In Vivo Analysis of Porous Bioactive Silicon Carbide Scaffold for Craniofacial Bone Augmentation.

BACKGROUND: Bone augmentation is a vital area of research because of its high clinical demand and the reported complications associated with the available biomaterials. Purpose: The study assess the role of decellurized skeletal muscle (DSM) when combined with synthesized porous bioactive silicon carbide (SiC) ceramic and evaluated its ability to augment bone calvaria in a rat model. MATERIAL AND METHODS: Eighteen rats were divided into 2 groups; group 1 (n=9), SiC discs (10 × 0.2 mm) pre-treated with 20% NaOH were placed as an onlay grafts on calvarial bone. Meanwhile, in group 2 (n=9), SiC discs pre-treated with 20% NaOH (10 × 0.2 mm) were covered with DSM. After 12 weeks, the grafted tissues were harvested and examined using cone-beam computed tomography, mechanical testing, and histologic analysis. RESULTS: Cone-beam computed tomography for group 2 showed more radio-opacity for the remnant of SiC compared with native bone. The surface area and volume of radio-opacity were 2.48 mm2 ± 1.6 and 14.9 ± 7.8 mm3, respectively. The estimated quantitative average surface area of the radio-opacity for group 1 and volume were 2.55 mm2 ± (Sd=3.7) and 11.25 ± (Sd=8.9), respectively. Mechanically, comparable values of the flexural strength and statistically significant higher modulus of elasticity of calvaria in group 1 compared with group 2 and control (P<0.001). Histologically, group 2 region of woven bone was seen close to the lamellar bone (native bone), and there was immature bone present near the implanted SiC. CONCLUSION: The tested construct made of SiC/DSM has potential to osteointegrate into native bone, making it a suitable material for bone augmentation.

The accuracy of soft tissue movement using virtual planning for non-syndromic facial asymmetry cases-a systematic review.

The 3D prediction of post-operative changes is an inevitable tool for the surgical correction of facial asymmetry. The objective is to execute an evidence-based review answering the following question. Does the 3D virtual prediction planning draw reliable and accurate results in the surgical outcome related to the soft tissues of the face in facial asymmetry? This systematic review of the literature is based on the 3D soft tissue prediction planning of facial asymmetry correction to draw conclusions on the reliability and accuracy of these methods in the surgical outcome related to the soft tissues of the face. PubMed, Web of Science, Cochrane, and Ovid databases were adopted for the literature search. Studies published between years 2000 and 2020, aimed at the assessment of soft tissue predictions using software prediction packages for facial asymmetry, were selected. The Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) was applied. Quadas-2 tool was used for the qualitative evaluation of selected studies. Initial search yielded 248 articles. Twenty articles fulfilled the inclusion and exclusion criteria and selected for qualitative analysis. Finally, 12 articles were selected for quantitative analysis. The results indicate 3D imaging prediction methods provided more accurate information with less distortion for soft tissue prediction regardless of various softwares currently available. The prediction of soft tissue accuracy in facial asymmetry was less accurate in lower face regardless of the type of surgery for facial asymmetry. The mean prediction error was less than 2 mm.

Assessment of novel surgical procedures using decellularised muscle and bioactive ceramic: a histological analysis.

Tissue regeneration and neovascularisation in cases of major bone loss is a challenge in maxillofacial surgery. The hypothesis of the present study is that the addition of resorbable bioactive ceramic Silica Calcium Phosphate Cement (SCPC) to Declluraized Muscle Scaffold (DSM) can expedite bone formation and maturation. Two surgical defect models were created in 18 nude transgenic mice. Group 1(n = 6), with a 2-mm decortication calvarial defect, was treated with a DSM/SCPC sheet over the corticated bone as an onlay then seeded with human Mesenchymal Stromal Cells hMSC in situ. In Group 2 (n = 6), a critical size (4 mm) calvarial defect was made and grafted with DSM/SCPC/in situ human bone marrow stromal cells (hMSCs). The control groups included Group 3 (n = 3) animals, with a 2-mm decortication defect treated with an onlay DSM sheet, and Group 4 (n = 3) animals, treated with critical size defect grafted with plain DSM. After 8 weeks, bone regeneration in various groups was evaluated using histology, immunohistochemistry and histomorphometry. New bone formation and maturation was superior in groups treated with DSM/SCPC/hMSC. The DMS/SCPC scaffold has the ability to augment and induce bone regeneration and neovascularisation in cases of major bone resorption and critical size defects.

