BST2 Mediates Osteoblast Differentiation via the BMP2 Signaling Pathway in Human Alveolar-Derived Bone Marrow Stromal Cells.

The molecular mechanisms controlling the differentiation of bone marrow stromal stem cells into osteoblasts remain largely unknown. In this study, we investigated whether bone marrow stromal antigen 2 (BST2) influences differentiation toward the osteoblasts lineage. BST2 mRNA expression in human alveolar-derived bone marrow stromal cells (hAD-BMSCs) increased during differentiation into osteoblasts.

Brief Report: Consecutive Alendronate Administration-Mediated Inhibition of Osteoclasts Improves Long-Term Engraftment Potential and Stress Resistance of HSCs.

Osteoclasts form a bone marrow (BM) cavity serving as a hematopoietic niche for the maintenance of hematopoietic stem cells (HSCs). However, the role of osteoclasts in the BM has been controversially reported and remains to be further understood. In the present study, we investigated how osteoclasts affect the modulation of hematopoietic stem/progenitor cells in the BM by administering bisphosphate alendronate (ALN) to B6 mice for 21 consecutive days to inhibit osteoclast activity.

Smad4 in osteoblasts exerts a differential impact on HSC fate depending on osteoblast maturation stage.

Osteoblasts (OBs) are indispensable for the maintenance of hematopoietic stem cells (HSCs) in the bone marrow microenvironment. Here we investigated how Smad4 modulates HSC fate at distinct stages of OB development. For this, we conditionally knocked out Smad4 in cells expressing type I collagen (Col1a1) and osteocalcin (OC), respectively.

TGF-β Signaling Regulates Cementum Formation through Osterix Expression.

TGF-β/BMPs have widely recognized roles in mammalian development, including in bone and tooth formation. To define the functional relevance of the autonomous requirement for TGF-β signaling in mouse tooth development, we analyzed osteocalcin-Cre mediated Tgfbr2 (OC(Cre)Tgfbr2(fl/fl)) conditional knockout mice, which lacks functional TGF-β receptor II (TβRII) in differentiating cementoblasts and cementocytes. Strikingly, OC(Cre)Tgfbr2(fl/fl) mutant mice exhibited a sharp reduction in cellular cementum mass with reduced matrix secretion and mineral apposition rates.

Testicular acid phosphatase induces odontoblast differentiation and mineralization.

Odontoblasts differentiate from dental mesenchyme during dentin formation and mineralization. However, the molecular mechanisms controlling odontoblast differentiation remain poorly understood. Here, we show that expression of testicular acid phosphatase (ACPT) is restricted in the early stage of odontoblast differentiation in proliferating dental mesenchymal cells and secretory odontoblasts.

Perilipin+ embryonic preadipocytes actively proliferate along growing vasculatures for adipose expansion.

Despite the growing interest in adipose tissue as a therapeutic target of metabolic diseases, the identity of adipocyte precursor cells (preadipocytes) and the formation of adipose tissue during embryonic development are still poorly understood. Here, we clarified the identity and dynamic processes of preadipocytes in mouse white adipose tissue during embryogenesis through direct examination, lineage tracing and culture systems. Surprisingly, we found that lipid-lacking but perilipin(+) or adiponectin(+) proliferating preadipocytes started to emerge at embryonic day 16.

Expedited Record Base Fabrication Using an Irreversible Hydrocolloid Cast.

The registration of a maxillomandibular relationship requires additional clinical and laboratory procedures when the mouth presents with loss of occlusal support. This procedure can be a challenge for a patient who needs urgent care or resides in a remote area. This article describes a procedure for expediting the mounting of a master cast for the fabrication of a maxillary immediate complete denture.

Gpr177-mediated Wnt Signaling Is Required for Secondary Palate Development.

Cleft palate represents one of the major congenital birth defects in humans. Despite the essential roles of ectodermal canonical Wnt and mesenchymal Wnt signaling in the secondary palate development, the function of mesenchymal canonical Wnt activity in secondary palate development remains elusive. Here we show that Gpr177, a highly conserved transmembrane protein essential for Wnt trafficking, is required for secondary palate development.

Disruption of Tgfbr2 in odontoblasts leads to aberrant pulp calcification.

Transforming growth factor β (TGF-β) signaling has been implicated in dentin formation and repair; however, the molecular mechanisms underlying dentin formation remain unclear. To address the role of TGF-β signaling in dentin formation, we analyzed odontoblast-specific Tgfbr2 conditional knockout mice. The mutant mice had aberrant teeth with thin dysplastic dentin and pulpal obliteration, similar to teeth from human patients with dentinogenesis imperfecta type II and dentin dysplasia.

Temporo-spatial requirement of Smad4 in dentin formation.

The TGF-β/BMP family plays an important role in multiple stages of tooth development. TGF-β/BMP signaling is required for odontoblast differentiation and dentin formation; however, the precise molecular mechanisms underlying dentin formation remain unclear. To address the role of TGF-β/BMP signaling in dentin formation, we analyzed mice in which Smad4, a key intracellular mediator of TGF-β/BMP signaling, was subjected to tissue-specific ablation under the control of Dspp, OC, or Col1a1 promoters.

