Comparison of three different types of splints and templates for maxilla repositioning in bimaxillary orthognathic surgery: a randomized controlled trial

The selection and implementation of a plan for maxillary surgery is of the utmost importance in achieving the desired outcome for the patient undergoing two-jaw orthognathic surgery. Some splint-based and splintless methods, accompanied by computer-assisted techniques, are helpful in improving surgical plan implementation. However, randomized controlled trials focused on this procedure are lacking. This study included 61 patients who underwent bimaxillary surgeries. The patients were randomly assigned to a conventional resin occlusal splint (CROS) group, a digital occlusal splint (DOS) group, or a digital templates (DT) group, in a 1:1:1 ratio. The mean linear distance between the planned and actual postoperative positions of eight selected points on the surfaces of the maxillary teeth was selected as the outcome measure. The distance was significantly smaller in the DT group (1.17±0.66mm) when compared to both the CROS group (2.55±0.95mm, P<0.05) and DOS group (2.15±1.12mm, P<0.05). However, the difference between the CROS group and DOS group was not statistically significant. These findings indicate that using digital templates results in the best performance in transferring the surgical plan to the operation environment as compared to the other two types of splints. This suggests that the application of digital templates could provide a reliable treatment option.

Shape Coexistence at Zero Spin in ^{64}Ni Driven by the Monopole Tensor Interaction

The low-spin structure of the semimagic ^{64}Ni nucleus has been considerably expanded: combining four experiments, several 0^{+} and 2^{+} excited states were identified below 4.5 MeV, and their properties established. The Monte Carlo shell model accounts for the results and unveils an unexpectedly complex landscape of coexisting shapes: a prolate 0^{+} excitation is located at a surprisingly high energy (3463 keV), with a collective 2^{+} state 286 keV above it, the first such observation in Ni isotopes. The evolution in excitation energy of the prolate minimum across the neutron N=40 subshell gap highlights the impact of the monopole interaction and its variation in strength with N.

Risk factors for bad splits during sagittal split ramus osteotomy: a retrospective study of 964 cases

To identify the potential risk factors for bad splits, we calculated the incidence of bad splits from 484 patients with 964 cases of sagittal split ramus osteotomy (SSRO) and investigated the association between the occurrence of bad splits and risk factors such as gender, patients' age, class of occlusion, unimaxillary or bimaxillary surgery, presence of the lower third molar, thickness of the ascending ramus, and the distance from the mandibular canal to the buccal cortical bone. The results showed that 40 sides (4.149%) with bad splits occurred in 36 patients (7.438%). The mean (SD) gap width from the canal to the buccal cortex for the bad split group, at 4.02 (1.20)mm, was narrower (p=0.003; OR=0.689; 95% CI=0.538 to 0.882) than the normal split group 4.80 (1.72)mm. On the contrary, no statistical significance (p>0.05) was detected between the patients with bad splits and those with normal splits for the other factors. In conclusion, SSRO patients with narrower distances from the mandibular canal to the buccal cortex were more prone to bad splits. More attention should be paid to patients with this risk factor during future surgeries.

Search for Nova Presolar Grains: γ-Ray Spectroscopy of ^{34}Ar and its Relevance for the Astrophysical ^{33}Cl(p,γ) Reaction

The discovery of presolar grains in primitive meteorites has initiated a new era of research in the study of stellar nucleosynthesis. However, the accurate classification of presolar grains as being of specific stellar origins is particularly challenging. Recently, it has been suggested that sulfur isotopic abundances may hold the key to definitively identifying presolar grains with being of nova origins and, in this regard, the astrophysical ^{33}Cl(p,γ)^{34}Ar reaction is expected to play a decisive role. As such, we have performed a detailed γ-ray spectroscopy study of ^{34}Ar. Excitation energies have been measured with high precision and spin-parity assignments for resonant states, located above the proton threshold in ^{34}Ar, have been made for the first time. Uncertainties in the ^{33}Cl(p,γ) reaction have been dramatically reduced and the results indicate that a newly identified ℓ=0 resonance at E_{r}=396.9(13)  keV dominates the entire rate for T=0.25-0.40  GK. Furthermore, nova hydrodynamic simulations based on the present work indicate an ejected ^{32}S/^{33}S abundance ratio distinctive from type-II supernovae and potentially compatible with recent measurements of a presolar grain.

