The coordination of bimaxillary alveolar arch widths in subjects with normal occlusion or posterior crossbite: A CBCT retrospective study.

OBJECTIVES: To propose a method for evaluating the coordination of maxillomandibular alveolar arch in transverse dimension with cone-beam computed tomography (CBCT) and to apply this method to subjects with normal occlusion at different dentition stages or transverse discrepancy. MATERIALS AND METHODS: Digital data of 130 patients with normal occlusion at different dentition stages or transverse discrepancy were collected for three-dimensional reconstruction. The patients with normal occlusion were divided into Group 1 (>16 years) and Group 2 (≤16 years) based on their age. Adult patients with posterior crossbite were divided into the Group 3. According to the proposed method, the average alveolar arch coordination angle (AACA) and other parameters were analysed in each group. Group 1 was considered as the control group and compared with Group 2 and Group 3. RESULTS: Significant differences were observed in the maxillary posterior segment width among patients with normal occlusion. Group 3 demonstrated increased AACA and mandibular alveolar arch width compared with the normal occlusion group. Pearson correlation analysis indicated a positive relationship between maxillomandibular alveolar arch widths in the normal occlusion groups, with a strong correlation between AACA and the disparity in maxillomandibular widths. CONCLUSION: Adults with normal occlusion exhibit significantly wider maxillary posterior alveolar arches than adolescents, with no marked difference in mandibular widths. The posterior crossbite group showed broader mandibular alveolar arches. There was a strong correlation between AACA and the difference in maxillomandibular widths. This study's method shows potential value for orthodontic transverse diagnosis.

Three-dimensional finite element analysis of upper anterior teeth retraction and intrusion using clear aligners and mini-implants.

OBJECTIVES: This study aimed to investigate the differences in treatment outcomes of upper anterior teeth retraction and intrusion with clear aligners and different types of elastics on mini-implants via the 3D finite element method. METHODS: Cone-beam computed tomography (CBCT) was conducted to construct a 3D finite element model of maxillary bone, dentition, and clear aligners using Mimics, Geomagic, Solidworks, and Ansys. Four model groups were developed. Group 1 was the control group. Group 2 implanted a mini-implant between the upper second premolar and the upper first molar with a force of 0.98 N applied to the canine cut along the retracting direction for each side. Group 3 was based on Group 2, which implanted an additional mini-implant between the upper central incisors with a force of 0.98 N applied to the upper anterior teeth cuts. Group 4 was also based on Group 2, which implanted 2 additional mini-implants between the upper central and lateral incisors with a force of 0.56 N applied to the upper anterior teeth cuts for both sides. Anterior teeth torque changes, displacement patterns, and stress distributions were analyzed. RESULTS: Among all the experimental groups, the anterior teeth demonstrated intrusion and distal inclination, accompanied with varied degrees of torque loss. In Group 3, the maxillary and lateral incisors had the smallest sagittal coronal displacement. In Group 4, the intrusion values of the maxillary and lateral incisors were the largest among all the experimental groups. The maximum stress concentration in Group 2 was the most significant among all the experimental groups. CONCLUSIONS: Implanting the mini-implant between the central incisors for traction is conducive to torque control. By contrast, implanting the mini-implants between the central incisors and lateral incisors combined with vertical traction is conducive to simple intrusion, avoiding the "bowing effect" to a certain extent.

METTL3-Mediated lncRNA m6A Modification in the Osteogenic Differentiation of Human Adipose-Derived Stem Cells Induced by NEL-Like 1 Protein.

