Inherent physical characteristics and gene expression differences between alveolar and basal bones.

Objectives: The objective of this study was to evaluate the baseline differences between alveolar and basal areas of the rat mandible.

Study Design: Rat mandibular alveolar and basal bones were evaluated using histology and micro-computed tomography to compare osteocyte number as well as bone density and architecture and polymerase chain reaction to measure gene expression levels.

Results: Micro-computed tomography data indicated that basal bone is denser and less porous than alveolar bone.

Dentate transport discs can be used to reconstruct large segmental mandibular defects.

Purpose: This study tested the use of a dentate transport segment for the reconstruction of a large U-shaped defect in the anterior segment of the canine mandible using a novel curved reconstruction plate. The quality and quantity of bone regenerate formed by dentate versus edentulous transport segments were compared.

Materials And Methods: In 5 adult foxhound dogs, a defect of 70 to 75 mm was created in the canine mandible by excising the mandible anterior to the right and left fourth premolars.

Effect of metformin on periimplant wound healing in a rat model of type 2 diabetes.

Purpose: To investigate the effects of hyperglycemia and metformin (a popular biguanide antidiabetic) on periimplant healing.

Methods: Thirty-six male rats were assigned to 3 groups: (1) nondiabetic Wistar-Kyoto rats (controls), (2) Goto-Kakizaki (GK) spontaneously diabetic rats (GK group), and (3) GK rats were fed metformin (100 mg/kg body weight per day) in their water for 4 weeks (GK + Met group). The right maxillary first molars were extracted and sites were allowed 1 month to heal.

Vascular alterations in the sprague-dawley rat mandible during intravenous bisphosphonate therapy.

Long-term use of intravenous bisphosphonates, such as zoledronic acid (zoledronate), has been linked to bisphosphonate-related osteonecrosis of the jaw (BRONJ). Invasive dental surgery seems to trigger the bone necrosis in most cases. To determine the effects of zoledronic acid on the vascular structure of the rat mandible.

Secondary lymphoid organ homing phenotype of human myeloid dendritic cells disrupted by an intracellular oral pathogen.

Several intracellular pathogens, including a key etiological agent of chronic periodontitis, Porphyromonas gingivalis, infect blood myeloid dendritic cells (mDCs). This infection results in pathogen dissemination to distant inflammatory sites (i.e.

Regulation of vitamin C transporter in the type 1 diabetic mouse bone and bone marrow.

A number of studies have revealed that Type I diabetes (T1D) is associated with bone loss and an increased risk of fractures. T1D induces oxidative stress in various tissues and organs. Vitamin C plays an important role in the attenuation of oxidative stress; however, little is known about the effect of T1D induced oxidative stress on the regulation of vitamin C transporter in bone and bone marrow cells.

Osseointegration of dental implants placed into canine mandibular bone regenerated by bone transport distraction osteogenesis.

Purpose: The purpose of this study was to compare the osseointegration of dental implants placed in canine mandibular bone and in regenerated bone produced by bone transport distraction osteogenesis.

Materials And Methods: Ten adult foxhounds were divided into two groups of five animals each. In all animals, a 40-mm defect was created on one side of the mandible.

Alveolar ridge augmentation for implant fixation: status review.

This literature review was performed to illustrate and compare different alveolar ridge augmentation procedures before dental implant placement. The review was based on clinical and research studies listed in Pubmed. There is not enough evidence to support any single method as gold standard for any given condition, and choice seemed to be based on personal preferences.

Delayed versus immediate reconstruction of mandibular segmental defects using recombinant human bone morphogenetic protein 2/absorbable collagen sponge.

Purpose: To compare the efficiency of recombinant human bone morphogenetic protein 2 (rhBMP2)/absorbable collagen sponge (ACS) in the delayed versus immediate reconstruction of mandibular segmental defects in a canine model.

Methods: We randomized 11 dogs into 2 groups: immediate reconstruction (group 1, n = 6) and delayed reconstruction (group 2, n = 5). A 35-mm osteoperiosteal segmental defect was created on the left side of the mandible.

Sodium-dependent vitamin C transporter SVCT2: expression and function in bone marrow stromal cells and in osteogenesis.

Ascorbic acid (Vitamin C) has a critical role in bone formation and osteoblast differentiation, but very little is known about the molecular mechanisms of ascorbic acid entry into bone marrow stromal cells (BMSCs). To address this gap in knowledge, we investigated the identity of the transport system that is responsible for the uptake of ascorbic acid into bone marrow stromal cells (BMSCs). First, we examined the expression of the two known isoforms of the sodium-coupled ascorbic acid transporter, namely SVCT1 and SVCT2, in BMSCs (Lin-ve Sca1+ve) and bone at the mRNA level.