A New Procedure in Bone Engineering Using Induced Adipose Tissue.

Background: Osteoporosis is associated with a metabolic imbalance between adipogenesis and osteogenesis. We hypothesized that implanting a carrier for differentiated stem cells and signaling molecules inside adipose tissues could be used to enable transdifferentiation between cells, upregulate osteogenesis, and support bone formation, which may regain the balance between osteogenesis and adipogenesis. Methodology: A CL1 human mesenchymal stem cell line was grown in an osteogenic medium to differentiate into osteoblasts, and the differentiated cells were then exposed to an adipogenic medium to stimulate differentiation into adipocytes. Osteogenic and adipogenic differentiation were confirmed by the following assays: alkaline phosphatase staining, Nile red Staining, and quantitative real-time polymerase chain reaction (qPCR). The ratio of adipocytes to osteocytes for both cases was calculated. To evaluate bone induction in vivo, a calcium sulfate/hydroxyapatite cement was prepared in a syringe and then seeded with 106 cells/mL of rat bone marrow stromal cells (rMSCs) and covered with 1 mL of tissue culture media containing 0.1 mg of bone morphogenetic protein 7 (BMP-7). The construct was injected into the abdominal fat tissue of 10 male Sprague-Dawley rats. Results: The conversion of osteocytes to adipocytes was 20-fold greater than the reverse conversion, and the area of bone regeneration was 15.7 ± 3.7%, the area of adipose tissue was 65.8 ± 13.1%, and the area of fibrous tissue was 18.3 ± 7.8%. Conclusion: Adipogenic interconversion and associated bone formation demonstrate the potential of a new therapy for balancing osteogenesis and adipogenesis.

Gossypiboma during orthognathic surgery: A case report.

INTRODUCTION: Dislodgment of nasopharyngeal temperature probes and/or unretrieved device fragments (UDFs) or gossypibome at a patient's hypopharynx is rare complication after orthognathic surgery that may occur as a result of surgical manipulation or may be a consequence of factors related to the insertion and handling of the probe after extubation. However, the exact mechanism of this complication is unknown. To the best of our knowledge, this is the 1st reported case of a missing temperature probe after orthognathic surgery. CASE PRESENTATION: We report the case of a patient who suffered from dislodgment of a 12-cm temperature probe after orthognathic surgery. The surgery was uneventful. At the end of the surgery, the probe was believed to have been completely removed from the nasal cavity. The nasopharyngeal cavity was visually inspected while the patient was still under anaesthesia and the trachea was still intubated. Extubation was successful, and the patient was moved to the recovery area. The patient was discharged from the hospital one day after resuming an oral fluid diet. At the follow-up visit on the 4th postoperative day, the patient presented with mild symptoms of a sore throat and cough. At the follow-up visit in the 3rd postoperative week, the patient reported one episode of vomiting and severe coughing, and the patient ultimately retrieved the 12-cm temperature probe from her mouth. DISCUSSION: After conducting a systematic literature review, we discuss surgical cases involving UDFs or gossypiboma. We also describe changes in our clinical practice after this event, and we envision that these modifications will have a positive influence on patient care. We believe that alternative routes for inserting temperature probes with covers would be suitable for orthognathic surgery. CONCLUSION: Vigilance should be maintained during patient extubation by both teams (surgeons and anaesthetists) to assure that part of the probe always remains visible outside the oral/nasal cavity as well as complete removal of the device to avoid this life-threating complication.

The relation between teeth loss and cognitive decline among Saudi population in the city of Riyadh: A pilot study.

