Diseases Of Oral Cavity Research Articles

FOCUS ON HEALTH BENEFITS OF TAMBUL SEVAN VIDHI AS DINCHARYA UPAKRAMA - A LITERATURE REVIEW

In Ayurveda classics, there is a detailed explanation of what a person should practice from getting up early in the morning to sleeping at night under dincharya upakrama. Tambul Sevan (chewing betel leaf) is described as one of the dincharya upakram i.e., daily regimen. Tambul Sevan means chewing betel leaf mixed with betel nut and other aromatic herbs. Tambul Sevan is an important social component. In Indian tradition, Tambul or paan has been consumed from vedic era that is 5000 years ago. But nowadays the traditional betel leaf and betel nuts are replaced by tobacco and other masala paan. Therefore, the whole concept of Tambul Sevan and its usefulness has been changed. Now there is a need to understand what Tambul Sevan Vidhi is. Ayurveda says Tambul Sevan maintains good oral hygiene and good taste of mouth, it also prevents bad odour and other oral cavity diseases. Tambul Sevan maintains agni (digestive fire) at its samya avastha (normal condition), so it is said to be consumed at end of the meal i.e., bhojananate tambul sevan. Here, this review article highlights the traditional way of Tambul Sevan Vidhi and its health benefits briefly. Keywords: Tambul, Tambul Sevan Vidhi, betel leaf, dincharya, health benefits.

MUKHA KRIYAKALPA - PROCEDURES FOR PREVENTION AND MANAGEMENT OF ORAL CAVITY DISORDERS

Mukha (oral cavity) is considered as a gateway for the alimentary canal, health of the oral cavity reflects the body health as healthy oral cavity aids in proper digestion of the food consumed. The oral cavity also takes part in bodi- ly functions like respiration and speech. It also contributes to the beauty and confidence of an individual. Mukha is comprised of Osta (lips), Dantamula (Gums), Danta (Tooth), Jinhva (Tongue), Taalu (Palate), Gala (Throat). Since the Oral cavity is constantly exposed to the external environment, there are more chances of trauma and infections. Hence to avoid the chances of oral cavity diseases it is very important to maintain good oral hygiene. Kriyakalpa is the therapeutic procedure applied locally and are considered under bahirparimarjana chikitsa. Ka- vala, Gandusha and Pratisarana are kriyakalpas explained for good oral hygiene. These can be used as a daily regimen to maintain good oral hygiene and in mukharoga as therapeutic procedures. These mukha kriyakalpa- due to their cleaning action and by increasing defence mechanism, promotes oral health and prevents many oral disorders. Various formulations for mukha kriyakalpa are available for a healthy person based on prakriti and for treatment based on vitiated dosha avastha. Keywords: Mukha kriyaklpa, Oral hygiene, kavala, Gandusha, Pratisarana.

Viruses of the oral cavity: Prevalence, pathobiology and association with oral diseases.

The human oral cavity contains a plethora of habitats and tissue environments, such as teeth, tongue, and gingiva, which are home to a rich microbial flora including bacteria, fungi, and viruses. Given the exposed nature of the mouth, oral tissues constantly encounter infectious agents, forming a complex ecological community. In the past, the discussion of microbiological aspects of oral disease has traditionally focused on bacteria and fungi, but viruses are attracting increasing attention as pathogens in oral inflammatory diseases. Therefore, understanding viral prevalence, pathogenicity, and preference regarding oral tissues is critical to understanding the holistic effects of viruses on oral infections. Recent investigations have demonstrated the abundance of certain viruses in oral inflammatory diseases, suggesting an association between viruses and disease. Human herpesviruses are the most extensively studied viruses in different oral inflammatory diseases. However, challenges in viral detection and the lack of reproducible in vitro and in vivo infection models have limited our progress in understanding viruses and their contribution to oral diseases. This review presents a summary of major mammalian viruses and associated diseases in the human oral cavity. The emergence of a recent pathogen SARS-CoV-2 and its tropism for salivary and periodontal tissues further highlights the relevance of the oral cavity in host-pathogen interaction. Understanding how these different viruses present clinically and influence oral health will advance our understanding of multifactorial oral diseases and their association with viruses.