THU0076 SONIC HEDGEHOG PROMOTES SYNOVIAL HYPERPLASIA AND BONE DAMAGE THROUGH P38 MAPK SIGNALING IN EXPERIMENTAL ARTHRITIS

Background:

Abnormal activation of sonic hedgehog (SHH) signaling has been found in synovium from patients with rheumatoid arthritis (RA). Inhibition of SHH signaling is reported to attenuate inflammation and cartilage damage in adjuvant-induced arthritis (AIA). Previously we have demonstrated that SHH signaling promoted the tumor-like behavior of fibroblast-like synoviocytes (FLSs) through p38 MAPKin vitro.

Objectives:

In the current study, we aim to further explore the role of SHH-p38 MAPK signaling in regulating synovial hyperplasia and bone erosion in experimental arthritis.

Methods:

Collagen-induced arthritis (CIA) mouse model was induced and the mice were injected with adenovirus associated virus (AAV) overexpressing SHH or treated with small molecule inhibitors GDC-0449. SB203580 was administrated for the inhibition of p38 MAPK. The severity of paw inflammation was graded and serum levels of TNFα, IL-6 were detected. The histological features of arthritis were evaluated by H&E staining. The bone erosion was identified by micro-CT assessment and the number and function of osteoclasts were determined.

Results:

Blockade of SHH by GDC-0449 significantly alleviated the symptoms and decreased the synovial hyperplasia, inflammatory infiltration, cartilage and bone damage in ankles of CIA. The bone erosions in the area of the metatarsophalangeal and ankle joints and production of TNFα, IL-6 were decreased by SHH inhibition. In addition, the administration of GDC-0449 significantly decreased the number of TRAP positive cells and the expression of NFATc1. On the contrary, SHH overexpression led to increased severity of arthritis and pathological changes. We also observed the accelerated bone injury accompanied with increased number and activity of osteoclasts and increased production of serum IL-6 in mice with upregulation of SHH expression. Of note, the administration of p38 MAPK inhibitor reversed the effects of SHH overexpression, with a reduction of joint swelling and histological scores. Inhibition of p38 MAPK prevented the bone erosion and decreased the number of TRAP positive cells and the expression of NFATc1, which were promoted by SHH overexpression.

Conclusion:

The study indicates that SHH promotes the synovial hyperplasia and bone erosion of CIA in a p38 MAPK-dependent manner. SHH-p38 MAPK signaling could be a potential target for the treatment of RA.

Acknowledgments:

This work was supported by grants from the National Natural Science Foundation of China (81571584, 81701609).

Disclosure of Interests:

None declared

Identification of human temporomandibular joint fibrocartilage stem cells with distinct chondrogenic capacity

OBJECTIVE

This study was aimed to identify the residence of human fibrocartilage stem cells (hFCSCs), characterize their stem cell properties and investigate the functional mechanisms which regulate fibrocartilage stem cells (FCSCs) toward chondrogenic differentiation during cartilage homeostasis and repairing.

METHODS

Cytological characteristics of hFCSCs and human orofacial mesenchymal stem cells (hOFMSCs) were analyzed. Chondrogenic potential of hFCSCs was compared with hOFMSCs both in vitro and in vivo. Regulatory role of SOX9 during FCSCs chondrogenesis was studied by shRNA interference in vitro, and by GFP⁺ FCSCs treatment in rat condylar cartilage defect model. SOX9 expression was also examined in temporomandibular joint osteoarthritis (TMJOA) patients' cartilage surface.

RESULTS

hFCSCs exhibited typical mesenchymal stem cell characteristics, with significantly stronger chondrogenic capability compared to hOFMSCs. Moreover, hFCSCs showed remarkably increased expression of SOX9. During cartilage pellet culture, there was stronger SOX9 expression in hFCSCs than hOFMSCs. SOX9 shRNA interference downregulated chondrogenic capability of hFCSCs in vitro, as well as disrupting migration and chondrogenic differentiation of GFP⁺ FCSCs toward mature chondrocytes in rat condylar cartilage defect. Of note, SOX9 expression was also found suppressed in the condylar superficial zone of TMJOA patients.

CONCLUSION

We found the existence of FCSCs in human TMJ cartilage, and characterized their distinct stem cell features. SOX9 is essential for hFCSCs chondrogenic differentiation, and a comprehensive understanding of the regulatory role of SOX9 in hFCSCs would be important for exploring potential intervention strategy of condylar cartilage degradation during TMJ disorders.

