Awareness and prevalence of stress induced oral ulcers among clinical medical and dental students in university of Benin:a cross-sectional study

Background:Awareness of clinical medical and dental students towards stress induced oral ulcer,to determine the most prevalent stress induced oral ulcers among the study population,and the relationship between perceived stress level and prevalence of stress induced oral ulcer.Methods:A descriptive cross-sectional study,involving clinical Medical and Dental students in College of Medical Sciences,University of Benin.Participants were in their 400,500,and 600 levels respectively with a sample size of 226 calculated using the Cochran formula for sample size determination.Data were collected using self-administered questionnaire.Results:Two hundred and twenty-six respondents were interviewed in this survey.The age of the participants varied from 21-30 years,with mean age of 25.5%.Majority of the respondents(66.4%)were aware of stress induced oral ulcer.The prevalence of stress induced oral ulcer in this study was 12.8% with recurrent aphthous ulcers accounting for a prevalence of 35.5% of all stress induced oral ulcers.Conclusion:Findings from this study shows about 66.4%of clinical Medical and Dental students were aware of stress induced oral ulcer.The prevalence of stress induced oral ulcer in this study was 12.8%and was seen more in males than females,with recurrent aphthous ulcer been the most prevalent stress induced oral ulcer among the study population with a prevalence of about 35.5%.

Oral microbiota and host innate immune response in bisphosphonate-related osteonecrosis of the jaw

Bacterial biofilms have emerged as potential critical triggers in the pathogenesis of bisphosphonate（BP）-related osteonecrosis of the jaw（ONJ） or BRONJ. BRONJ lesions have shown to be heavily colonized by oral bacteria, most of these difficult to cultivate and presents many clinical challenges. The purpose of this study was to characterize the bacterial diversity in BRONJ lesions and to determine host immune response. We examined tissue specimens from three cohorts（n530）; patients with periodontal disease without a history of BP therapy（Control, n510）, patients with periodontal disease having history of BP therapy but without ONJ（BP, n55） and patients with BRONJ（BRONJ, n515）. Denaturing gradient gel electrophoresis of polymerase chain reaction（PCR）-amplified 16 S r RNA gene fragments revealed less bacterial diversity in BRONJ than BP and Control cohorts. Sequence analysis detected six phyla with predominant affiliation to Firmicutes in BRONJ（71.6%）, BP（70.3%） and Control（59.1%）. Significant differences（P,0.05） in genera were observed, between Control/BP, Control/BRONJ and BP/BRONJ cohorts. Enzyme-linked immunosorbent assay（ELISA）results indicated that the levels of myeloperoxidase were significantly lower, whereas interleukin-6 and tumor necrosis factor-alpha levels were moderately elevated in BRONJ patients as compared to Controls. PCR array showed significant changes in BRONJ patients with downregulation of host genes, such as nucleotide-binding oligomerization domain containing protein 2, and cathepsin G, the key modulators for antibacterial response and upregulation of secretory leukocyte protease inhibitor, proteinase 3 and conserved helix–loop–helix ubiquitous kinase. The results suggest that colonization of unique bacterial communities coupled with deficient innate immune response is likely to impact the pathogenesis of ONJ.

Radiation-induced oral mucositis hamster model using a linear accelerator enhances clinical relevance of preclinical studies for treatment strategy investigation

Translational animal models for oral mucositis(OM)are necessary to simulate and assess the bioclinical effects and response in humans.These models should simulate high levels of radiation exposure that leads to oxidative stress and inflammatoryinitiated tissue changes.Hamster models have been extensively studied to observe pathological effects of radiation exposure and help in the development of effective treatments.To successfully evaluate the potential for treatment regimens with consistency and relevance,a radiation-induced OM hamster model was developed using a clinical linear accelerator utilized by cancer patients daily.The dose exposure to the isolated,everted cheek pouch of a hamster,as well as the progression of injury,proinflammatory marker,histological,and elasticity analyses of the buccal pouch were conducted to verify replicability and reproducibility of the injury model.The findings from this model demonstrated its ability to consistently induce injury and resolution over 28 days using an acute dose of 60 Gy.This model was developed to enhance clinical relevance when evaluating potential efficacious treatments and can now be utilized in efficacy studies to better evaluate developed therapeutics in a preclinical model that is easy to translate to clinical studies..