Self-assembled nanoparticles containing photosensitizer and polycationic brush for synergistic photothermal and photodynamic therapy against periodontitis

BackgroundPeriodontitis is a chronic inflammatory disease in oral cavity owing to bacterial infection. Photothermal therapy (PTT) and photodynamic therapy (PDT) have many advantages for antibacterial treatment. As an excellent photosensitizer, indocyanine green (ICG) shows prominent photothermal and photodynamic performances. However, it is difficult to pass through the negatively charged bacterial cell membrane, thus limiting its antibacterial application for periodontitis treatment.ResultsIn this work, self-assembled nanoparticles containing ICG and polycationic brush were prepared for synergistic PTT and PDT against periodontitis. First, a star-shaped polycationic brush poly(2-(dimethylamino)ethyl methacrylate) (sPDMA) was synthesized via atom transfer radical polymerization (ATRP) of DMA monomer from bromo-substituted β-cyclodextrin initiator (CD-Br). Next, ICG was assembled with sPDMA to prepare ICG-loaded sPDMA (sPDMA@ICG) nanoparticles (NPs) and the physicochemical properties of these NPs were characterized systematically. In vitro antibacterial effects of sPDMA@ICG NPs were investigated in porphyromonas gingivalis (Pg), one of the recognized periodontitis pathogens. A ligature-induced periodontitis model was established in Sprague–Dawley rats for in vivo evaluation of anti-periodontitis effects of sPDMA@ICG NPs. Benefiting from the unique brush-shaped architecture of sPDMA polycation, sPDMA@ICG NPs significantly promoted the adsorption and penetration of ICG into the bacterial cells and showed excellent PTT and PDT performances. Both in vitro and in vivo, sPDMA@ICG NPs exerted antibacterial and anti-periodontitis actions via synergistic PTT and PDT.ConclusionsA self-assembled nanosystem containing ICG and polycationic brush has shown promising clinical application for synergistic PTT and PDT against periodontitis.Graphical

Antioxidant-Rich Natural Raw Materials in the Prevention and Treatment of Selected Oral Cavity and Periodontal Diseases.

Antioxidant-rich natural raw materials have been used for thousands of years in traditional medicine. In the past decade, there has been increasing interest in naturotherapy, which is a practice of using products with a natural origin. Natural products can be effective in the treatment and prevention of oral and dental diseases, among others. Such raw materials used in dentistry are characterized by antioxidant, anti-inflammatory, antibacterial, antiviral, antiedematous, astringent, anticoagulant, dehydrating, vitaminizing, and—above all—regenerative properties. Reports have shown that a relationship exists between oral diseases and the qualitative and quantitative composition of the microbiota colonizing the oral cavity. This review aimed to analyze the studies focusing on the microbiome colonizing the oral cavity in the context of using natural raw materials especially herbs, plant extracts, and isolated biologically active compounds as agents in the prevention and treatment of oral and periodontal diseases such as dental caries as well as mucosal changes associated with salivary secretion disorder. The present work discusses selected plant ingredients exhibiting an antioxidant activity with potential for the treatment of selected oral cavity and periodontal diseases.

