Direct, indirect, post-infection damages induced by coronavirus in the human body: an overview.

Background: Severe acute respiratory syndrome Coronavirus-2 invades the cells via ACE2 receptor and damages multiple organs of the human body. Understanding the pathological manifestation is mandatory to endure the rising post-infection sequel reported in patients with or without comorbidities. Materials and methods: Our descriptive review emphasises the direct, indirect and post-infection damages due to COVID-19. We have performed an electronic database search according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines with selective inclusion and exclusion criteria. Results: The included studies substantiated the extensive damages in the multiple organs due to direct and indirect consequences of COVID-19. After an apparent recovery, the prolonged presentation of the symptoms manifests as post-COVID that can be related with persisting viral antigens and dysregulated immune response. Conclusion: A few of the symptoms of respiratory, cardiovascular, and neuropsychiatric systems that persist or reappear as post-COVID manifestations. Vaccination and preventive programs will effectively reduce the prevalence but, the post-COVID, a multisystem manifestation, will be a significant tribulation to the medical profession. However, the issue can be managed by implementing public health programs, rehabilitation services, and telemedicine virtual supports to raise awareness and reduce panic.

Platelet-rich Plasma and Incidence of Alveolar Osteitis in High-risk Patients Undergoing Extractions of Mandibular Molars: A Case-control Study.

BACKGROUND: To evaluate the efficiency of platelet-rich plasma (PRP) on the incidence of alveolar osteitis (AO) in patients with potential risk factors for the development of AO. MATERIALS AND METHODS: This study was conducted in 150 patients visiting the outpatient department of oral and maxillofacial surgery. Patients with potential risk factors for the development of AO which included smokers, alcoholics, postmenopausal women, patients on oral contraceptives, pericoronitis, and bruxism were included for the study. Patients were randomly divided into two groups. Group A consisted of 75 patients in which PRP was placed in the socket after extraction. Group B consisted of 75 patients in which sockets were left for normal healing without the placement of PRP. The patients were assessed for pain and dry socket on the 3rd and 5th postoperative day. RESULTS: All the local signs and symptoms of inflammation were mild to moderate and subsided in normal course of time. Pain was less in Group A where the extraction sockets were treated with PRP. Soft-tissue healing was also statistically significant on the PRP treated site when compared to the other group where PRP was not placed into the socket after extraction. The incidence of AO among the patients who have the potential risk factor for the development of the same was significantly reduced in Group A. CONCLUSION: The study showed that autologous PRP is a biocompatible material and has significantly improved the process of soft-tissue healing, reduced pain, and decreased the incidence of AO in the extraction socket when treated with PRP.

Stem cells: An insight into the therapeutic aspects from medical and dental perspectives.

The recent advancements in the field of stem cell (SC) biology have increased the hope of achieving the definitive treatments for the diseases which are now considered incurable such as diabetes, Parkinson's disease and other chronic long standing conditions. To achieve this possibility, it is necessary to understand the basic concepts of SC biology to utilize in various advanced techniques of regenerative medicine including tissue engineering and gene therapy. This article highlights the types of SCs available and their therapeutic capacity in regenerative medical and dental fields.

Harvesting dental stem cells - Overview.

Dental stem cells have recently become one of the widely researched areas in dentistry. Ever since the identification of stem cells from various dental tissues like deciduous teeth, dental papilla, periodontal ligament and third molars, storing them for future use for various clinical applications was being explored. Dental stem cells were harvested and isolated using various techniques by different investigators and laboratories. This article explains the technical aspects of preparing the patient, atraumatic and aseptic removal of the tooth and its safe transportation and preservation for future expansion.

Odontogenic epithelial stem cells: hidden sources.

The ultimate goal of dental stem cell research is to construct a bioengineered tooth. Tooth formation occurs based on the well-organized reciprocal interaction of epithelial and mesenchymal cells. The dental mesenchymal stem cells are the best explored, but because the human odontogenic epithelium is lost after the completion of enamel formation, studies on these cells are scarce. The successful creation of a bioengineered tooth is achievable only when the odontogenic epithelium is reconstructed to produce a replica of natural enamel. This article discusses the untapped sources of odontogenic epithelial stem cells in humans, such as those present in the active dental lamina in postnatal life, in remnants of dental lamina (the gubernaculum cord), in the epithelial cell rests of Malassez, and in reduced enamel epithelium. The possible uses of these stem cells in regenerative medicine, not just for enamel formation, are discussed.

Cytomorphometric analysis of exfoliated cells in oral lichen planus.

