BACKGROUND: Bisphosphonate (BP) can treat osteoporosis and prevent osteoporotic fractures in clinical. However, the effect of BP on microstructure and mechanical properties of cortical and trabecular bone has been taken little attention, separately.
METHODS: In this study, BP was used to intervene in ovariectomized female SD rats. The femoral micro-CT images were used to measure the structural parameters and reconstruct the 3D models in volume of interest. The structural parameters of cortical and trabecular bone were measured, and the mechanical properties were predicted using micro-finite element analysis.
RESULTS: There was almost no significant difference in the morphological structure parameters and mechanical properties of cortical bone between normal, ovariectomized (sham-OVX) and BP intervention groups. However, BP could significantly improve bone volume fraction (BV/TV) and trabecular separation (Tb.SP) in inter-femoral condyles (IT) (sham-OVX vs. BP, p < 0.001), and had no significant effect on BV/TV in medial and lateral femoral condyles (MT, LT). Similarly, BPs could significantly affect the effective modulus in IT (sham-OVX vs. BP, p < 0.001), and had no significant difference in MT and LT. In addition, the structural parameters and effective modulus showed a good linear correlation.
CONCLUSIONS: In a short time, the effects of BP intervention and osteoporosis on cortical bone were not obvious. The effects of BP on trabecular bone in non-main weight-bearing area (IT) were valuable, while for osteoporosis, the main weight-bearing area (MT, LT) may improve the structural quality and mechanical strength of trabecular bone through exercise compensation.

A complete three-dimensional reconstruction of the internal damage (oviposition holes, entry and exit galleries, cavities caused by fungal infection) of three destructive pests of olive fruit was obtained using micro-computed tomography. In the case of the olive fruit fly (Bactrocera oleae), complete reconstruction of the galleries was achieved. The galleries were colour-coded according to the size of the internal lumens produced by larval instars. In the case of the olive moth (Prays oleae), we confirmed that the larvae only consume olive stones, leaving pulp tissue intact. This study revealed the evolutionary defensive adaptation developed by larvae, creating entrance/exit gallery in the form of a zigzag with alternating angles to avoid the action of possible parasitoids. In the case of olive fruit rot, caused by fungal infection transmitted by the midge (Lasioptera berlesiana), microtomography revealed the infection cavity, which was delimited by a protective layer of tissue produced by the plant to isolate the infection zone, which contained fungal hyphae and reproductive organs of the fungus. Two ovoid cavities were observed below a single external orifice in the concave necrotic depression. These results were interpreted as successive ovipositions of B. oleae, followed by the parasitoid L. berlesiana. High-resolution 3D rendered images are included as well as supplementary videos that could be useful tools for future research and teaching aids.

Here we describe a dataset of freely available, readily processed, whole-body μCT-scans of 56 species (116 specimens) of Lake Malawi cichlid fishes that captures a considerable majority of the morphological variation present in this remarkable adaptive radiation. We contextualise the scanned specimens within a discussion of their respective ecomorphological groupings and suggest possible macroevolutionary studies that could be conducted with these data. In addition, we describe a methodology to efficiently μCT-scan (on average) 23 specimens per hour, limiting scanning time and alleviating the financial cost whilst maintaining high resolution. We demonstrate the utility of this method by reconstructing 3D models of multiple bones from multiple specimens within the dataset. We hope this dataset will enable further morphological study of this fascinating system and permit wider-scale comparisons with other cichlid adaptive radiations.

OBJECTIVE: This study aimed to evaluate the reliability and accuracy of an intraoral ultrasound (US) device to evaluate alveolar bone by comparing it between different raters and to microCT (µCT) measurements.
METHODS: 38 teeth distributed across three human cadavers were prepared by placing two notches on the facial enamel surface. The maxillary and mandibular teeth were imaged with a custom-designed intraoral 20 MHz ultrasound and µCT with 0.03 mm voxel size. µCT was considered the reference standard for this study. For each sample, the distance from the inferior border of the most apical notch to the tip of the alveolar bone crest on the facial aspect of the teeth was measured from the US and µCT images. Intraclass correlation coefficient (ICC) and standard deviation were calculated.
RESULTS: The intra-examiner and inter-examiner reliability for both the µCT and US alveolar bone measurements were found to be excellent (intra-examiner ICC was 0.998 for µCT and 0.997 for US, inter-examiner ICC was 0.996 for µCT and between 0.947 and 0.950 for US). The accuracy of the US was found to be good compared to µCT (ICC between 0.885 and 0.894).
CONCLUSIONS: The study demonstrated that intraoral ultrasound is highly reliable and accurate compared to the µCT reference standard for evaluating facial alveolar bone height.