ЭФФЕКТИВНОСТЬ ПРОФИЛАКТИКИ ЗАБОЛЕВАНИЙ РОТОВОЙ ПОЛОСТИ У ДЕТЕЙ. ЗНАЧЕНИЕ ВОПРОСА ДЛЯ СЛАБОВИДЯЩИХ ДЕТЕЙ

Subject. Dentine pathology is widely prevalent among children in many countries around the globe, which determines the relevance of consideration, organisation and performance of different forms of health education activities for this part of the population. Programmes for dental disease prevention are represented by different methods and means, the purpose of which is creation of correct skills and abilities aimed at preservation and maintenance of oral cavity health. For blind and hyposeeing children, there is absence of special technology for teaching dental culture and rational hygiene of the oral cavity.
 Aim – studying and analysis and literature related to forms and methods of health education activities for children with consideration for their somatic status.
 Methods.The study was carried out based on the search for and analysis of original articles devoted to issues of dental disease prevention among children and adolescents in the following databases: ELIBRARY, PubMed, Medline, Cyberleninka. A total of 45 sources have been analysed (25 by Russian and 20 foreign authors).
 Conclusions. Preventive dental care programmes for conventionally healthy children at the modern stage of development are sufficiently effective, diverse in their contents, point at the necessity of further introduction of individual preventive care activities. Few organisational forms of health education activities have been developed for children with health limitations. There is no special method for organisation of health education activities for blind and hyposeeing children. These circumstances point at the necessity of development and introduction of correction methods for primary prevention of oral cavity diseases for this category of subjects.

RDFNet: A Fast Caries Detection Method Incorporating Transformer Mechanism.

Dental caries is a prevalent disease of the human oral cavity. Given the lack of research on digital images for caries detection, we construct a caries detection dataset based on the caries images annotated by professional dentists and propose RDFNet, a fast caries detection method for the requirement of detecting caries on portable devices. The method incorporates the transformer mechanism in the backbone network for feature extraction, which improves the accuracy of caries detection and uses the FReLU activation function for activating visual-spatial information to improve the speed of caries detection. The experimental results on the image dataset constructed in this study show that the accuracy and speed of the method for caries detection are improved compared with the existing methods, achieving a good balance in accuracy and speed of caries detection, which can be applied to smart portable devices to facilitate human dental health management.

Zinc Oxide and Copper Chitosan Composite Films with Antimicrobial Activity.

The role of the oral microbiome and its effect on dental diseases is gaining interest. Therefore, it has been sought to decrease the bacterial load to fight oral cavity diseases. In this study, composite materials based on chitosan, chitosan crosslinked with glutaraldehyde, chitosan with zinc oxide particles, and chitosan with copper nanoparticles were prepared in the form of thin films, to evaluate a new alternative with a more significant impact on the oral cavity bacteria. The chemical structures and physical properties of the films were characterized using by Fourier transform infrared spectroscopy (FTIR,) Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), elemental analysis (EDX), thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), and contact angle measurements. Subsequently, the antimicrobial activity of each material was evaluated by agar diffusion tests. No differences were found in the hydrophilicity of the films with the incorporation of ZnO or copper particles. Antimicrobial activity was found against S. aureus in the chitosan film crosslinked with glutaraldehyde, but not in the other compositions. In contrast antimicrobial activity against S. typhimurium was found in all films. Based on the data of present investigation, chitosan composite films could be an option for the control of microorganisms with potential applications in various fields, such as medical and food industry.

Розвиток захворюваності на непухлинні хвороби органів травлення у дорослих осіб після евакуації із 30-кілометрової зони ЧАЕС протягом 1992-2016 років епідеміологічного спостереження

