， and protein and mRNA expression levels of apolipoprotein A1（ApoA1）， solute carrier family 27 member 1 （Slc27a1）， kininogen 1（Kng1） and sodium/potassium-transporting ATPase subunit alpha 2 （Atp1a2）， solute carrier family 7 member 5 （Slc7a5）， solute carrier family 3 member 2 （Slc3a2）， bile acid-coenzyme A： amino acid N- acyltransferase （Baat）， eukaryotic translation initiation factor 2 subunit gamma （Eif2s3） were detected. RESULTS Compared with the model group， the body weight， body length and ISI of offsprings in the positive control group and Zuogui pill medium-dose group were significantly increased （P＜0.05）， while the glucose tolerance and islet cell proliferation were significantly improved， and the AUC， FBG， FINS and HOMA-IR were significantly decreased （P＜0.05）. There were 88 potential target proteins for the embryonic intervention of Zuogui pill in offsprings of pregnant rats with gestational diabetes mellitus，involving multiple pathways such as peroxisome proliferator-activated receptor （PPAR）， cyclic guanosine monophosphate-protein kinase G （cGMP-PKG）， fat digestion and absorption， and bile secretion. The proteins closely related to glucose metabolism and insulin resistance mainly included ApoA1， Slc27a1， Kng1， Atp1a2， Slc7a5， Slc3a2， Baat， and Eif2s3. Among them， compared with the model group， protein and mRNA expressions of Slc7a5， Slc3a2， and Baat in the pancreatic tissues of pregnant rat offsprings in the Zuogui pill medium-dose group were significantly up-regulated （P＜0.05）； protein and mRNA expressions of ApoA1， Slc27a1， Kng1， Atp1a2 and Eif2s3 were all significantly down-regulated （P＜0.05）. CONCLUSIONS The intervention of Zuogui pill in the embryonic period on offsprings of pregnant rats with gestational diabetes mellitus can improve their blood glucose levels and pancreatic pathological morphology. The mechanism may be related to the upregulation of the expressions of Slc7a5， Slc3a2， and Baat and the down-regulation of ApoA1， Slc27a1， Kng1， Atp1a2 and Eif2s3 expressions in the PPAR， cGMP-PKG， fat digestion and absorption， and bile secretion pathways.

OBJECTIVE To study the effects of peripheral blood-derived exosomes （Exo） intervened by Naozhenning （NZN） on injury of neuron cells HT22 induced by microglia BV-2 cells. METHODS Wistar rats were selected to prepare peripheral blood- derived Exo intervened by NZN （66.83 g/kg）， referred to as NZN-Exo； peripheral blood-derived Exo intervened by normal saline and piracetam （PLXT， 1.62 g/kg） were prepared using the same method， denoted as KB-Exo and PLXT-Exo respectively， and all Exo were subsequently identified. Meanwhile， BV-2 cells were stimulated with 1 μg/mL lipopolysaccharide （LPS） to prepare LPS- stimulated supernatant， and non-LPS-stimulated supernatant was prepared following the same protocol. HT22 cells were divided into four groups: KB-Exo group （treated with non-LPS-stimulated supernatant+KB-Exo）， model group （treated with LPS-stimulated supernatant+KB-Exo）， PLXT-Exo group （treated with LPS-stimulated supernatant+PLXT-Exo）， and NZN-Exo group （treated with LPS-stimulated supernatant+NZN-Exo）， with the concentration of the corresponding Exo in all groups being 50 μg/mL. After 24 hours of culture， the proliferation of HT22 cells was detected by the CCK-8 assay and EdU assay； the apoptosis of HT22 cells was detected； the microstructure of HT22 cells was observed； the contents of interleukin-1β （IL-1β）， IL-10， nuclear factor-κB （NF- κB）， and tumor necrosis factor-α （TNF-α） in HT22 cells were measured， as well as the expression levels of TNF-α， NOD-like receptor thermal protein domain associated protein 3 （NLRP3）， Caspase-1， B-cell lymphoma-2（ Bcl-2）， and Bcl-2-associated X protein （Bax）. RESULTS KB-Exo， PLXT-Exo and NZN-Exo were successfully prepared， and all Exo exhibited typical cup-shaped contours and membrane-enclosed characteristics. Compared with KB-Exo group， model group showed significantly decreased cell proliferation rates （detected by CCK-8 and EdU）， intracellular IL-10 levels， and Bcl-2 protein expression levels （P＜0.05）； while the cell apoptosis rate， intracellular levels of IL-1β， TNF-α， and NF-κB， as well as the expression levels of NLRP3， TNF-α， Caspase-1， and Bax proteins were significantly increased （P＜0.05）. Additionally， in the model group， the cells showed volume swelling， incomplete cell membrane， nucleolar rupture， significant swelling and deformation of mitochondria， and severe vacuolization. Compared with model group， the above quantitative indicators in the PLXT-Exo group and NZN-Exo group were significantly reversed （P＜0.05）， with large and round cell nuclei， intact nuclear membranes， and reduced mitochondrial vacuolization. CONCLUSIONS Peripheral blood-derived Exo intervened by naozhenning can alleviate the injury of neuronal cells HT22 by inhibiting inflammatory responses and cell apoptosis.