BACKGROUND: Teeth are necessary for sensory input to the brain during the chewing process, but how the decrease in this sensory input, due to loss of teeth, may cause weak memory and lead to cognitive decline is not well understood. This pilot public survey aiming to assess the correlation between the number of missing teeth, periodontal disease, and cognitive skill in the city of Riyadh. MATERIAL& METHODS: A multicenter cross-sectional survey, targeting geriatric population aged ≥60 years, was performed in Riyadh City, Saudi Arabia. The Montreal Cognitive Assessment (MoCA) was conducted to all participants to assess their cognitive function. Assessment of oral health status was carried out, including the number of present dentation and their periodontal status. Community periodontal-index (CPI) was used to assess the periodontal condition. The primary variables were number of missing teeth, periodontal disease and MoCA test scores. Chi-square test and Pearson's correlation coefficients were computed and the significant P- value was set at <0.05. RESULTS: Of 95 participants, overall, 57 (60%) and 38 (40%) were male and female, respectively, with a mean age of 65.67 ±â€¯6.32 years. Females showed more significant cognitive decline than males (P < 0.001). Cognitive decline was significantly high in participants with low educational level 19 (95%), unemployment 41 (79%), and lower income people 26 (79%), while being cognitive intact was significantly higher in highly educated 13 (87%), retired 21 (62%), and higher income people 28 (74%) at (P < 0.001). An advanced age and greater number of missing teeth are associated with lower MoCA test scores. No statistical significant correlation with regard to periodontal disease and MoCA test scores. CONCLUSION: Based on the preliminary data, positive correlation was confirmed when the number of missing teeth and cognitive skill were assessed. Therefore, larger, multi-center regional surveys are needed to investigate further this relationship.

The Association Between Coffee Consumption and Local Anesthesia Failure: Social Beliefs and Scientific Evidence.

Introduction In our clinical practice, we have encountered patients who reported the failure of local anesthesia due to excessive coffee consumption and required higher-than-normal doses of local anesthesia. Therefore, our study aimed to assess the awareness and knowledge of coffee consumption, its effect on local anesthesia, and the available scientific evidence among the public, patients, and clinicians in dental practice.  Material and Methods A cross-sectional survey with two sets of questionnaires was designed based on the Likert scale. A 5-point scale was used to assess agreement and frequency. Yes/no and open-ended questions were used for the assessment. Questionnaires were distributed among the clinicians, patients, and the public. Data were analyzed with descriptive linear statistics. Results Of the 430 responses provided by patients and the general public, more than 40% believed that the local anesthetic failure was caused by excessive coffee consumption. Among the 235 responses provided by the clinicians, 65% of the clinicians reported encountering patients with local anesthesia failure and believed it could be due to excessive coffee consumption. However, only 9% of the clinicians were aware of scientific evidence regarding the effect of coffee consumption on local anesthesia failure.  Conclusion Surprisingly, the majority of clinicians believed that caffeine had an effect on the reduction of local anesthesia; however, only a few of them had scientific knowledge. The available scientific evidence relates that caffeine can influence cognitive performance by increasing alertness, as well as sleep deprivation causing stress and anxiety, which partially explains the local anesthetic failure among coffee consumers. Therefore, a stress reduction protocol should be a routine daily practice for a dentist to reduce the failure rate of local anesthesia.

A Novel assessment tool monitoring the level of patient anxiety during third molar surgery procedure.

The authors hypothesized that an audio-visual presentation providing information regarding the removal of an impacted mandibular third molar would reduce patient anxiety. AIM& OBJECTIVES: A clinical trial was performed to assess the level of patient anxiety during third molar surgery by using a new induction program and comparing the results amongst two groups that were the verbally informed and the audio-visual informed groups. MATERIALS AND METHODS: the clinical trial included the patients who required surgical removal of an impacted third molar and fulfilled the predetermined criteria. The patients were divided into two groups - group 1 (no. = 20) the audio visual informed group and group 2(no. = 20) the verbally informed group. For both the groups the HR was recorded beat by beat using HR sensor (polar H1 UK) connected to an ActiGraph WGT3X- 3T USA. Also the modified dental analogue scale(MDAS) was used to subjectively record the anxiety during the surgery. RESULTS: The HR reading were statistically significant for the following surgical stages; drilling, suturing and upon leaving the clinic. The audio-visual informed group had lower self-reported anxiety scores than did the verbally informed group. CONCLUSION: These results suggested that providing an audio-visual presentation about the surgical procedures in our routine clinical practice could aid in alleviating anxiety which would thereby reduce surgical complications.

Synthesis of chemically modified BisGMA analog with low viscosity and potential physical and biological properties for dental resin composite.