Objective: We analyzed the absolute risk of the development of the incidence of non-neoplastic diseases of the digestive system in adults evacuated from the 30-kilometer zone of the Chornobyl NPP over 1992–2016 epidemiological surveillance. Materials and methods: For the epidemiological study of the incidence of non-neoplastic diseases of the digestive system in the evacuated from the 30-kilometer Chornobyl zone after the Chornobyl accident in 1992–2016 we formed a cohort of 7,143 people aged 18 years and older (2,198 men and 4,945 women). To study the features of the incidence of diseases of the digestive system over the years of observation, we calculated the epidemiological indicator - the absolute risk of development (AR). Results: During 1992–2016, 13,532 cases of the diseases of the digestive system: 3,298 (24.37%) – in men; 10,234 (75.63%) - in women) were revealed for the first time. The absolute risk of the development of digestive diseases makes up 467.64 ± 2.93 cases per 103 man-years of observation (further cases/103 man-years). It was found that 91.05% (12,321 cases) with an absolute risk of 425.32 ± 5.89 93 cas./103 man-years ( 423.22 ± 5.89- in men, 426.19 ± 3, 34 - in women) belonged to the class of the diseases of digestive system (C00-C93). Mostly diseases of oral cavity, salivary glands and jaws (C00 – C14) (200.63 ± 4.77 cases/103 man-years), esophageal diseases, stomach and duodenum (C20 – C31) (146.26 ± 4.21 93) were manifested. Significant loss of health was also caused by the diseases of the gallbladder, biliary tract and pancreas (C83–C87) (50.23 ± 2.60 93), liver disease (C70-C77) – (22.44 ± 1.76 93), non-infectious enteritis and colitis (C50–C52) – (3.93 ± 8.75), other intestinal diseases (C55–C63) – (1.83 ± 0.51) respectively. Irrespective of gender, the development of the incidence of non-neoplastic diseases of the digestive system is characterized by the identity of the diseases and the ratio of their values to the total cohort. However, women suffered more from the diseases of the gallbladder, biliary tract and pancreas, diseases of the oral cavity, men – from the diseases of esophagus, stomach and duodenum. Conclusions: 1. The revealed features of the development of digestive diseases in the evacuated from the 30-kilometer zone of the Chornobyl NPP (high absolute risks of diseases of oral cavity, salivary glands and jaws (C00–C14), diseases of esophagus, stomach and duodenum (C20–C31), biliary diseases bladder, biliary tract and pancreas (C80–C87)) need the improvement of medico-social measures to provide qualitative treatment-and-preventive, rehabilitative care from the primary level of medical care. 2. It is necessary to conduct medico-educational work on radiation hygiene, regimen, food intake and dietary nutrition for the minimization of the development of established prior nosological forms in the evacuees from the 30-kilometer zone of the ChNPP.

Relationship between the oral cavity and respiratory diseases: Aspiration of oral bacteria possibly contributes to the progression of lower airway inflammation.

The global population is aging, and elderly people have a higher incidence of lower airway diseases owing to decline in swallowing function, airway ciliary motility, and overall immunity associated with aging. Furthermore, lower airway diseases in the elderly tend to have a high mortality rate. Their prevention is important for extending healthy life expectancy and improving the quality of life of each individual.In recent years, the relationship between “chronic periodontitis and oral bacteria, especially the periodontopathic ones” and “respiratory diseases” (e.g., pneumonia, chronic obstructive pulmonary disease, and influenza) has become clear. In addition, the association of several periodontal pathogens with the onset and aggravation of coronavirus disease 2019 (COVID-19) is also being reported.In support of these findings, oral health management has shown to reduce deaths from pneumonia and prevent influenza in nursing homes and inpatient wards. This has led to clinical and multidisciplinary cooperation between physicians and dentists, among others. However, to date, the mechanisms by which “chronic periodontitis and oral bacteria” contribute to lower airway diseases have not been well understood. Clarifying these mechanisms will lead to a theoretical basis for answering the question, “Why is oral health management effective in preventing lower airway diseases?”

Salivary biomarkers and proteomics: future diagnostic and clinical utilities

The search for new, fast and non-invasive methods of diagnosing diseases of both the oral cavity and general diseases of various etiologies and their introduction into practical health care is still a priority in the field of medicine. Among the known methods of analysis of biological fluids, a special place is occupied by the study of saliva. Oral fluid analysis has a high potential in screening for various diseases, since it contains a wide range of organic and inorganic compounds. A significant number of works have been devoted to the study of the quantitative and qualitative composition of the oral fluid, as well as to the study of saliva biomarkers, however, the study of the saliva proteome is at the stage of data accumulation. The lack of standardization in the collection of samples and methods of analysis, as well as poorly studied physiological and biochemical parameters of the oral fluid, hinders the introduction of advances in the study of the saliva proteome into diagnostic practice. The solution of these problems will allow the oral fluid to be used as a biological environment for both detecting diseases and predicting their course.