The role of Langerhans cells in oral squamous cell carcinoma

During the initiation, promotion, and progression of multi-step carcinogenesis, changes in specific host immuno- logical factors have been observed. Although immunology of oral cancer has long been focused on antigens and lymphocytes, the fact remains that the antigen presenting cells, like the Langerhans cells （LCs） of the epithelium are initiators and modulators of the immune response. LCs as sentinels of immune response, have been investigated in several orai mucosal diseases, including cancer. Inadequate presentation of tumor antigens by host dendritic cells is one potential mechanism that allows tumor progression, tn this review, the role of LCs in OSCC is discussed. Elucidation of the role of APCs, in particular LCs, may help to better understand the mechanisms underlying anti-tumour immune responses and, improve the effectiveness of anti-cancer immunity in tumour-bearing hosts. This section focuses on the roles LCs in the immunity of cancer and how cancer bypasses the dendritic cell-mediated immune responses, are discussed. Subsequently, the effects of tumor microenviornment on LC＇s and their therapeutic implications are elaborated.

Delayed Management of Parotid Sialocele:Role for Two-week Intraoral Drainage

Iatrogenic injury or trauma to the salivary gland duct is one of the most common causes of parotid sialoceles,which are usually superficial,soft,and filled with saliva.The enrolled 7 patients with parotid sialocele were divided into two groups:trauma group(4 cases)and iatrogenic group(3 cases).No evidence of recurrence or cranial nerve injuries were observed.With persisted parotid sialocele,intraoral drainage for two weeks as a safe and inexpensive method is recommended.

Central Granular Cell Odontogenic Tumor: A Literature Review of Cases Reported in the Last 71 Years with a New Case Report

Central granular cell odontogenic tumors(CGCOTs)are rare,benign,slowly growing odontogenic neoplasms.Due to their uncertain histogenesis,CGCOTs are still not included as a distinct entity in the WHO classification(2017)of odontogenic tumors.We report a case of CGCOT involving the right side of maxillary anterior region of a 39-year-old white female.Immunohistochemical staining showed that granular cells positively expressed CD68 and vimentin,and negatively expressed S-100 protein.Meanwhile,we searched Pub Med,Google Scholar,and Scopus databases to summary the clinico-pathological features of 51 reported cases of CGCOT.The results showed that the granular cells of 28.6%cases were immunopositive for vimentin and CD68,and odontogenic epithelial cells were positive immunoreactivity for cytokeratin.These findings reinforced the mesenchymal origin of granular cells and the odontogenic nature of epithelium islands.

Therapeutic potential of periodontal ligament stem cells

Inflammatory periodontal disease known as periodontitis is one of the most common conditions that affect human teeth and often leads to tooth loss.Due to the complexity of the periodontium,which is composed of several tissues,its regeneration and subsequent return to a homeostatic state is challenging with the therapies currently available.Cellular therapy is increasingly becoming an alternative in regenerative medicine/dentistry,especially therapies using mesenchymal stem cells,as they can be isolated from a myriad of tissues.Periodontal ligament stem cells(PDLSCs)are probably the most adequate to be used as a cell source with the aim of regenerating the periodontium.Biological insights have also highlighted PDLSCs as promising immunomodulator agents.In this review,we explore the state of knowledge regarding the properties of PDLSCs,as well as their therapeutic potential,describing current and future clinical applications based on tissue engineering techniques.

Squamous Papilloma:Case Report and Review of Literature

Squamous papillomas are common lesions of the oral mucosa with a predilection for the mucosa of the hard and soft palate. As an oral lesion,it raises concern because of its clinical appearance,which may mimic exophytic carcinoma,verrucous carcinoma or condyloma acuminatum. Its pathogenesis is related to human papilloma virus but there is controversy regarding its viral origin. We present a case of squamous papilloma presenting as oral lesion along with a review of the literature.

