A skeleton in a huff: insights in etiologies of osteosclerosis.

A 30-yr-old man developed right lower leg pain and a palpable solid mass. Radiographic imaging revealed a periosteal reaction with an exostotic mass arising from the right distal fibula. Generalized skeletal osteosclerosis with periosteal reaction was discovered on a radiographic skeletal survey.

Silver Diamine Fluoride and Progression of Incipient Approximal Caries in Permanent Teeth: A Retrospective Study.

The purpose of this study was to evaluate the progression of incipient approximal caries lesions in permanent teeth of children and adolescents with and without silver diamine fluoride (SDF) application. A retrospective analysis of dental records and radiographs was performed. Baseline and follow-up bitewing radiographs were evaluated and scored using International Caries Classification and Management System (ICCMS) criteria to assess lesion progression.

Radiographic interpretation using high-resolution Cbct to diagnose degenerative temporomandibular joint disease.

The objective of this study was to use high-resolution cone-beam computed images (hr- CBCT) to diagnose degenerative joint disease in asymptomatic and symptomatic subjects using the Diagnostic Criteria for Temporomandibular Disorders DC/TMD imaging criteria. This observational study comprised of 92 subjects age-sex matched and divided into two groups: clinical degenerative joint disease (c-DJD, n = 46) and asymptomatic control group (n = 46). Clinical assessment of the DJD and high-resolution CBCT images (isotropic voxel size of 0.

Mandibular condylar remodeling characteristics after simultaneous condylectomy and orthognathic surgery.

Introduction: The objectives of this study were to evaluate postsurgical condylar remodeling using a radiographical interpretation, quantify condylar volumetric asymmetry, and assess soft tissue symmetry after simultaneous unilateral high condylectomy and bimaxillary osteotomies.

Methods: Sixteen patients diagnosed with unilateral condylar hyperplasia underwent unilateral high condylectomy and orthognathic surgery to correct skeletal and facial asymmetries. Cone-beam computed tomography scans were acquired before and 1-year after surgery.

Software comparison to analyze bone radiomics from high resolution CBCT scans of mandibular condyles.

Objectives: Radiomics refers to the extraction and analysis of advanced quantitative imaging from medical images to diagnose and/or predict diseases. In the dentistry field, the bone data from mandibular condyles could be computationally analyzed using the voxel information provided by high-resolution CBCT scans to increase the diagnostic power of temporomandibular joint (TMJ) conditions. However, such quantitative information demands innovative computational software, algorithm implementation, and validation.

Articular cartilage protection in Ctsk mice is associated with cellular and molecular changes in subchondral bone and cartilage matrix.

Osteoarthritis (OA) is a degenerative disease and a major cause of chronic disability in aging individuals. Cathepsin K (CatK), encoded by the Ctsk gene, has been implicated in the pathogenesis of pycnodysostosis and osteoporosis. The use of a selective inhibitor of CatK was recently shown to delay OA progression in rabbits.

Bone marrow macrophages support prostate cancer growth in bone.

Resident macrophages in bone play important roles in bone remodeling, repair, and hematopoietic stem cell maintenance, yet their role in skeletal metastasis remains under investigated. The purpose of this study was to determine the role of macrophages in prostate cancer skeletal metastasis, using two in vivo mouse models of conditional macrophage depletion. RM-1 syngeneic tumor growth was analyzed in an inducible macrophage (CSF-1 receptor positive cells) ablation model (MAFIA mice).

Polarization of prostate cancer-associated macrophages is induced by milk fat globule-EGF factor 8 (MFG-E8)-mediated efferocytosis.

Tumor cells secrete factors that modulate macrophage activation and polarization into M2 type tumor-associated macrophages, which promote tumor growth, progression, and metastasis. The mechanisms that mediate this polarization are not clear. Macrophages are phagocytic cells that participate in the clearance of apoptotic cells, a process known as efferocytosis.

Osteal macrophages support physiologic skeletal remodeling and anabolic actions of parathyroid hormone in bone.

Cellular subpopulations in the bone marrow play distinct and unexplored functions in skeletal homeostasis. This study delineated a unique role of osteal macrophages in bone and parathyroid hormone (PTH)-dependent bone anabolism using murine models of targeted myeloid-lineage cell ablation. Depletion of c-fms(+) myeloid lineage cells [via administration of AP20187 in the macrophage Fas-induced apoptosis (MAFIA) mouse model] reduced cortical and trabecular bone mass and attenuated PTH-induced trabecular bone anabolism, supporting the positive function of macrophages in bone homeostasis.

Parathyroid hormone-related protein drives a CD11b+Gr1+ cell-mediated positive feedback loop to support prostate cancer growth.