Comparison of the postoperative and follow-up accuracy of articulator model surgery and virtual surgical planning in skeletal class III patients

The aim of this study was to evaluate the postoperative and follow-up accuracy of using an intermediate occlusal splint between articulator model surgery (AMS) and virtual surgical planning (VSP) in double-jaw operations. Thirty skeletal class III patients were randomly allocated to have AMS or VSP. In the AMS group surgical planning was done through conventional articulator model surgery, and an intermediate occlusal splint made of acrylic resin was used. In the VSP group the surgical simulation was done virtually, and the same intermediate splint was used in the software and then fabricated using rapid prototyping technology. Preoperatively, one week postoperatively, and 1∼2-years later we obtained follow-up cone-beam computed tomographic (CT) images of each patient. Absolute linear differences between planned and actual outcomes, as well as planned and follow-up outcomes, were evaluated. There was no significant difference in either postoperative accuracy or follow-up accuracy between the methods, and there was no significant difference in the rate of skeletal relapse. Planning transfer by intermediate splint might therefore be the dominant factor in the final inaccuracies. The potentially greater accuracy of VSP may be realised with the help of new positioning devices instead of an intermediate splint.

A new clinical classification and treatment strategies for temporomandibular joint ankylosis

Temporomandibular joint ankylosis (TMJA) is a complicated condition that affects not only the condyle, but also the maxillofacial complex. Thus, it is often challenging to find a standardized treatment strategy for TMJA. This study was performed to analyse our experience with 95 TMJA patients over a 4-year period and develop a new classification system ('CDA'). The CDA classification system divides TMJA patients into eight different groups according to the preservability of the condyle (C), severity of the dentofacial bone deformity (D), and skeletal age (A). The 95 patients (129 ankylosed joints) were treated using different strategies based on this CDA classification. Treatment options included preserving or reconstructing the condylar head, surgical correction of jaw deformities, and close follow-up of mandibular growth. After treatment, all 129 ankylosed joints were completely released and the average maximum inter-incisal opening (MIO) increased from 3.6 ± 3.2 mm to 32.8 ± 5.4 mm, with no recurrence of ankylosis found during follow-up. In conclusion, this new CDA classification can effectively guide treatment strategies for TMJA patients. Using particular strategies for patients based on specific CDA classifications could provide optimal management to the benefit of TMJA patients.

Linking vein properties to leaf biomechanics across 58 woody species from a subtropical forest

Leaf venations have elements with relatively lower elasticity than other leaf tissue components, which are thought to contribute to leaf biomechanics. A better mechanistic understanding of relationships between vein traits and leaf mechanical properties is essential for ecologically relevant interpretation of leaf structural variations. We investigated 13 major (first to third order) and minor (>third order) vein traits, six leaf mechanical properties and other structural traits across 58 woody species from a subtropical forest to elucidate how vein traits contribute to leaf biomechanics. Across species, vein dry mass density (ρ_v ), total vein dry mass per leaf area (VMA) and minor vein diameter (VD_min ), but not the lower-order vein density (VLA_1•2 ), were positively correlated with leaf force to punch (F_p ) and force to tear (F_t ). Structural equation models showed that ρ_v and VD_min not only contribute to leaf mechanical properties directly (direct pathway), but also had impacts on leaf biomechanics by influencing leaf thickness and leaf dry mass per area (indirect pathway). Our study demonstrated that vein dry mass density and minor vein diameter are the key vein properties for leaf biomechanics. We also suggest that the mechanical characteristics of venations are potential factors influencing leaf mechanical resistance, structure and leaf economics spectrum.

Longitudinal Wobbling Motion in ^{187}Au

The rare phenomenon of nuclear wobbling motion has been investigated in the nucleus ^{187}Au. A longitudinal wobbling-bands pair has been identified and clearly distinguished from the associated signature-partner band on the basis of angular distribution measurements. Theoretical calculations in the framework of the particle rotor model are found to agree well with the experimental observations. This is the first experimental evidence for longitudinal wobbling bands where the expected signature partner band has also been identified, and establishes this exotic collective mode as a general phenomenon over the nuclear chart.

Use CT Imaging to Predict the Short-Term Outcome of Concurrent Chemoradiotherapy in Patients With Locally Advanced Esophageal Squamous Cell Carcinoma

Objective:

To extract the computed tomography (CT) imaging features of the primary lesions in patients with advanced esophageal squamous cell carcinoma (ESCC) and to study whether these imaging features can predict the short-term outcome after concurrent chemoradiotherapy (CCRT).