Circulation of Brucellaceae,Anaplasma and Ehrlichia spp.in borderline of Iran,Azerbaijan,and Armenia

Objective:To estimate the infection of ticks to Anaplasma,Ehrlichia,Babesia,Theileria,and Brucellaceae using molecular methods in borderline of Iran,Azerbaijan,and Armenia.Methods:Totally,2022 ticks were collected from different livestock.Then,species were diagnosed under stereomicroscope according to valid morphological keys.Tick DNA was extracted followed by PCR to detect Anaplasma,Ehrlichia,Theileria,Babesia and Brucellaceae infection in ticks.Results:A total of 498 males[24.62%(95%CI 22.76%-26.57%)],741 females[36.64%(95%CI 34.54%-38.79%)],782 nymphs[38.67%(95%CI 36.55%-40.84%)]and 1 larva[0.04%(95%CI 0.00%-0.28%)]were identified.Among identified samples,we found four genera including Hyalomma,Rhipicephalus,Haemaphysalis,and Dermacentor.Molecular assay revealed that the prevalence of ticks to Anaplasma or Ehrlichia,and Brucellaceae was 22.02%(95%CI 16.01%-29.06%)and 15.03%(95%CI 9.43%-22.26%),respectively.Phylogenetic analysis showed that the identified Anaplasma sp.had the most similarity with Anaplasma centrale,Anaplasma platys,Anaplasma camelii,and Anaplasma phagocytophilum,submitted in GenBank.Furthermore,the detected Ehrlichia sp.and Brucellaceae bacterium had the most similarity with Ehrlichia ruminantium and Mycoplana peli,respectively.However,no sign of the presence of Theileria and Babesia spp.was seen in the studied samples.Conclusions:Anaplasmosis,ehrlichiosis and brucellosis should be considered as important health threats in northwestern Iran and consistent monitoring on infection of ticks and livestock should be performed regularly.

Topology Optimization and Fatigue Analysis of Temporomandibular Joint Prosthesis

Treatment of bone tumors in the mandible often involves extensive excavation of affected bone, followed by mandibular reconstruction. Prosthetic implants may be needed to restore jaw functionality. The challenges of making prosthetic bone implants include stress shielding and extending the mechanical life of the implant. We have developed a design algorithm to improve the efficiency of prosthesis design. A finite element model of the patient case is constructed from a computer tomography scan, and the computer implements topology optimization techniques to design the prosthesis with limited stress shielding affected by highly biomechanical compatibility. Topology optimization facilitates the design of low weight structures by automatically introducing holes into the structure. This is governed by engineering predetermined constraints to meet certain job specifications. Such a design will be tested for fatigue life before it is ready to be manufactured and used. Topology optimization can be performed as a design process to achieve a final design that takes stress shielding into consideration. The problem of stress shielding is solved by matching the stiffness of the orthopedic implant to the original bone that is being replaced. The material we used was titanium alloy (Ti-6Al-7Nb). Volume fraction of the orthodox implant was used (0.2872 for the studied case) as volume constraints. Compliance of the bulk bone was set as a further constraint to match the stiffness of the bone with the designed structure. Our results show a good life expectancy for the designed parts, with 12% higher life expectancy for stress-based topology optimization than for compliance-based topology optimization.

Enhancement of Gingival Wound Healing by Local Application of Silver Nanoparticles Periodontal Dressing Following Surgery: A Histological Assessment in Animal Model

Background: The value of periodontal dressing and its effects on periodontal wound healing have been questioned. Besides, the early healing of the gingival and periodontal wounds in oral cavity should be emphasized to promote the treatment outcome. Several studies pointed out a potential positive effect of silver nanoparticles (NPs) on the healing process of skin wounds. The present work aimed to design silver NPs periodontal dressing and then, evaluated its effects on gingival wound healing following operation. Methods: Thirty healthy adolescent female rabbits were used in this study. They had intact teeth and the clinical and radiographic examination revealed no periodontal disease. Silver NPs were added to carbonate methyl cellulose as base with two different concentrations of 25% v/v (Group A) and 50% v/v (Group B). On the basis of simple randomized allocation, gingivectomy was performed at the buccal gingiva of the left and right mandibular incisors and subsequently, untreated wounds in the control area were covered with periodontal pack and periodontal dressings A and B were applied in the test regions. Histological changes were monitored in day 4 and 7 post operation to evaluate the inflammatory and repair stage of healing process. Results: We observed significant difference in the inflammatory and repair parameters of the healing process between surgical sites treated with this periodontal dressing and control group. Besides, wounds treated with silver NPs dressing in general terms had all the hallmarks of relatively complete healing one week post operatively. Conclusion: The results indicated positive potential therapeutic effects for this new formulation of periodontal dressing on acceleration of surgical wound healing that led to improvement of periodontal treatment consequences following operation.