English

BACK GR O U ND Gastroesophageal reflux disease (GERD) is highly prevalent across populations with varied manifestations and substantial morbidity. Our review focuses mainly on the role of dental practitioner in GERD, its oral manifestations and management. GERD shows oesophageal and extra oesophageal syndromes. Oesophageal syndromes are reflux chest pain syndrome, typical reflux syndrome, reflux stricture, reflux esophagitis, oesophageal adenocarcinoma and Barrett’s oesophagus. Extra oesophageal syndromes are reflux cough syndrome, reflux asthma syndrome, reflux dental erosion syndrome, reflux laryngitis syndrome, pharyngitis, and sinusitis. Classic reflux symptoms may be absent in more than half the patients presenting with extra oesophageal symptoms. For this reason, the first provisional diagnosis of GERD may be made by a dental practitioner as a result of clinical observation of enamel erosion. A direct association exists between gastroesophageal reflux disease and oral cavity diseases. Dental practitioner can recognise the secondary manifestations of GERD for early diagnosis and can assist in management of these patients. Traditional management of GERD includes medical therapy, non-medical therapy and surgical therapy, in future dental examination and dental treatment can also be included. There is a lack of awareness among the general physicians regarding the association between GERD and dental erosions. According to the study, 40 % of them are aware of dental erosions in GERD, indicating that there is a need to circulate this information through medical education. There should be an interdisciplinary coordination between family physician, dentist, orthodontist, prosthodontist, and gastroenterologist for treatment of oral manifestations resulting from GERD. This review highlights the role of dental practitioner in management of GERD. KEY WORDS Gastro Oesophageal Reflux Disease (GERD), Dental Erosion, Oesophagus, Gastric acid, Saliva

SIGNS OF DISEASES OF THE GASTROINTESTINAL TRACT IN THE ORAL CAVITY OF CHILDREN

The question of combined lesions of the oral cavity and internal organs occupy a prominent place among the problems of dentistry nowadays. They allow to reflect the genesis of many diseases that manifest themselves in the oral cavity.
 Aim of the study was to analyze information on the relationship of diseases of oral cavity and various diseases of gastrointestinal tract.
 Anatomical and physiological proximity, common innervation and humoral regulation leads to the involvement of organs of oral cavity in the pathological process. Catarrhal gingivitis, stomatitis are often caused by deficiency of vitamins of group B. Above-mentioned deficiency is caused, according to many scientists, by the diseases of gastrointestinal tract. And such diseases of the oral cavity as chronic recurrent stomatitis, lichen planus, chronic recurrent herpetic stomatitis, chronic periodontitis depends on the pathology of the digestive tract.
 Conclusions. Thus, anatomical and physiological characteristics of children, who suffers from chronic gastrointestinal diseases, make us study the clinical manifestations of dental diseases in these patients.
 Prospects for further research. Further study of the dental status of children with diseases of the gastrointestinal tract is very valuable.

In vitro antimicrobial activity of Caesalpinia coriaria (Jacq.) Willd extracts on Streptococcus pyogenes and Candida albicans

