Orthodontic treatment of patient with maxillofacial fibrous dysplasia : a case report

Fibrous dysplasia is a benign skeletal disorder in which the normal bone and marrow are replaced by fibrous tissue and haphazardly distributed woven bone. The aim of this case report is to discuss the orthodontic treatment of a 13-year-old patient with fibrous dysplasia in the left maxilla. The patient had rotated maxillary second premolars, moderate crowding in both maxillary and mandibular arches with low maxillary frenal attachment. Orthodontic treatment was done with full fixed appliance and extraction of maxillary and mandibular third molars. Maxillary frenectomy and free gingival graft in mandibular anterior region were performed by a periodontist. The oral and maxillofacial surgery team monitored fibrous dysplasia in the left maxilla on a yearly interval. There is very limited information about orthodontic management of patients with craniofacial fibrous dysplasia. This case report discusses the orthodontic treatment and the importance of interdisciplinary approach in the management of patient with maxillofacial fibrous dysplasia

PhyloToAST: Bioinformatics Tools for Species-Level Analysis and Visualization of Complex Microbial Datasets

The 16S rRNA gene is widely used for taxonomic profiling of microbial ecosystems; and recent advances in sequencing chemistry have allowed extremely large numbers of sequences to be generated from minimal amounts of biological samples. Analysis speed and resolution of data to species-level taxa are two important factors in large-scale explorations of complex microbiomes using 16S sequencing. We present here new software, Phylogenetic Tools for Analysis of Species-level Taxa (PhyloToAST), that completely integrates with the QIIME pipeline to improve analysis speed, reduce primer bias (requiring two sequencing primers), enhance species-level analysis, and add new visualization tools. The code is free and open source, and can be accessed at http://phylotoast.org

The Large Zinc Finger Protein ZAS3 Is a Critical Modulator of Osteoclastogenesis

Mice deficient in the large zinc finger protein, ZAS3, show postnatal increase in bone mass suggesting that ZAS3 is critical in the regulation of bone homeostasis. Although ZAS3 has been shown to inhibit osteoblast differentiation, its role on osteoclastogenesis has not been determined. In this report we demonstrated the role of ZAS3 in bone resorption by examining the signaling mechanisms involved in osteoclastogenesis.Comparison of adult wild-type and ZAS3 knockout (ZAS3-/-) mice showed that ZAS3 deficiency led to thicker bones that are more resistant to mechanical fracture. Additionally, ZAS3-/- bones showed fewer osteoclasts and inefficient M-CSF/sRANKL-mediated osteoclastogenesis ex vivo. Utilizing RAW 264.7 pre-osteoclasts, we demonstrated that overexpression of ZAS3 promoted osteoclastogenesis and the expression of crucial osteoclastic molecules, including phospho-p38, c-Jun, NFATc1, TRAP and CTSK. Contrarily, ZAS3 silencing by siRNA inhibited osteoclastogenesis. Co-immunoprecipitation experiments demonstrated that ZAS3 associated with TRAF6, the major receptor associated molecule in RANK signaling. Furthermore, EMSA suggested that nuclear ZAS3 could regulate transcription by binding to gene regulatory elements.Collectively, the data suggested a novel role of ZAS3 as a positive regulator of osteoclast differentiation. ZAS3 deficiency caused increased bone mass, at least in part due to decreased osteoclast formation and bone resorption. These functions of ZAS3 were mediated via activation of multiple intracellular targets. In the cytoplasmic compartment, ZAS3 associated with TRAF6 to control NF-kB and MAP kinase signaling cascades. Nuclear ZAS3 acted as a transcriptional regulator for osteoclast-associated genes. Additionally, ZAS3 activated NFATc1 required for the integration of RANK signaling in the terminal differentiation of osteoclasts. Thus, ZAS3 was a crucial molecule in osteoclast differentiation, which might potentially serve as a target in the design of therapeutic interventions for the treatment of bone diseases related to increased osteoclast activity such as postmenopausal osteoporosis, Paget's disease, and rheumatoid arthritis

