Masseter Vestibular evoked myogenic potentials: A new tool to assess the vestibulomasseteric reflex pathway.

Purpose: This review article provides the readers with an in-depth insight in understanding and interpreting various research literatures on the masseter vestibular evoked myogenic potentials (mVEMP). The article also reviews the contemporary researches involving the clinical applications of the mVEMP. Conclusions: Masseter VEMP is an evolving yet clinically promising neuro-otology test tool that has recently gained more research interest and is considered an additional tool to diagnose various vestibular disorders. Masseter VEMP assesses the functional integrity of the acoustic-masseteric and vestibulo-masseteric reflex pathways. The mVEMP could be used as a complementary test to evaluate the same peripheral generator as the cervical VEMP but a different central pathway i.e., vestibulo-trigeminal pathway. Various research studies that have experimented on parameters such as the effect of different electrode montages (zygomatic vs mandibular configurations), stimulation rates, filter settings and stimuli used to evoke mVEMP have been discussed in this article that could assist in the optimization of a comprehensive clinical protocol. The latency and the amplitude of mVEMP waveforms serve as significant parameters in differentiating normals from those of the clinical populations. Along with the cVEMPs and oVEMPs, mVEMP might help diagnose brainstem lesions in REM Sleep behaviour disorders, Multiple Sclerosis and Parkinson's disease. However, further studies are required to probe in this area of research.

Polycaprolactone/graphene oxide/acellular matrix nanofibrous scaffolds with antioxidant and promyelinating features for the treatment of peripheral demyelinating diseases.

Peripheral demyelinating diseases entail damage to axons and Schwann cells in the peripheral nervous system. Because of poor prognosis and lack of a cure, this group of diseases has a global impact. The primary underlying cause of these diseases involves the inability of Schwann cells to remyelinate the damaged insulating myelin around axons, resulting in neuronal death over time. In the past decade, extensive research has been directed in the direction of Schwann cells focusing on their physiological and neuroprotective effects on the neurons in the peripheral nervous system. One cause of dysregulation in the remyelinating function of Schwann cells has been associated with oxidative stress. Tissue-engineered biodegradable scaffolds that can stimulate remyelination response in Schwann cells have been proposed as a potential treatment strategy for peripheral demyelinating diseases. However, strategies developed to date primarily focussed on either remyelination or oxidative stress in isolation. Here, we have developed a multifunctional nanofibrous scaffold with material and biochemical cues to tackle both remyelination and oxidative stress in one matrix. We developed a nanofibrous scaffold using polycaprolactone (PCL) as a foundation loaded with antioxidant graphene oxide (GO) and coated this bioscaffold with Schwann cell acellular matrix. In vitro studies revealed both antioxidant and remyelination properties of the developed bioscaffold. Based on the results, the developed multifunctional bioscaffold approach can be a promising biomaterial approach for treating demyelinating diseases.

Schwann cell-matrix coated PCL-MWCNT multifunctional nanofibrous scaffolds for neural regeneration.

Nerve tissue engineering aims to create scaffolds that promote nerve regeneration in the damaged peripheral nervous system. However, there remain some challenges in the construction of scaffolds in terms of mechanical properties and cellular behaviour. The present work aims to develop multifunctional implantable nanofibrous scaffolds for nerve regeneration. Using electrospinning, nanofibrous neat polycaprolactone (PCL) and PCL/multiwalled carbon nanotubes (PCL-MWCNT) composite scaffolds were prepared in random and aligned morphology. Schwann cells and their secreted biochemical factors are responsible for neuronal survival in the peripheral nervous system. Therefore, the acellular matrix of Schwann cells was spin-coated on the PCL-MWCNT scaffolds to aid nerve regeneration. Physicochemical and mechanical properties, and the in vitro cellular response of the developed nanofibrous were investigated. We observed no significant change in fibre diameter between neat PCL and PCL-MWCNT scaffolds regardless of the morphology. However, the inclusion of MWCNT reduced the mechanical strength of nanocomposite scaffolds compared to neat PCL. In vitro study revealed biocompatibility of the developed scaffolds both with and without an acellular matrix. Gene expression study revealed a significant increase in peripheral myelin protein (PMP22) expression on acellular matrix-coated PCL-MWCNT scaffolds compared to neat PCL counterparts. Overall, the results suggested Schwann cell matrix-coated PCL-MWCNT nanofibers as a promising conduit for peripheral nerve regeneration.

