An interdisciplinary approach to restore missing maxillary lateral incisor with Orthodontics and Implant Prosthodontics: A Case Report

Abstract The absence of the maxillary lateral incisors create an asthetic problem that can be managed with different treatment modalities. Comprehensive treatment planning is required to achieve a satisfactory result, keeping in mind the aesthetics, function and periodontal stability. An interdisciplinary treatment approach is beneficial and involves orthodontic closure of the space with maxillary canine substitution or space opening for single- tooth implants, bridges and tooth-supported restorations. The present case of a 21-year-old female dental student with agenesis of maxillary left lateral incisor with the presence of maxillary left canine in place of lateral incisor, and midline deviation. Treatment included space creation and placement of 3.3mm implant together with bone augmentation, immediate temporization and finally restored with porcelain crown after healing period of three months

Design and validation of a physiologically-adapted bioreactor for tissue engineering of the nucleus pulposus

A novel multi-axial bioreactor was designed and developed to deliver combinations of the following dynamic mechanical stimulation conditions: hydrostatic pressure, pulsatile perfusion flow and uniaxial compression in order to mimic in vivo conditions. This mechanical arrangement simultaneously allows triaxial stimulation and characterization of mechanical properties of samples, in particular simulating the conditions experienced by the nucleus pulposus in vivo. A series of initial experiments were performed on this prototype system using consistent, commercially-available, three dimensional scaffolds in combination with human dermal fibroblasts. Our results show that while such bioreactors hold much promise in tissue engineering of desired organs, achieving the right combination of mechanical stimuli and other conditions required in order to enhance the final properties of the cell-scaffold systems is challenging

Improving umbilical cord blood processing to increase total nucleated cell count yield and reduce cord input wastage by managing the consequences of input variation

Background aims: With the rising use of umbilical cord blood (UCB) as an alternative source of hematopoietic stem cells, storage inventories of UCB have grown, giving rise to genetically diverse inventories globally. In the absence of reliable markers such as CD34 or counts of colony-forming units, total nucleated cell (TNC) counts are often used as an indicator of potency, and transplant centers worldwide often select units with the largest counts of TNC. As a result, cord blood banks are driven to increase the quality of stored inventories by increasing the TNC count of products stored. However, these banks face challenges in recovering consistent levels of TNC with the use of the standard protocols of automated umbilical cord processing systems, particularly in the presence of input variation both of cord blood volume and TNC count, in which it is currently not possible to process larger but useable UCB units with consequent losses in TNC.Methods: This report addresses the challenge of recovering consistently high TNC yields in volume reduction by proposing and validating an alternative protocol capable of processing a larger range of units more reliably.Results: This work demonstrates improvements in plastic ware and tubing sets and in the recovery process protocol with consequent productivity gains in TNC yield and a reduction in standard deviation.Conclusions: This work could pave the way for cord blood banks to improve UCB processing and increase efficiency through higher yields and lower costs

COVID-19 pandemic, pregnancy care, perinatal outcomes in Eastern Myanmar and North-Western Thailand: a retrospective marginalised population cohort

Background: The COVID-19 pandemic disrupted routine health care and antenatal and birth services globally. The Shoklo Malaria Research Unit (SMRU) based at the Thailand-Myanmar border provides cross border antenatal care (ANC) and birth services to marginalised pregnant women. The border between the countries entered lockdown in March 2020 preventing cross-border access for women from Myanmar to Thailand. SMRU adapted by opening a new clinic during the COVID-19 pandemic in Myanmar. This study explored the impact of the COVID-19 pandemic and response on access to ANC and pregnancy outcomes for marginalised pregnant women in the border regions between Thailand and Myanmar. Methods: A retrospective review of medical records of all pregnancies delivered or followed at antenatal clinics of the SMRU from 2017 to the end of 2022. Logistic regression was done to compare the odds of maternal and neonatal outcomes between women who delivered pre-COVID (2017–2019) and women who delivered in the COVID-19 pandemic (2020–2022), grouped by reported country of residence: Thailand or Myanmar. Results: Between 2017 and the end of 2022, there were 13,865 (5,576 resident in Thailand and 8,276 in Myanmar) marginalised pregnant women who followed ANC or gave birth at SMRU clinics. Outcomes of pregnancy were known for 9,748 women with an EGA ≥ 28 weeks. Unknown outcome of pregnancy among women living in Thailand did not increase during the pandemic. However, there was a high (60%) but transient increase in unknown outcome of pregnancy for women with Myanmar residence in March 2020 following border closure and decreasing back to the baseline of 20–30% after establishment of a new clinic. Non-literate women were more likely to have an unknown outcome during the pandemic. There was no statistically significant increase in known stillbirths or maternal deaths during the COVID pandemic in this population but homebirth was over represented in maternal and perinatal mortality. Conclusion: Decreasing barriers to healthcare for marginalised pregnant women on the Thailand-Myanmar border by establishment of a new clinic was possible in response to sudden border closure during the COVID-19 pandemic and most likely preventing an increase in maternal and perinatal mortality