OBJECTIVES: This study aimed to explore the regulatory mechanism of methyltransferase3 (METTL3) -mediated long non-coding RNA (lncRNA) N6-methyladenosine (m6A) modification in the osteogenic differentiation of human adipose-derived stem cells (hASCs) induced by NEL-like 1 protein (NELL-1). MATERIALS AND METHODS: Methylated RNA immunoprecipitation sequencing (MeRIP-seq) and high- throughput sequencing for RNA (RNA-seq) were performed on hASCs. Osteogenic ability was detected by alkaline phosphatase (ALP) staining, Alizarin Red S(ARS) staining, ALP quantification and Quantitative real-time polymerase chain reaction analysis (qRT-PCR). Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis predicted the osteogenesis-related pathways enriched for the lncRNAs and identified the target lncRNAs. After overexpression and knockdown of METTL3, methylated RNA immunoprecipitation-qPCR (MeRIP-qPCR) and qRT-PCR were used to detect the levels of m6A modification and the expression of the target lncRNA, and the binding of both was confirmed by RNA binding protein immunoprecipitation (RIP) assay. The effects of lncRNA and METTL3 on phosphorylation of the key proteins of the pathway were detected by western blot analysis. RESULTS: In vitro experiments showed that METTL3 can promote osteogenic differentiation and that its expression level is upregulated. KEGG pathway analysis predicted that lncRNAs with differentially upregulated methylated peaks were enriched mostly in the mitogen-activated protein kinase (MAPK) signaling pathway, in which Serine/threonine protein kinase 3 (STK3) was the predicted target gene of the lncRNA RP11-44 N12.5. The m6A modification and expression of RP11-44 N12.5 were both regulated by METTL3. Subsequently, lncRNA RP11-44 N12.5 and METTL3 were found to regulate the phosphorylation levels of three key proteins in the MAPK signaling pathway, ERK, JNK and p38. CONCLUSIONS: This study shows, for the first time, that METTL3 can activate the MAPK signaling pathway by regulating the m6A modification and expression of a lncRNA, thereby enhancing the osteogenic differentiation of hASCs.

Synthesis of mesoporous silica-calcium phosphate hybrid nanoparticles and their potential as efficient adsorbent for cadmium ions removal from aqueous solution.

Since adsorption and nanomaterials had been respectively found to be the most promising technique and the preferred adsorbents for heavy metal ions removal, in this study, novel mesoporous silica-calcium phosphate (MS-CP) hybrid nanoparticles were synthesized by a facile one-pot method, and subsequently assessed as adsorbent for Cd2+ removal from aqueous solution. MS-CP were characterized by scanning and transmission electron microscopies, etc. The influences of initial Cd2+ concentration, contact time, solution temperature and solution pH on removal efficiency of Cd2+ were investigated in detail. The results revealed that MS-CP were nanospheres of ∼20 nm and presented a bimodal pore distribution (3.82 nm and 12.40 nm), a high surface area (314.56 m2/g) and a large pore volume (1.21 cm3/g). The Cd2+ removal experiments demonstrated that MS-CP had a high adsorption capacity due to electrostatic interaction between Cd2+ and silanol groups on MS-CP surface, as well as ion-exchange between Cd2+ and calcium in MS-CP. Additionally, removal efficiency of Cd2+ increased with increasing contact time and solution temperature, while decreased as initial Cd2+ concentration increased. The maximum adsorption capacity of Cd2+ by MS-CP was above 153 mg/L. These results suggested that the as-synthesized MS-CP could be promising adsorbent for Cd2+ removal from aqueous solution.

Amino-functionalized mesoporous silica nanoparticles as efficient carriers for anticancer drug delivery.

Amino-functionalized mesoporous silica nanoparticles (MSN-NH2) were synthesized by a post-grafting method and further studied as carriers for doxorubicin hydrochloride (DOX) delivery. The morphology, structure, and property of MSN-NH2 and DOX-loaded MSN-NH2 (DOX@MSN-NH2) were studied using various techniques, such as transmission electron microscopy, Fourier transformed infrared spectroscopy, N2 adsorption-desorption isotherms, and zeta potentials. The drug loading and release profile as well as the in vitro cell cytotoxicity were detaily investigated. The results indicated that the loading content of DOX increased with the decrease of MSN-NH2/DOX mass ratio and/or the increase of amino density. DOX@MSN-NH2 exhibited a pH-dependent drug release, drug release increased as the pH value decreased. Compared with MSN-NH2, which were neglectable cytotoxicity against non-small-cell lung cancer (A549) cells, DOX@MSN-NH2 displayed remarkable cytotoxicity toward A549 cells in dose- and time-dependent manners. It was concluded that the as-synthesized MSN-NH2 could be used as promising drug carriers for cancer therapy.