The development of synthetic bone substitutes that equal or exceed the efficacy of autologous graft remains challenging. In this study, a rat calvarial defect model was used as a reference to investigate the influence of composition and architecture of 3D-printed cement, with or without bioactives, on tissue regeneration. Printable cement pastes were formulated by combining hyaluronic acid and cement precursors. Cementitious scaffolds were printed with 3 different patterns. After 7 weeks of implantation with or without bone marrow, multiparametric qualitative and quantitative assessments were performed using µCT, SEM, and histology. None of the set-up strategies was as efficient as autologous cancellous bone graft to repair calvarial defects. Nonetheless, the presence of scaffold improved the skull vault closure, particularly when the scaffold was soaked in total bone marrow before implantation. No significant effect of scaffold macro-architecture was observed on tissue mineralization. Magnesium phosphate-based scaffolds (MgP) seemed to induce higher bone formation than their calcium-phosphate-based counterparts. They also displayed a quicker biodegradation and sparse remaining material was found after 7 weeks of implantation. Although further improvements are required to reach clinical settings, this study demonstrated the potential of organo-mineral cements for bone regeneration and highlighted the peculiar properties of MgP-based cements.

OBJECTIVE: To investigate whether the inhibition of 12/15-lipoxygenase (12/15-LOX), one of the core enzymes of the arachidonic acid cascade, suppresses orthodontically induced root resorption (OIRR), and examine the involvement of the hyaline degeneration of periodontal ligament cells and odontoclast differentiation.
METHODS: The left maxillary first molars of 10-week-old male Wistar rats were moved mesially for 14 days using a closed-coil spring (25 cN) inserted between the first molar and incisor. The rats were intraperitoneally administered with a 12/15-LOX specific inhibitor (ML-351; 0.05 mmol/kg) daily in the experimental group or vehicle (dimethyl sulfoxide) in the control group. Tooth movement was measured using microcomputed tomography on day 14. The appearance of OIRR, hyaline degeneration, osteoclasts, and odontoclasts was evaluated via histological analysis. Immunohistochemical staining for receptor-activated NF-kB ligand (RANKL) and osteoprotegerin was performed.
RESULTS: OIRR observed on day 14 in the control group was strongly suppressed by ML-351 treatment. Hyaline degeneration observed on the compression side on day 3 and the appearance of osteoclasts and odontoclasts on days 3 and 14 were significantly suppressed by ML-351. RANKL expression on day 3 was significantly suppressed by ML-351. These key processes in OIRR were substantially suppressed by ML-351 treatment.
CONCLUSIONS: Inhibition of 12/15-LOX reduced OIRR by suppressing hyaline degeneration and subsequent odontoclast differentiation.

Identifying evidence of human modification of extinct animal remains, such as Pleistocene megafauna, is challenging due to the similarity of anthropogenic and non-anthropogenic taphonomic features observed under optical microscopy. Here, we re-investigate a Late Pleistocene ground sloth tooth from northeast Brazil, previously suggested as human-modified based only on optical observation. To characterize the macro- and micro-morphological characteristics of the marks preserved in this tooth and evaluate potential human modification, we used stereomicroscope and scanning electron microscopy (SEM) supplemented by energy dispersive spectroscopy (EDS), UV photoluminescence (UV/PL), synchrotron-based X-ray fluorescence (SR-XRF), and synchrotron micro-computed tomography (SR-µCT). These methods allowed us to discriminate non-anthropogenic taphonomic features (root and sedimentary damage), anthropogenic marks, and histological features. The latter shows the infiltration of exogenous elements into the dentine from the sediments. Our evidence demonstrates the sequence of anthropogenic and non-anthropogenic taphonomic modification of this tooth and supports its initial intentional modification by humans. We highlight the benefits of emerging imaging and spectral imaging techniques to investigate and diagnose human modification in fossil and archaeological records and propose that human modification of tooth tissues should be further considered when studying possibly anthropogenically altered fossil remains.