Design and validation of a scaffold library and algorithm for tissue engineering applications

A novel CAD system of structures based on convex polyhedron units has been created for use with Rapid Prototyping (RP) technology in tissue engineering applications. The prototype system is named the Computer Aided System for Tissue Scaffolds or CASTS.DOCTOR OF PHILOSOPHY (MPE

Web-based Decision Support System with Group Buying using Analytic Hierarchy Process

In electronic market places, group buying is seen as an effective form of electronic commerce. When buyers cooperate with each other, a seller can discount the price of a good. In existing group buying sites, each buyer preference may not be reflected effectively. This system implements a decision support system (DSS) for group buying based on buyer’s preferences. DSS is an interactive system that provides the user with easy access to decision models and data in order to support semi-structure and/or unstructured decision making task. This system is intended to develop a computerized system for some functions of house trading. The aim of this paper is to develop the web-based decisions support system for house selection using Analytical Hierarchical Process (AHP). The AHP appears to be a flexible decision making tool for multi-criteria problems such as selection of the best house

Polyvinylpyrrolidone-Based Bio-Ink Improves Cell Viability and Homogeneity during Drop-On-Demand Printing

Drop-on-demand (DOD) bioprinting has attracted huge attention for numerous biological applications due to its precise control over material volume and deposition pattern in a contactless printing approach. 3D bioprinting is still an emerging field and more work is required to improve the viability and homogeneity of printed cells during the printing process. Here, a general purpose bio-ink was developed using polyvinylpyrrolidone (PVP) macromolecules. Different PVP-based bio-inks (0%–3% w/v) were prepared and evaluated for their printability; the short-term and long-term viability of the printed cells were first investigated. The Z value of a bio-ink determines its printability; it is the inverse of the Ohnesorge number (Oh), which is the ratio between the Reynolds number and a square root of the Weber number, and is independent of the bio-ink velocity. The viability of printed cells is dependent on the Z values of the bio-inks; the results indicated that the cells can be printed without any significant impairment using a bio-ink with a threshold Z value of ≤9.30 (2% and 2.5% w/v). Next, the cell output was evaluated over a period of 30 min. The results indicated that PVP molecules mitigate the cell adhesion and sedimentation during the printing process; the 2.5% w/v PVP bio-ink demonstrated the most consistent cell output over a period of 30 min. Hence, PVP macromolecules can play a critical role in improving the cell viability and homogeneity during the bioprinting process.ASTAR (Agency for Sci., Tech. and Research, S’pore)Published versio

Potential of Bioprinted Films for Skin Tissue Engineering

Key roles of the healthy human skin are to prevent bacterial infection and excessive loss of water. However, such essential roles are compromised in patients with severe burns or chronic wounds. Synthetic materials such as petrolatum gauze backings and silicone membranes are commonly used in wound dressings to improve its mechanical properties and temporarily restore the role of the damaged skin. These synthetic materials are usually non-biodegradable and subsequent removal of such temporary wound dressings from the wound site is necessary. This necessitates the development of biodegradable films for skin tissue engineering. Although solvent casting is a simple fabrication technique for such films, properties such as mechanical strength and water transmission rate cannot be easily controlled via solvent casting technique. In this paper, a bioprinting approach will be explored for the fabrication of films for skin wound healing. The potential of such bioprinted films for skin tissue engineering is highlighted.ASTAR (Agency for Sci., Tech. and Research, S’pore)Published versio

Microvalve bioprinting of cellular droplets with high resolution and consistency

Cellular printing via bioprinting approaches holds tremendous potential in fabrication of tissues/organs. One of the attractive traits of bioprinting systems include precise control over the spatial deposition of multiple types of cells. Notably, cell sedimentation during printing process poses a huge challenge and the ability to maintain printing consistency over time is required to realize potential scale-up of bioprinting processes. To achieve successful controlled cellular deposition, it is ideal to ensure an improved printing output consistency and high dispensing efficiency at high printing resolution over time. In this work, we demonstrated that the use of polyvinylpyrrolidone 360KDa (PVP360) polymer in printing solution enhances the printing resolution and output consistency over a period of 30 minutes. We also determined the minimum cellular density required to achieve a high dispensing efficiency of > 95%.Published versio