Background: “Dividivi” Caesalpinia coriaria (Jacq.) Willd fruits are traditionally used by the Wayuú community in La Guajira (Colombia) to treat oral and skin cavity diseases caused by bacteria and fungi. Streptococcus pyogenes is a gram-positive cocci of group A (beta-hemolytic) that is the cause of pharyngeal disease, scarlet fever, cellulitis, erysipelas, or toxic shock-like syndrome. Alternatively, Candida albicans is a yeast-like fungus that is a normal flora of the digestive tract, vagina, or skin folds; it has been known to be the root cause of opportunistic diseases such as diaper rash, oral and esophagus thrush, or vulvovaginitis. Objective: This study evaluated the antimicrobial activity of methanolic and ethanolic extracts of C. coriaria (Jacq.) Willd dry fruits on S. pyogenes ATCC 12384 and C. albicans ATTC 14053. Method: C. coriaria extracts were obtained from the Soxhlet method using two solvents (methanol and ethanol 98%) prepared from pulverized fruits. A phytochemical test and an antimicrobial activity assay were performed using the obtained extracts and tested using S. pyogenes ATCC 12384 and C. albicans ATTC 14053 strains. Results: A phytochemical profile was performed, examining the presence of bioactive metabolites (tannins, alkaloids, glycosides, saponins, and anthraquinones) from each extract. Antimicrobial susceptibility tests showed that the ethanolic extract inhibited S. pyogenes ATCC 12384, causing inhibition halos of 14.1 ± 0.1 mm and a Minimum Inhibitory Concentration (MIC) of 172 mg/ml, and C. albicans test shows inhibition halos of 16.1 ± 0.2 mm and MIC of 212 mg/ml. Additionally, the methanolic extract inhibited S. pyogenes with inhibition halos of 15.2 ± 0.2 mm and MIC of 152 mg/ml; no inhibitory effect was observed on C. albicans. Conclusion: This study revealed that C. coriaria has an antimicrobial effect on the tested species opening the field of its possible use as a therapeutic agent.

Oral aspects related to SARS-CoV-2

The pandemic of coronavirus disease (COVID-19) is considered as the biggest global health crisis for the world since the Spanish flu, also known as the 1918 flu pandemic. Driven by the SARS-CoV-2 novel coronavirus infection, the rapid spread of this disease and the related pneumonia COVID-19 are a challenge for healthcare systems in over the world, and it is a constantly evolving situation with new symptoms and prognostic factors. SARS-CoV-2 has lately been detected in infected patient’s oral cavity; the COVID-19 outbreak is an alert that all dental and other health professionals must be vigilant in defending against the infectious disease spread. This review summarizes an update from current medical literature about the relationship between oral cavity and coronavirus disease by presenting some oral aspects which was detected in infected patients such as the oral lesions related to this virus and its therapeutic protocol, taste disorders and also the diagnostic value of saliva for SARS-CoV-2.

The Impact of Sport Training on Oral Health in Athletes.

Athletes’ oral health appears to be poor in numerous sport activities and different diseases can limit athletic skills, both during training and during competitions. Sport activities can be considered a risk factor, among athletes from different sports, for the onset of oral diseases, such as caries with an incidence between 15% and 70%, dental trauma 14–70%, dental erosion 36%, pericoronitis 5–39% and periodontal disease up to 15%. The numerous diseases are related to the variations that involve the ecological factors of the oral cavity such as salivary pH, flow rate, buffering capability, total bacterial count, cariogenic bacterial load and values of secretory Immunoglobulin A. The decrease in the production of S-IgA and the association with an important intraoral growth of pathogenic bacteria leads us to consider the training an “open window” for exposure to oral cavity diseases. Sports dentistry focuses attention on the prevention and treatment of oral pathologies and injuries. Oral health promotion strategies are needed in the sports environment. To prevent the onset of oral diseases, the sports dentist can recommend the use of a custom-made mouthguard, an oral device with a triple function that improves the health and performance of athletes. During training, the sports dentist must monitor the athletes and the sports examination protocol must be implemented with the inclusion of the clinical examination, quantitative and qualitative analysis of saliva and instructions on the use, cleansing and storage of the mouthguard.

Periodontal Disease in Patients Visiting a Tertiary Care Dental Hospital: A Descriptive Cross-sectional Study.