VOR gain of lateral semicircular canal using video head impulse test in acute unilateral vestibular hypofunction: A systematic review.

Introduction: Acute unilateral vestibular hypofunction is characterized by sudden onset of vertigo or dizziness, vomiting/nausea, gait instability, and nystagmus. This is commonly described as an acute vestibular syndrome and usually attributed to vestibular neuritis; however, up to 25% of acute vestibular syndrome is caused by a stroke of posterior circulations. The video head impulse test is a recent tool in the vestibular test battery that assesses the vestibule-ocular reflex by measuring the VOR gain and recording overt and covert saccades, these findings have been found to be helpful in the diagnosis of various vestibular disorders. Method: A literature search was conducted in databases, including PubMed Central, PubMed, and Web of Science. All the articles that define video head impulse test (vHIT), acute vestibular hypofunction, and vestibular neuritis were considered for the preliminary search. No limits were placed on the date of publication. The searches were limited to studies with full-text availability, published in English, and including human subjects. Search words such as "head impulse test," "video head impulse test," "vestibular ocular reflex," "acute vestibular syndrome," "acute vestibular hypofunction," "vestibular neuritis," and "vHIT in central vestibular disorders" were entered into different databases in different combinations using boolean operators such as AND, OR, and NOT. Results: Searches across different databases, including Web of Science, PubMed Central, and PubMed, resulted in a total of 1,790 articles. Title screening was done for all the articles. Out of the 1,790 articles, we found that 245 articles were related to vestibular hypofunction i.e., 1,545 articles were removed at this stage. A further 56 duplicate articles were removed. This led to a final screening of 189 articles. The exclusion criteria included unavailability of full text, studies reported in languages other than English, case reports, reviews, and articles including participants having other comorbid conditions. This final screening led to 133 articles being excluded, which led to the full-text screening of 56 articles. After screening the full-text articles as per the eligibility criteria, 21 articles were found to be eligible for the systematic review. Among the remaining studies, six articles were excluded due to different specific reasons. A total of 15 articles were included in this systematic review. The mean VOR gain for the patients with vestibular neuritis was 0.48 ± 0.14 for the ipsilesional ear, whereas the mean VOR gain was > 0.80 in the contralesional ear for all the patients with acute vestibular neuritis. In patients with PICA lesions, the VOR gain for the ipsilesional ear was 0.90 (range 0.87-0.94) and for the contralesional ear was 0.88 (range 0.84-0.93). In patients with AICA lesions, the mean VOR gain was variable. Based on the above mean VOR gain findings, the authors propose the following adjective description scale of VOR of the lateral canal using vHIT: normal VOR gain above 0.80, mild VOR gain loss for 0.70-0.79, moderate loss for 0.69-0.4, severe loss for 0.39-0.2, and profound loss for < 0.2.

Prevalence of eight putative periodontal pathogens in atherosclerotic plaque of coronary artery disease patients and comparing them with noncardiac subjects: A case-control study.