To address the challenges faced by current brain midline segmentation techniques, such as insufficient accuracy and poor segmentation continuity, this paper proposes a deep learning network model based on a two-stage framework. On the first stage of the model, prior knowledge of the feature consistency of adjacent brain midline slices under normal and pathological conditions is utilized. Associated midline slices are selected through slice similarity analysis, and a novel feature weighting strategy is adopted to collaboratively fuse the overall change characteristics and spatial information of these associated slices, thereby enhancing the feature representation of the brain midline in the intracranial region. On the second stage, the optimal path search strategy for the brain midline is employed based on the network output probability map, which effectively addresses the problem of discontinuous midline segmentation. The method proposed in this paper achieved satisfactory results on the CQ500 dataset provided by the Center for Advanced Research in Imaging, Neurosciences and Genomics, New Delhi, India. The Dice similarity coefficient (DSC), Hausdorff distance (HD), average symmetric surface distance (ASSD), and normalized surface Dice (NSD) were 67.38 ± 10.49, 24.22 ± 24.84, 1.33 ± 1.83, and 0.82 ± 0.09, respectively. The experimental results demonstrate that the proposed method can fully utilize the prior knowledge of medical images to effectively achieve accurate segmentation of the brain midline, providing valuable assistance for subsequent identification of the brain midline by clinicians.
Humans ; Brain/diagnostic imaging* ; Deep Learning ; Image Processing, Computer-Assisted/methods* ; Algorithms ; Magnetic Resonance Imaging/methods* ; Neural Networks, Computer

OBJECTIVE: To establish a three-dimensional finite element model of a digital wire loop space maintainer for the mandible and primary tooth loss, in order to investigate the stress, deformation, and shear force experienced by patients with the loss of the second primary molar when wearing the wire loop space maintainer. METHODS: Cone beam computed tomography (CBCT) scans were performed on the patients to create a digital model of the mandible with the absence of the second primary molar using Mimics 21.0 software. A digital model integrating the crown's retention and the wire loop structure of the full crown and ring wire loop space maintainer was constructed using pediatric space maintainer design software, utilizing three different materials: cobalt-chromium alloy, polyether ether ketone (PEEK), and titanium alloy. In ANSYS Work Beach 2023 R2 software, vertical loads of 70 N, tilted 45° along the long axis of the tooth loads of 70 N, and a 10 N load on the surface of the wire loop were applied to the occlusal surfaces of models 46 and 84, simulating centric and lateral occlusions during chewing with the wire loop space maintainer in place. The stress states of the wire loop space maintainer and supporting teeth were analyzed. RESULTS: Under various loading conditions, the maximum principal stress of the ring wire loop space maintainer was significantly lower than that of the full crown. Stress contour maps indicated that the peak of the maximum principal stress occurred at the junction of the wire loop and crown structure, indicating that this area was more susceptible to fracture. The ring wire loop space maintainer made from PEEK material exhibited the lowest maximum shear stress on the internal organizational surfaces, with equivalent stresses of 23.18 MPa and 36.35 MPa for models 46 and 84, respectively. Stress contour maps demonstrated that the maximum stress on tooth 46 was located at its mesial, while the maximum stress on tooth 84 was situated near the root area on its distal, in contact with the wire loop space maintainer. CONCLUSION In cases of second primary molar loss, wearing the digital ring wire loop space maintainer can effectively distribute stress, and the ring wire loop space maintainer made from PEEK material reduces the stress experienced by supporting teeth to some extent, demonstrating its superiority in clinical application.
Finite Element Analysis ; Humans ; Tooth, Deciduous ; Cone-Beam Computed Tomography ; Space Maintenance, Orthodontic/methods* ; Imaging, Three-Dimensional ; Orthodontic Wires ; Dental Stress Analysis ; Mandible ; Stress, Mechanical