Periodontitis is chronic disease leading to tooth loss. Oral hygiene practices combined with regular dental examinations keep oral cavity disease free and maintain periodontal health. The primary objective was to find out the prevalence of periodontal disease of patients measured by the Simplified Oral Hygiene Index and Community Periodontal Index. This descriptive cross-sectional study was conducted in department of Periodontics of a tertiary care dental hospital from April to June 2019 after obtaining ethical clearance and informed consent. Participants were recruited by convenience sampling and 183 sample size was calculated. Proforma included demographics, Simplified Oral Hygiene Index, Community Periodontal Index, body mass index, and smoking status. Data were entered in Statistical Package for Social Sciences version 23 and descriptive statistics were presented as frequency, percentage, mean, and standard deviation. Prevalence of periodontal disease corresponding to loss of attachment 1, 2, 3, and 4 was found to in 104 (56.83%) participants. Simplified Oral Hygiene Index score was 1.67±0.89 with "fair" status in majority 114 (62.30%). Gingivitis (Community Periodontal Index 1, 2) was seen in 136 (74.32%). The mean age was 36.37±14.43 years of which 92 (50.27%) were female but smoking was more in males. This study suggests deteriorating periodontal health related to age, sex, oral hygiene, smoking, and BMI. As updated information on oral and periodontal health in Nepal is limited, this assessment would help the national policy makers on oral health intervention measures to prevent periodontitis and develop future programs to improve oral health.

Clinical diagnosis of oral erosive and ulcerative diseases in children.

Mucosal disease is one of the most common oral cavity diseases in children, among which mucosal erosion and ulceration account for about 50%. Oral mucosal erosion and ulcer diseases in children are mostly acute with obvious pain, affecting speech, eating and swallowing. Some oral mucosal diseases are caused by infection and would result in epidemic among children. The onset age, sites, lesions size and quantity could vary, and some would have recurrence. The detailed medical history and comprehensive physical examination are necessary, some diseases can be diagnosed according to the medical history and clinical manifestations. If diagnosis can not be made, biopsy, blood test and immunofluorescence staining, immunohistochemistry, molecular biology detection, gene diagnosis, tuberculin test and other tests should be considered, and further investigation of systemic diseases should also be carried out if necessary. In some cases, multidisciplinary consultation should be sought. For those who still have no abnormal findings, therapeutic diagnosis can be tried out or secondary biopsy should be performed. In this article, the research progress of oral mucosal diseases in children is reviewed and our own clinical experiences of oral erosive and ulcerative diseases in children are summarized.

SPORTS DENTISTRY: A REVIEW

Sports dentistry is one of the most important and upcoming fields in dentistry. Sports dentistry includes the prevention and management of athletics-related orofacial injuries and associated oral cavity diseases. The most noteworthy angle in forestalling sports-related orofacial injuries is guarding up with defensive devices, for example, appropriately fitting helmets, face masks and additionally mouth guards. Athletes are not well versed of the health implications of a traumatic injury to the mouth or of the potential for incurring severe head and orofacial injuries while playing.The dentist can play an essential role in notifying athletes, coaches and patients about the importance of preventing orofacial injuries in sports. The present article aims to elevate professional awareness and interest towards sports dentistry and the injuries. Keywords: Dental injury, Sports dentistry, Mouth guard, Orofacial injuries.

Oral Microbial Diversity Formed and Maintained through Decomposition Product Feedback Regulation and Delayed Responses.

Oral microbial diversity plays an important role on oral health maintenance. However, there are only few kinds of substrates available for the microbial flora in oral cavity, and it still remains unclear why oral microbial diversity can be formed and sustained without obvious competitive exclusion. Based on experimental phenomena and data, a new hypothesis was proposed, namely, the decomposition product negative feedback regulation on microbial population size and microbial delay responses including reproductive, reaction, interspecific competition, and substrate decomposition delay responses induced by oral immunity. According to hypothesis and its cellular automata (CA) model, the CA simulation results sufficiently proved that the decomposition product negative feedback regulation and four microbial delay responses could significantly alleviate the interspecific competitions and inhibit the emergence of dominant species, causing the formation and sustenance of oral microbial diversity. This study could also offer effective guidance of prevention and treatment of oral cavity diseases.