Artificial light at night (ALAN) is an increasingly pervasive pollutant that alters animal behaviour and physiology, with cascading impacts on development and survival. Recent evidence links exposure to ALAN with neural damage, potentially due to its action on melatonin synthesis, a powerful antioxidant. However, these data are scarce and taxonomically limited. Here, we used micro-CT to test the effects of short-term ALAN exposure on brain volumes in the Australian garden orb-weaving spider (Hortophora biapicata), a species commonly found in urban areas and, specifically, around street lights. We found that short-term ALAN exposure was linked to reductions in the volumes of brain structures in the primary eye visual pathway, potentially as a consequence of oxidative stress or plastic shifts in neural investment. Although the effects of ALAN were subtle, they provided new insights into potential mechanisms underpinning the behavioural and physiological impacts of ALAN in this important urban predator.

The interconnected structures in a 3D scaffold allows the movement of cells and nutrients. Therefore, this study aimed to investigate the in-vivo bioactivity of 3D-printed β-tricalcium phosphate (β-TCP) and hydroxyapatite (HAP) scaffolds that replicate biological bone. This study included 24-week-old male New Zealand white rabbits. A cylindrical bone defect with a diameter of 4.5 mm and a depth of 8 mm was created in the lateral aspect of the distal femur. A 3D-printed scaffold was implanted in the right femur (experimental side), whereas the left femur was kept free of implantation (control side). Micro-CT analysis and histological observations of the bone defect site were conducted at 4, 8, and 12 weeks postoperatively to track the bone repair progress. No evidence of new bone tissue formation was found in the medullary cavity of the bone defect on the control side. In contrast, on the experimental side, the 3D scaffold demonstrated sufficient bioactivity, leading to the growth of new bone tissue. Over time, new bone tissue gradually extended from the periphery toward the center, a phenomenon evident in both micro-CT images and biopsy staining. In the current study, we observed that the cells involved in bone metabolism adhered, spread, and proliferated on our newly designed 3D-printed scaffold with a bone microstructure. Therefore, it is suggested that this scaffold has sufficient bioactivity to induce new bone formation and could be expected to be a more useful artificial bone than the existing version.

OBJECTIVE: To establish an animal model of oral squamous cell carcinoma invading the mandible through multi-sample experiments that verified the stability, repeatability, tumorigenicity and mandible destruction rate of the model.
METHODS: Oral squamous cell carcinoma cell suspension was injected into the outer side of the mandible through the anterior edge of the masseter muscle of naked mice to observe the tumourforming process. Then, the anatomical, histological and imaging examinations were carried out to determine whether the tumour had invaded the mandible. By comparing the tumour growth of multiple groups of various squamous cell carcinoma cells (CAL27, HN6 and HN30 cells), the changes in body weight and characteristics of tumour formation were compared, and the experience was summarised to further verify the stability, repeatability, tumour formation rate and arch damage rate of the model.
RESULTS: The subsequent specimens of tumour-bearing nude mice were validated once the model had been established. In vitro, tumour tissue wrapped around the mandible\'s tumour-bearing side, and the local texture was tough with no resistance to acupuncture. Haematoxylin and eosin staining revealed that squamous cells were infiltrating the mandible in both the horizontal and sagittal planes. Microcomputed tomography results showed that the mandible on the tumour-bearing side displayed obvious erosion damage. Cell lines with various passage rates clearly had diverse tumour-bearing life cycles.
CONCLUSIONS: This study successfully established an animal model of oral squamous cell carcinoma invasion of the mandible. The model has excellent biological stability, repeatability, tumorigenesis rate and mandible destruction rate.