BACKGROUND: Tumors are distinguished from normal tissues partly by their pronounced variability of cellular and nuclear dimensions. Therefore, such factors may be an indicator to assess whether the cells are malignant or not. Exfoliative cytology is a reliable tool in assessing such changes in the uterine cervix and has been used in the oral cavity also with success. The aims and objectives of the following study were to evaluate the malignant changes by assessing the quantitative parameters such as cytoplasmic diameter, cytoplasmic perimeter and cytoplasmic area (CD, CP, CA) and nuclear diameter, nuclear perimeter and nuclear area (ND, NP, NA) and cytoplasmic to nuclear ratio in the exfoliated cells of various subtypes of oral lichen planus (OLP) using cytomorphometry. MATERIALS AND METHODS: Oral exfoliated cells from nineteen cases of histologically proven OLP (1 atrophic, 13 reticular, 4 erosive and 1 plaque) and ten controls with healthy mucosa were taken and stained by Feulgen-Rossenback reaction and cytomorphometric analysis was performed using an image analysis software. The parameters taken into account were CD, CP, CA and ND, NP, NA. Furthermore CA/NA was calculated. The parameters were statistically analyzed using the t-test. RESULTS: Cytomorphometric analysis of all the parameters showed no significant difference between the control group and the reticular/plaque subtypes, whereas statistically significant (P < 0.05) differences was obtained between the control group and the atrophic/erosive subtypes group when compared using t-test. CONCLUSIONS: The cytomorphometric analysis of OLP shows that erosive/atrophic subtypes of OLP are at more risk and exfoliative cytology and cytomorphometry can be used as a tool to assess the malignant changes.

Molecular predictors in the early diagnosis of oral cancer.

Human beings are being subjected to a variety of disease processes, a majority of which can be cured. However, cancer remains an endangering disease that affects various body parts. Though cancers can be prevented by various therapeutic modalities, the patient survival and the prognosis are questionable, as they are detected at very late stages. The aim of improving the prognosis lies in an early detection of the cancer, which can be brought about by an analysis of the changes in the cellular biomolecules.

Estimation of age using aspartic acid racemisation in human dentin in Indian population.

AIM: The quest to identify an accurate method of age estimation, had lead to the evaluation of aspartic acid racemisation in hard tissues of the human remains using high performance liquid chromatography (HPLC). Our study is aimed at the applicability of the racemisation technique to use dentin as the sample to estimate the age in South Indian sub-population. MATERIALS AND METHODS: Thirty-six non-carious teeth from living individuals distributed among 6 age groups (6 each), sexes (18 each) and jaws (18 each) were analysed for dextro (d) and levo (l) forms of aspartic acid using high performance liquid chromatography (HPLC) technique and their racemisation ratio were calculated for each tooth sample. RESULTS: High correlation was obtained between the aspartic acid racemisation rates in dentin and age of the individual with an error limited to ±3 years. Racemisation rates in teeth did not significantly differ between the sexes or jaws. CONCLUSION: The d-aspartic acid accumulation in dentin is synchronous with the aging of an individual and can be used as an accurate method of age estimation in our population.

Expression of inducible nitric oxide synthase (iNOS) in oral precancer and oral squamous cell carcinoma: an immunohistochemical study.

AIMS: Prolonged production of the free radical, nitric oxide (NO) by the enzyme inducible nitric oxide synthase (iNOS) plays an important role in tumour progression by promoting angiogenesis, invasion and inducing mutation in tumour suppressor gene. The purpose of this study is to evaluate the expression and intensity of iNOS in normal oral mucosa, precancer and oral squamous cell carcinoma (OSCC). MATERIALS AND METHODS: An immunohistochemical study was performed using rabbit monoclonal antibody to iNOS on archival formalin fixed, paraffin embedded tissues of 5 normal oral mucosal samples, 10 Leukoplakia, 10 oral submucous fibrosis (OSMF) and 15 OSCC of different grades. RESULTS: A statistical significant difference was found between normal oral mucosa, precancer and OSCC in expression of iNOS (p value 0.0015). However, there was no statistically significant difference between the expressions of iNOS within premalignant groups (p value 0.5647) and histological sub-groups of OSCC (p value-0.5647). There was no statistically significant difference in the intensity of iNOS expression within the precancer group, OSCC sub-groups and between precancer and OSCC (p value-0.623). CONCLUSION: The orderly increase in the expression of iNOS from normal, through precancer, to OSCC suggests the essential role played by iNOS in epithelial transformation and tumour formation.