BACKGROUND: The study was aimed to assess the prevalence of periodontal pathogens namely Tannerella forsythia (T.f), Campylobacter rectus (C.r), Eikenella corrodens (E.c), Porphyromonas gingivalis (P.g), Treponema denticola (T.d), Prevotella nigrescens (P.n) ,Aggregatibacter actinomycetemcomitans (A.a), P.g (fi mA gene) and Prevotella intermedia (P.i), in the subgingival and the atheromatous plaque of patients with coronary artery disease (CAD), and comparing them with the noncardiac subjects thereby indicating the role of periodontal pathogenic bacteria in the progression of atherosclerosis in south Indian population. MATERIALS AND METHODS: 51 cardiac and non cardiac subjects within the age group of 40-80 years,who met the eligibility criteria, were selected and categorized as the experimental and control group respectively. Total number of teeth was recorded, and oral hygiene was evaluated using Plaque Index and Oral Hygiene Index (OHI). Periodontal pocket depth and clinical attachment level were also assessed as a part of periodontal examination. Subgingival plaque samples were collected with the help of with Gracey's curette in both the groups. In experimental group, biopsy was obtained from the atherosclerotic plaque during Coronary artery bypass grafting CABG procedure. Both, subgingival and the coronary atherosclerotic plaque samples were subjected to polymerase chain reaction (PCR) analysis for identification of the periodontal bacteria. STATISTICAL ANALYSIS: Mean, standard deviation and test of significance of quantitative variables such as periodontal parameters were compared between experimental group and control group. Kappa measures of agreement was done to analyze the relationship between the presence/absence of microorganisms in the subgingival and atherosclerotic plaque samples in the experimental group. RESULTS: The mean Plaque Index, Gingival Index, Russel's Periodontal Index, OHI, clinical attachment level, Pocket Depth Index was statistically significant in both the groups. Association of T.f, E.c, C.r, P.g, P.g (fi mA), T.d, P.i, P.n was significantly associated. A.a was absent in the control group, whereas only one patient in the experimental group was positive for the bacteria. Kappa analysis showed the significant association of periodontal bacteria T.f, C.r, P.g, P.g (fi mA), P.i and P.n in subgingival plaque and atherosclerotic plaque of the same patients of the experimental group. CONCLUSION: It is concluded that CAD subjects had higher prevalence of periodontal pathogens in subgingival biofilms as compared to the non cardiac subjects. Further, the number of bacteria was significantly associated between the subgingival and atherosclerotic plaques of the cardiac patients in south Indian population.

Diagnostic imaging for dental implant therapy.

Dental implant is a device made of alloplastic (foreign) material implanted into the jaw bone beneath the mucosal layer to support a fixed or removable dental prosthesis. Dental implants are gaining immense popularity and wide acceptance because they not only replace lost teeth but also provide permanent restorations that do not interfere with oral function or speech or compromise the self-esteem of a patient. Appropriate treatment planning for replacement of lost teeth is required and imaging plays a pivotal role to ensure a satisfactory outcome. The development of pre-surgical imaging techniques and surgical templates helps the dentist place the implants with relative ease. This article focuses on various types of imaging modalities that have a pivotal role in implant therapy.

Estimation of salivary neopterin in chronic periodontitis.

BACKGROUND: Periodontal diseases are the most common bacterial infection predominantly associated with Gram-negative microorganisms that exist in the subgingival biofilm. Analysis of saliva provides a noninvasive means of evaluating the role of the host response in periodontal disease. Though salivary enzymes can be used as the biomarkers, neopterin has been recently used as one of the important diagnostic tools in the field of periodontics. Hence, we aimed to identify the neopterin levels in unsimulated saliva from the chronic periodontitis patients and compare them with the periodontally healthy subjects. MATERIALS AND METHODS: Twenty subjects participated in the study and were categorized as the experimental group (chronic periodontitis patients) and control groups (healthy subjects). Unstimulated saliva samples were collected from both the groups for neopterin estimation. Neopterin in saliva was estimated using Shimadzu High Performance Liquid Chromatography with LC-20AD pump system, equipped with RF-10 AXL fluorescence detector. STATISTICAL ANALYSIS USED: Data were expressed as mean±SD and analyzed using GraphPad Prism version 6.0 (California, USA). Statistical analysis was done by Student's t-test. RESULTS: The neopterin level in unstimulated saliva was found to be higher in the experimental group than the control group with P≤0.05. CONCLUSIONS: The chronic periodontitis patients showed higher neopterin level in unstimulated saliva as compared to control. Hence, neopterin can be used as a potential biomarker for identification of the periodontal disease in its initial stage can help in preventing the disease progression.