In the tumor microenvironment, CD11b(+)Gr1(+) bone marrow-derived cells are a predominant source of protumorigenic factors such as matrix metalloproteinases (MMP), but how distal tumors regulate these cells in the bone marrow is unclear. Here we addressed the hypothesis that the parathyroid hormone-related protein (PTHrP) potentiates CD11b(+)Gr1(+) cells in the bone marrow of prostate tumor hosts. In two xenograft models of prostate cancer, levels of tumor-derived PTHrP correlated with CD11b(+)Gr1(+) cell recruitment and microvessel density in the tumor tissue, with evidence for mediation of CD11b(+)Gr1(+) cell-derived MMP-9 but not tumor-derived VEGF-A.

The effects of zoledronic acid in the bone and vasculature support of hematopoietic stem cell niches.

Hematopoietic stem cells (HSC) are maintained in a tightly regulated bone microenvironment constituted by a rich milieu of cells. Bone cells such as osteoblasts are associated with niche maintenance as regulators of the endosteal microenvironment. Bone remodeling also plays a role in HSC mobilization although it is poorly defined.

The multifaceted actions of PTHrP in skeletal metastasis.

PTHrP, identified during the elucidation of mediators of malignancy-induced hypercalcemia, plays numerous roles in normal physiology as well as pathological conditions. Recent data support direct functions of PTHrP in metastasis, particularly from tumors with strong bone tropism. Bone provides a unique metastatic environment because of mineralization and the diverse cell populations in the bone marrow.

Cyclophosphamide creates a receptive microenvironment for prostate cancer skeletal metastasis.

A number of cancers predominantly metastasize to bone, due to its complex microenvironment and multiple types of constitutive cells. Prostate cancer especially has been shown to localize preferentially to bones with higher marrow cellularity. Using an experimental prostate cancer metastasis model, we investigated the effects of cyclophosphamide, a bone marrow-suppressive chemotherapeutic drug, on the development and growth of metastatic tumors in bone.

Roles of bone marrow cells in skeletal metastases: no longer bystanders.

Bone serves one of the most congenial metastatic microenvironments for multiple types of solid tumors, but its role in this process remains under-explored. Among many cell populations constituting the bone and bone marrow microenvironment, osteoblasts (originated from mesenchymal stem cells) and osteoclasts (originated from hematopoietic stem cells) have been the main research focus for pro-tumorigenic roles. Recently, increasing evidence further elucidates that hematopoietic lineage cells as well as stromal cells in the bone marrow mediate distinct but critical functions in tumor growth, metastasis, angiogenesis and apoptosis in the bone microenvironment.

Inhibitory effects of megakaryocytic cells in prostate cancer skeletal metastasis.

Prostate cancer cells commonly spread through the circulation, but few successfully generate metastatic foci in bone. Osteoclastic cellular activity has been proposed as an initiating event for skeletal metastasis. Megakaryocytes (MKs) inhibit osteoclastogenesis, which could have an impact on tumor establishment in bone.

Leptin functions peripherally to regulate differentiation of mesenchymal progenitor cells.

Leptin functions through a well-documented central neuroendocrine pathway to regulate bone mass. However, the ability of leptin to modulate bone mass through a peripheral mechanism has been debated due to conflicting in vitro results and lack of sufficient in vivo models. We utilized mice with LoxP sites introduced into the long-form leptin receptor (ObRb) gene to determine how leptin regulates mesenchymal progenitor cell (MPC) differentiation and osteoblast function in vitro and in vivo.

Influence of leucite content on slow crack growth of dental porcelains.

Objectives: To determine the stress corrosion susceptibility coefficient, n, of seven dental porcelains (A: Ceramco I; B: Ceramco-II; C: Ceramco-III; D: d.Sign; E: Cerabien; F: Vitadur-Alpha; and G: Ultropaline) after aging in air or artificial saliva, and correlate results with leucite content (LC).

Methods: Bars were fired according to manufacturers' instructions and polished before induction of cracks by a Vickers indenter (19.

Stress intensity factor threshold in dental porcelains.

The stress intensity factor threshold (KI0) is related to the stress level at which cracks start to grow stably, causing the weakening of porcelain prostheses during their use. The values of KI0 of seven dental porcelains (with and without reinforcing leucite crystal, KAlSi2O6) stored in air (22 degrees C, 60% relative humidity) and artificial saliva (37 degrees C) were determined by measuring the crack growth velocity of radial cracks generated at the corner of Vickers indentations. The results of KI0 were correlated with the leucite content, fracture toughness (KIc), and chemical composition of the porcelains.