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Background Degenerative joint disease (DJD) can be associated with disc displacement (DD) in temporomandibular disorder (TMD) patients. However, the relationship between different types of DDs and DJD remains unclear. Objectives To investigate the odds ratios of different types of sagittal and coronal DDs confirmed by magnetic resonance imaging (MRI) and DJD confirmed by cone‐beam computed tomography (CBCT) in TMD patients. Methods Radiographic data from 69 males and 232 females were collected for analysis. CBCT was used to diagnose DJD, with criteria including erosion, osteophytes, generalised sclerosis and cysts in the joint. Eight types of DDs were evaluated by sagittal and coronal MRIs: NA, no abnormality; SW, sideways; ADDR, anterior with reduction; ADDR+SW; ADDNR, anterior without reduction; ADDNR + SW; single SW; PDD, posterior; PDD + SW. The odds ratios of DJD in joints with different types of DDs were determined after joint correlation, age and gender adjustment. Results Compared with NA, the odds ratio of DJD in ADDR was 2.397 (95% CI [confidence interval]: 1.070–5.368), ADDR + SW was 4.808 (95% CI: 1.709–3.528), ADDNR was 29.982 (95% CI: 15.512–57.950) and ADDNR + SW was 25.974 (95% CI: 12.743–52.945). Erosion was significantly increased in ADDR, ADDR + SW, ADDNR and ADDNR + SW; osteophytes were significantly increased in ADDR + SW, ADDNR and ADDNR + SW; and generalised sclerosis and cysts were significantly increased in ADDNR and ADDNR + SW. There were no significant associations between single SW, PDD, PDD + SW and the DJD. Conclusions ADDR, ADDR+SW, ADDNR and ADDNR+SW were associated with DJD. ADDNR had a significantly higher prevalence of DJD than ADDR. There were no significant relationships between single SW, PDD, PDD + SW and the DJD.

In the present work, a chemical reaction has been performed for supramolecular gels to achieve multiple-stimuli-responsive smart soft materials. Simple chiral binaphthalene-based receptors can condense with histidine (His) to yield a Schiff base, which would help to achieve visual chiral recognition of unprotected l / d -His through gel formation along with specific selectivity toward 20 amino acids. Through intermolecular hydrogen bonds, the resultant Schiff base molecules assemble with excess His molecules to form three-dimensional (3D) networks of metastable cross-linked nanospheres and stable nanofibers in EtOH/water and MeOH/water, respectively. Significantly, this condensation reaction exhibits unique reversible and chromatic phenomena between sol–gel phase transitions in EtOH/water, which provide a way to design chemical reaction-based multivisual-change supramolecular gels for sensing and switching applications.

Mechanical force–induced external root resorption is a major clinical side effect of orthodontic treatment. Recent work has revealed that M1 macrophages play a vital role in promoting orthodontic root resorption (ORR), but the mechanism of how mechanical force stimulation increases the M1/M2 macrophage ratio in periodontal tissue is poorly understood. In the current study, we showed that C-X-C motif chemokine 12 (CXCL12)+ periodontal ligament cells (PDLCs) and C-X-C chemokine receptor type 4 (CXCR4)+ monocytes in the periodontal ligament (PDL) were significantly increased after force application with ongoing root resorption, and these effects were partially rescued after force removal in mice. The expression of CXCL12 in PDLCs was increased by force stimulation in a time- and intensity-dependent manner in vitro. Blockage of the CXCL12/CXCR4 axis using CXCR4 antagonist AMD3100 was sufficient to alleviate ORR and reverse the force-enhanced M1/M2 macrophage ratio. Further mechanism exploration showed that Ly6Chi inflammatory monocytes homed in a CXCL12/CXCR4 axis-dependent manner. The number and proportion of CD11b+ Ly6Chi inflammatory monocytes in cervical lymph nodes were significantly increased by force loading, accompanied by decreased CD11b+ Ly6Chi monocytes in the blood. These changes were blunted by intraperitoneal injection of AMD3100. In addition, blockage of the CXCL12/CXCR4 axis effectively reversed M2 suppression and promoted M1 polarization. Collectively, results indicate that force-induced CXCL12/CXCR4 axis mediates ORR by increasing the M1/M2 ratio in periodontal tissues through attracting Ly6Chi inflammatory monocytes and modulating macrophage polarization. The results also imply that AMD3100 is potentially inhibitory to root resorption.

Osteoporosis is a prevalent bone disorder characterized by bone mass reduction and deterioration of bone microarchitecture leading to bone fragility and fracture risk. In recent decades, knowledge regarding the etiological mechanisms emphasizes that inflammation, oxidative stress and senescence of bone cells contribute to the development of osteoporosis. Studies have demonstrated that heme oxygenase 1 (HO-1), an inducible enzyme catalyzing heme degradation, exhibits anti-inflammatory, anti-oxidative stress and anti-apoptosis properties. Emerging evidence has revealed that HO-1 is critical in the maintenance of bone homeostasis, making HO-1 a potential target for osteoporosis treatment. In this Review, we aim to provide an introduction to current knowledge of HO-1 biology and its regulation, focusing specifically on its roles in bone homeostasis and osteoporosis. We also examine the potential of HO-1-based pharmacological therapeutics for osteoporosis and issues faced during clinical translation.