Wntless regulates dentin apposition and root elongation in the mandibular molar.

Wnt signaling plays an essential role in the dental epithelium and mesenchyme during tooth morphogenesis. However, it remains unclear if Wnt ligands, produced from dental mesenchyme, are necessary for odontoblast differentiation and dentin formation. Here, we show that odontoblast-specific disruption of Wntless (Wls), a chaperon protein that regulates Wnt sorting and secretion, leads to severe defects in dentin formation and root elongation.

Osterix regulates tooth root formation in a site-specific manner.

Bone and dentin share similar biochemical compositions and physiological properties. Dentin, a major tooth component, is formed by odontoblasts; in contrast, bone is produced by osteoblasts. Osterix (Osx), a zinc finger-containing transcription factor, has been identified as an essential regulator of osteoblast differentiation and bone formation.

Impact of implant support on mandibular free-end base removable partial denture: theoretical study.

Objectives: This study investigated the impact of implant support on the development of shear force and bending moment in mandibular free-end base removable partial dentures (RPDs).

Material And Methods: Three theoretical test models of unilateral mandibular free-end base RPDs were constructed to represent the base of tooth replacement, as follows: Model 1: first and second molars (M1 and M2); Model 2: second premolar (P2), M1, and M2; and Model 3: first premolar (P1), P2, M1, and M2. The implant support located either at M1 or M2 sites.

Reattachment of a fractured fragment with relined fiber post using indirect technique: a case report.

Although fiber-reinforced posts have been widely used, they sometimes fail to obtain sufficient retention because of an extremely large canal space. To address this, several techniques have been introduced including relining of the fiber-reinforced posts. Here, we used a relined glass-fiber post to increase retention and fitness to the root canal in a crown reattachment case.

Effects of mineral trioxide aggregate mixed with hydration accelerators on osteoblastic differentiation.

Introduction: Despite good physical and biological properties, mineral trioxide aggregate (MTA) has a long setting time. A hydration accelerator could decrease the setting time of MTA. This study assessed the biocompatibility of MTA mixed with hydration accelerators (calcium chloride and low-dose citric acid) and investigated the effect of these materials on osteoblast differentiation.

Healing after horizontal root fractures: 3 cases with 2-year follow-up.

Among dental traumas, horizontal root fractures are relatively uncommon injuries. Proper initial management and periodical evaluation is essential for the successful treatment of a root-fractured tooth. If pulpal necrosis develops, endodontic treatment is indicated, exclusively for the coronal fragment.

Indirect method of base adaptation against supporting element of tooth root for a partial overdenture prosthesis.

The base of a partial overdenture prosthesis should be fitted intraorally against the supporting element of a tooth root. Chairside relining is a common method; however, an autopolymerizing acrylic resin presents high porosity when polymerized intraorally. This article describes an indirect method where an impression is made with a silicone occlusion registration material to create a replica of the supporting elements of the residual ridge and the tooth root in a high-viscosity polyvinyl siloxane impression material.

Intraosseous pseudocarcinomatous hyperplasia associated with chronic osteomyelitis of the mandible: report of two cases.

Pseudocarcinomatous hyperplasia (PH) is a marked proliferation of benign squamous epithelium lacking cytologic atypia and pleomorphism in response to chronic stimuli, such as inflammation, infection, irradiation, or an underlying neoplastic reaction. Intraosseous PH is a rare complication of chronic osteomyelitis and mimics squamous cell carcinoma and other squamous neoplasms. This report describes 2 cases of intraosseous PH arising in the mandible.

β-catenin is required in odontoblasts for tooth root formation.

The tooth root is an important part of the tooth that works together with the surrounding periodontium to maintain the tooth in the alveolar socket. The root develops after crown morphogenesis. While the molecular and cellular mechanisms of early tooth development and crown morphogenesis have been extensively studied, little is known about the molecular mechanisms controlling tooth root formation.

Col1a1-cre mediated activation of β-catenin leads to aberrant dento-alveolar complex formation.

Wnt/β-catenin signaling plays a critical role in bone formation and regeneration. Dentin and cementum share many similarities with bone in their biochemical compositions and biomechanical properties. Whether Wnt/β-catenin signaling is involved in the dento-alveolar complex formation is unknown.

Excessive Wnt/β-catenin signaling disturbs tooth-root formation.

Background And Objective: Wingless-type MMTV integration site family (Wnt)/β-catenin signaling plays an essential role in cellular differentiation and matrix formation during skeletal development. However, little is known about its role in tooth-root formation. In a previous study, we found excessive formation of dentin and cementum in mice with constitutive β-catenin stabilization in the dental mesenchyme.

Analysis of the embrasure dimensions between maxillary central incisors in relation to the topography of the interdental papilla.

Purpose: To analyze the dimensions of the embrasure space between the maxillary central incisors as potential factors influencing interdental papilla fill and height.

Methods: The embrasure dimensions between the maxillary central incisors of 100 subjects (40 females/60 males) were assessed with clinical, study model, and radiographic examinations. Variables of the complete and deficient papilla fill groups were compared.