Viscoelastic Properties of Orthodontic Elastomers

Orthodontic elastics have been used to generate tooth moving forces for nearly one hundred and fifty years. Currently used elastic materials in orthodontics are made either from natural rubber or synthetic polymeric materials. The former, referred to as elastic or latex (cis-polyisoprene) bands are available in various dimensions. The synthetic polymeric materials were supplied initially in the form of modules and subsequently as versatile chains and are commonly referred to as orthodontic elastomers or simply as elastomers (Figure 1). In the following text, the terms, elastomer, elastomeric chains or orthodontic elastomers refer specifically to the synthetic polymeric materials used in orthodontics to generate tooth moving forces. Elastomers enjoy wide popularity in orthodontics. The orthodontist is particularly concerned with the force these elastomers can exert over the time period of their clinical use. To date, most of the research on these elastomeric chains has attempted to answer two questions. How much force can be generated by stretching these chains to distances that are required for tooth movement (e.g. canine retraction) and what is the rate of force-decay that occurs due to the stress relaxation in these orthodontic polymers. Both of these questions have direct clinical relevance and it is not surprising that most of the previous research has focused on these areas. lnspite of their popularity, elastomeric chains have certain drawbacks. Their mechanical properties are time and temperature dependent. These elastomers swell and slowly hydrolyze on prolonged contact with water. Also, they are susceptible to aging due to the influence of light, thermal and chemical factors in their environment. Little information is available on the viscoelastic properties of these materials. Evaluation of the basic material properties would complement the load­ extension and force-decay data that are presently available. Such additional information and characterization of these materials may be helpful in predicting the in vivo performance of these chains. Also, many different brands of elastomeric chains are available in the market. Some orthodontists have their own favorite brands of chains, those that work best for them. However, others use different brands interchangeably. It is unlikely that different brands would exert identical tooth moving forces. Manufacturers provide limited information about the nature of these elastomers and surprisingly few instructions regarding their desirable storage conditions and shelf life. The chemical structure and the manufacturing processes of these chains largely remains proprietary information. The main chemical compound in the chains is, however, believed to be a polyurethane. It would be desirable to determine the possible relationships between the molecular structure, manufacturing processes and the mechanical properties of these materials. The main goal of this investigation was to determine the viscoelastic and elastic properties of commercially available orthodontic elastomeric chains. A secondary goal was to obtain information from the manufacturers regarding the composition and recommendations for storage and use of these materials

Helping Dental Students Make Informed Decisions About Private Practice Employment Options in a Changing Landscape

According to the 2014 American Dental Education Association (ADEA) Survey of Dental School Seniors, 45.3% of new graduates planned to enter private practice immediately after graduation; of those, while 65% planned to become an associate dentist in a private practice, 28.3% intended to enter a corporate group practice—the only category that saw an increase over the previous year. Current trends indicate that the number of new graduates choosing to enter some form of private practice without further education will continue to remain high, due in large part to the need to repay educational debt. In light of these trends, the question that must be asked is whether dental schools are optimally preparing students to make informed decisions regarding future employment options in the changing dental practice landscape. This article argues that dental schools should review their curricula to ensure graduates are being prepared for this changing environment and the increased business pressures associated with dental practice. Important considerations in preparing dental students to be successful in the process of selecting a practice model are identified

The bones of adult <i>ZAS3</i> knockout mice have increased bone strength, thickness, and mineralization.

<p>(A) Biomechanical properties of femurs were evaluated by three-point bending test. Load to fracture (Fx) was significantly increased in both male and female <i>ZAS3−/−</i> mice compared to +/+ and +/− control mice (*, <i>p</i><0.05). (B) & (C) Micro-CT reconstruction images of femora of 4-month-old mice. Bar represents 1 mm. (D) Sagittal section of distal femora from 5-month-old mice stained with von Kossa's method plus MacNeal tetrachrome counterstain. Mineralized bone was stained black and collagen type 1 was stained light blue. Bar represents 1 mm. +/+ <i>ZAS3</i> WT mice, −/− <i>ZAS3</i> KO mice, and +/− heterozygous ZAS3 mice.</p

Molecular targets of ZAS3 in RANK signaling.

<p>Shown is a schematic diagram depicting the multiple targets of ZAS3 involved in the regulation of RANK signaling, important for osteoclastogenic differentiation and function. Binding of RANKL to RANK activates cytoplasmic ZAS3 that (i) induces expression of TRAF6 and association of ZAS3 and TRAF6 leading to the recruitment of TGF-β-activated kinase 1 (TAK1) binding protein 2/3 (TAB2/3) to polyubiquitinated TRAF6, which in turn activates TAB1/TAK1, inhibitor of NF-kB alpha (IkBα) kinase (IKK) complexes, and nuclear translocation of NF-kB p50/p65; (ii) Simultaneously, ZAS3 activates mitogen-activated protein kinases to activate the transcription factor AP-1 via phosphorylation of p38 and assembly of c-Jun/Fos; (iii) ZAS3 associates with c-Jun to activate AP1 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0017161#pone.0017161-Oukka2" target="_blank">[13]</a>; (iv) ZAS3 itself can act as a transcription factor, i.e., it translocates into the nucleus and binds to gene regulatory elements to activate transcription of osteoclast-associated genes, such as TRAP and CTSK, and probably NFATc1; and (iv) through the activation of NF-kB, ZAS3 also activates NFATc1 that is shown to integrate sRANKL signaling in the terminal differentiation of osteoclasts <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0017161#pone.0017161-Asagiri1" target="_blank">[30]</a>. Additionally, ZAS3 mobilizes intracellular calcium, probably through one of its target genes, the calcium binding protein <i>S100A4/mts1 </i><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0017161#pone.0017161-Hjelmsoe1" target="_blank">[4]</a>, to activate calcineurin causing the dephosphorylation and nuclear translocation of NFATc1. ZAS3 individually, or in a transcriptional complex in conjunction with NTAFc1 and NF-kB through association with AP-1 drives the transcription program for osteoclast differentiation. Important signaling molecules, transcription factors, or enzymes involved in RANK signaling whose expression levels or protein-protein interactions shown here to be regulated by ZAS3 are indicated with asterisks.</p