OBJECTIVES: The currently available commercial dental resin composites have limitations in use owing to the high viscosity and water sorption of Bisphenol A glycidyl methacrylate (BisGMA). The objective of this study was to obtain a BisGMA analog with reduced viscosity and hydrophilicity for potential use as an alternative to BisGMA in dental resin composites. METHODS: The targeted chlorinated BisGMA (Cl-BisGMA) monomer was synthesized via the Appel reaction. The structural modification was confirmed via 1H- and 13C nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, and mass spectrometry. Five resin mixtures (70:30wt.%: F1=BisGMA/TEGDMA; F2=Cl-BisGMA/TEGDMA; F3=Cl-BisGMA only; F4=Cl-BisGMA/BisGMA; F5 contained 15% TEGDMA with equal amounts of BisGMA and Cl-BisGMA) were prepared. The viscosity, degree of double-bond conversion (DC), water sorption (WSP), and solubility (WSL) were tested. Cell viability and live/dead assays, as well as cell attachment and morphology assessments, were applied for cytotoxicity evaluation. RESULTS: Cl-BisGMA was successfully synthesized with the viscosity reduced to 7.22 (Pas) compared to BisGMA (909.93,Pas). Interestingly, the DC of the F2 resin was the highest (70.6%). By the addition of equivalence concentration of Cl-BisGMA instead of BisGMA, the WSP was decreased from 2.95% (F1) to 0.41% (F2) with no significant change in WSL. However, the WSL increased with high Cl-BisGMA content. Biological tests revealed that all the resins were biocompatible during CL1 incubation. SIGNIFICANCE: The experimental resins based on Cl-BisGMA exhibited improved properties compared with the control samples, e.g., biocompatibility and lower viscosity, indicating that Cl-BisGMA can be considered as a potential monomer for application in dental resin composites.

Porous Polyethylene Coated with Functionalized Hydroxyapatite Particles as a Bone Reconstruction Material.

In this study, porous polyethylene scaffolds were examined as bone substitutes in vitro and in vivo in critical-sized calvarial bone defects in transgenic Sprague-Dawley rats. A microscopic examination revealed that the pores appeared to be interconnected across the material, making them suitable for cell growth. The creep recovery behavior of porous polyethylene at different loads indicated that the creep strain had two main portions. In both portions, strain increased with increased applied load and temperature. In terms of the thermographic behavior of the material, remarkable changes in melting temperature and heat fusion were revealed with increased the heating rates. The tensile strength results showed that the material was sensitive to the strain rate and that there was adequate mechanical strength to support cell growth. The in vitro cell culture results showed that human bone marrow mesenchymal stem cells attached to the porous polyethylene scaffold. Calcium sulfate-hydroxyapatite (CS-HA) coating of the scaffold not only improved attachment but also increased the proliferation of human bone marrow mesenchymal stem cells. In vivo, histological analysis showed that the study groups had active bone remodeling at the border of the defect. Bone regeneration at the border was also evident, which confirmed that the polyethylene acted as an osteoconductive bone graft. Furthermore, bone formation inside the pores of the coated polyethylene was also noted, which would enhance the process of osteointegration.

Assessment of cellular viability on calcium sulphate/hydroxyapatite injectable scaffolds.

Cements for maxillofacial reconstruction of jaw defects through calcification of rotated muscle have been tested. The objective of this study was to investigate the visibility of loading of two types of commercially available cements, Cerament(™) Spine Support and Cerament Bone Void Filler with mesenchymal cells and cytokines (bone morphogenetic protein) to act as a biomimetic scaffolding for future clinical application. Determination of basic biocompatibility (cell viability) using methyl thiazolyl tetrazolium and live/dead assay was carried out using MG-63 cells at various time points. Next, in order to inform potential subsequent in vivo experiments, a collagen tissue mimic was used for characterization of rabbit mesenchymal stromal cells using immunofluorescent cytoskeleton staining, and simultaneous and then sequential injection of Cerament Spine Support cement and cells into collagen gels. Results indicated that Cerament Spine Support was more biocompatible and that sequential injection of cement and then rabbit mesenchymal stromal cells into the tissue mimics is an optimal approach for clinical applications.