NF-κB2 mutation targets survival, proliferation and differentiation pathways in the pathogenesis of plasma cell tumors.

Background: Abnormal NF-κB2 activation has been implicated in the pathogenesis of multiple myeloma, a cancer of plasma cells. However, a causal role for aberrant NF-κB2 signaling in the development of plasma cell tumors has not been established. Also unclear is the molecular mechanism that drives the tumorigenic process.

Renal distal tubule proliferation and increased aquaporin 2 level but decreased urine osmolality in db/db mouse: treatment with chromium picolinate.

Hallmark features of type 2 diabetes mellitus include glucosuria and polyuria. Further, renal aquaporin 2 is pivotal to regulation of fluid excretion and urine osmolality. Accordingly, we tested the hypothesis that the db/db mouse displays increased glucosuria and fluid excretion but reduced urine osmolality in association with decreased renal aquaporin 2 level.

Difference in soft tissue response between immediate and delayed delivery suggests a new mechanism for recombinant human bone morphogenetic protein 2 action in large segmental bone defects.

The ability of recombinant human bone morphogenetic protein 2 on absorbable collagen sponge (rhBMP2/ACS) to regenerate bone in segmental defect has been well characterized. However, clinical results of rhBMP2/ACS constructs in secondary reconstruction of large mandibular and craniofacial defects have not been consistent. We hypothesized that rhBMP2 delivery triggers an endogenous response in the soft tissues surrounding the defect, in the form of expression of BMP2 and vascular endothelial growth factor (VEGF).

Development of a rat model of bisphosphonate-related osteonecrosis of the jaw (BRONJ).

The purpose of this study was to develop a rat model predictive of bisphosphonate-related osteonecrosis of the jaw (BRONJ) after exodontias. Thirty female rats were randomized into 2 groups, control and experimental. The experimental group received 2 intravenous injections of zoledronate (20 μg/kg).

Bone regeneration and docking site healing after bone transport distraction osteogenesis in the canine mandible.

Purpose: Bone transport distraction osteogenesis provides a promising alternative to traditional grafting techniques. However, existing bone transport distraction osteogenesis devices have many limitations. The purpose of this research was to test a new device, the mandibular bone transport reconstruction plate, in an animal model with comparable mandible size to humans and to histologically and mechanically examine the regenerate bone.

Three-dimensional evaluation of mandibular bone regenerated by bone transport distraction osteogenesis.

The purpose of this study was to evaluate the structure and material properties of native mandibular bone and those of early regenerate bone, produced by bone transport distraction osteogenesis. Ten adult foxhounds were divided into two groups of five animals each. In all animals, a 3- to 4-cm defect was created on one side of the mandible.

Malignant peripheral nerve sheath tumor of mandible.

Malignant peripheral nerve sheath tumor is a common tumor that rarely affects the head and neck region. The patient presented in this report is a teenage girl presented with a lesion in the right body of the mandible with severe disfigurement of the lower face. The lesion was first histopathologically diagnosed as embryonal rhabdomyosarcoma.

Submandibular gland and caries susceptibility in the obese Zucker rat.

Background: Obesity is a prevalent disorder characterized as marked insulin resistance and low grade inflammation. We tested the hypothesis that obesity upregulates inflammatory markers in the submandibular gland in association with derangements of its architecture and pre-disposition to caries in obese Zucker rats (OZR). We also examined the potential impact of chromium picolinate (Cr(Pic)3), a nutritional supplement suggested to improve glycemic control, on the aforementioned parameters.

Reconstruction of canine mandibular bone defects using a bone transport reconstruction plate.

Objectives: Reconstruction of mandibular segmental bone defects is a challenging task. This study tests a new device used for reconstructing mandibular defects based on the principle of bone transport distraction osteogenesis.

Methods: Thirteen beagle dogs were divided into control and experimental groups.

Reconstruction of large mandibular bone and soft-tissue defect using bone transport distraction osteogenesis.

Reconstruction of large anterior mandibular defects is a challenging task. The condition can become even more complex if primary reconstruction fails, leading to loss of the entire midline portion of the lower face with massive scarring of the remaining tissues. Bone transport distraction osteogenesis can provide a viable treatment option for these patients.