Methods:

From January 2014 to December 2015, a total of 49 patients with locally advanced ESCC who underwent CCRT were analyzed retrospectively. They were randomly categorized into the training and validation groups. Collection of CT imaging of patients before and intermediate stage undergoing radiotherapy. The correlations between imaging characteristics and short-term outcome were analyzed. The accuracy of cutoff value was verified by imaging characteristics of patients in validation group.

Result:

There were 38 patients in the training group and 11 patients in the validation group. 13 patients in the training group were classified as responders and 25 patients as nonresponders. According to the CT imaging before radiotherapy, there are no significant differences between responders and nonresponders. According to the CT imaging in the middle stage of radiotherapy, responders showed significantly higher Roundness than nonresponders (P = .004, 95% confidence interval [CI] = 0.0419-0.212). The areas under the ROC curves for the ability to predict significantly tumor response were 0.768 for Roundness (P = .001, 95% CI = 0.603-0.889). The cutoff value of Roundness is 0.3099. Roundness showed no significant associations with survival parameters.

Conclusions:

Computed tomography imaging in the middle stage of radiotherapy can predict the short-term outcome of concurrent chemoradiotherapy for patients with locally advanced ESCC but have no predictive effect on the total survival time.

An indel polymorphism in the 3' untranslated region of HMGB1 confers risk for hepatocellular carcinoma by regulating HMGB1 transcriptional activity in a Chinese population

The present study aimed to assess the association of rs34000982 polymorphism located in the 3'untranslated region (3'UTR) of high mobility group box 1 (HMGB1) gene and the risk of hepatocellular carcinoma (HCC), and further to explore the underlying mechanism. Genomic DNA was extracted from peripheral blood of 320 patients with HCC and 360 matched controls. Rs34000982 polymorphism was genotyped by a polymerase chain reaction-polyacrylamide gel electrophoresis assay. The genotype-phenotype association of HMGB1 mRNA and protein expression in HCC tissues with different genotypes was detected by quantitative (q) PCR assay and western blot. Vectors containing the insertion (ins)/ins or deletion (del)/del genotype of the rs34000982 polymorphism were constructed and the HMGB1 transcriptional activity affected by the rs34000982 polymorphism was detected by the luciferase assay. It was identified that the ins/ins genotype of rs34000982 significantly increased the risk of HCC compared with the del/del genotype. Further the qPCR results demonstrated that the HMGB1 mRNA expression level in HCC tissues with ins/ins genotype was 2.24 times that of HCC tissues with ins/del and del/del genotypes and there was a similar trend at protein level. In addition, the insertion allele of rs34000982 disturbed the binding of miR-636 with the 3'UTR of HMGB1, thereby increasing HMGB1 transcriptional activity in vitro. These data suggest that the rs34000982 polymorphism may contribute to HCC susceptibility, in full or at least partially through the effect on HMGB1 transcriptional activity by disturbing the binding of miR-636 with the 3'UTR of HMGB1.

Applications of Ultrafine Limestone Sorbents for the Desulfurization Process in CFB Boilers

With the stringent emission regulation taking effect, it is difficult for the conventional desulfurization technology in circulating fluidized bed (CFB) boilers to meet the requirements of ultralow SO₂ emission. Therefore, in this paper, the application of natural ultrafine limestone, with a Sauter mean diameter of less than 20 μm, was tested by conducting bench-scale, pilot-scale, and commercial-scale experiments to realize highly efficient desulfurization in CFB furnaces. In the past, such small-size limestone was considered unsuitable for CFB boilers. However, as demonstrated by bench-scale results, the desulfurization performance was clearly superior to that of coarse limestone, especially at low SO₂ concentrations. In a 3 MW_th pilot-scale CFB boiler, the ultrafine limestone exhibited competent desulfurization efficiency to that of the coarse limestone but clearly less significant catalytic effects on NOx formation. As revealed by field tests in four commercial-scale CFB boilers, when high-efficiency cyclones were applied to CFB boilers, the mass inventory of ultrafine particles was significantly increased and the residence time would be extended accordingly; thus, the ultrafine limestone can be used to achieve high desulfurization efficiency and even ultralow SO₂ emission with a favorable Ca/S ratio. Furthermore, a technical roadmap was drawn for the cost-effective control of SO₂ emission.