Mixed odontogenic tumors:A review of the clinicopathological and molecular features and changes in the WHO classification

BACKGROUND Ameloblastic fibromas and ameloblastic fibrosarcomas are rare odontogenic tumors,and controversy exists in the classification of cases presenting hard-tissue production:Ameloblastic fibrodentinoma(AFD)and ameloblastic fibro-odontoma(AFO).These cases are currently considered“developing odontomas”(hamartomatous lesions).AIM To analyze the clinicopathologic features of these lesions and discuss the changes in the 2017 World Health Organization classification.METHODS An electronic literature search was performed in the PubMed/MEDLINE database.An electronic search of the English language literature was performed and last updated in September 2020 in the PubMed/MEDLINE database using the following terms:“ameloblastic fibroma”,“ameloblastic fibrodentinoma”,“ameloblastic fibro-odontoma”,“ameloblastic sarcoma”,“ameloblastic fibrosarcoma”,“ameloblastic fibrodentinosarcoma”,“ameloblastic fibroodontosarcoma”and“odontogenic carcinosarcoma”.The inclusion criteria were odontogenic tumor series,case reports and systematic reviews that provided sufficient clinical,radiological and microscopic documentation to confirm the diagnosis.RESULTS The database search strategy resulted in 947 papers.Articles focusing on other topics,articles that were not in English,duplicate articles,and articles without fulfilling the inclusion criteria were excluded.Finally,96 publications were included in this review to describe and discuss the main features of the searched entities.Several aspects of AFO and AFD,such as biological behavior,age of occurrence,amount of hard tissue,and potential for malignant transformation into odontogenic sarcomas,support the neoplastic nature in most of the reported cases.Considering the clinical,radiographic,histopathological and molecular characteristics of odontogenic lesions with hard tissue production,we suggest that these types of lesions should continue to be recognized as odontogenic tumors by maintaining the classically used terms.CONCLUSION This recommendation will be relevant for future clinical,microscopic,and molecular studies to better understand the biology of these interesting odontogenic tumors.

Self-Medication for Oral Health Problems among Dental Outpatients at a Nigerian Tertiary Hospital

Background: Self-medication is the inappropriate use of drugs to treat self-diagnosed disorders or symptoms. Even though Self-medication has benefits as it enhances better use of clinical skills and increases access to medication;it is also associated with risks such as adverse drug reactions and antibiotics resistance. Objectives: To determine prevalence of self-medication practices among dental out-patients, triggering factors that influence self-medication practice and common source of drugs. Materials and methods: This descriptive cross-sectional study was conducted at the Clinic of the Department of Preventive Dentistry, Lagos University Teaching Hospital over a period of 6 months using self-administered questionnaires adapted from previous studies. Data obtained was analysed and expressed as frequencies and percentages. Test of associations was done using chi-square (p Results: Age of respondents ranged from 16 to 78 years (32.24 ± 13.47). M:F was 1:1. Prevalence of self-medication was 45.5%;toothache was the most prevalent reason for self-medication (71%). The frequently used drugs for self-medication were analgesics (65%) while the most common source for the drugs was the pharmacy (60%). Educational status (X2 = 12.85, P 2 = 6.42, P 2 = 10.38, P Conclusion: This study revealed high prevalence of self-medication with toothache as the predominant trigger and pharmacy, the most common source.

Enhancement of Periodontal Healing by Application of a Novel Ointment Compared with Hyaluronic Acid, Histological Observation in Animal Model

Objectives:?The early healing of the periodontal wound in oral cavity may be critical to the treatment outcome. Thus, we made a novel ointment based on natural constituents that our recent investigation suggested a positive therapeutic effects on gingival wounds. The present study was conducted to evaluate the role of this novel biomaterial on periodontal wound healing including soft as well as hard tissue. Materials and Methods: Experimental periodontitis was induced by wire tied around the cement-enamel junction of I2, P1, P3?and M1?in six adult, healthy beagle dogs. After 3 months, mucoperiostal flap elevated and root surfaced was thoroughly scaled and planed. Randomly, three materials including our ointment with two different ratios including materials A and B and hyluronic acid were applied topically and then the flaps were repositioned and sutured. Three dogs at day 7 and the three remaining ones two weeks post-surgery were sacrificed and histological changes were monitored. Results: The result of this study showed that the local applications of this novel ointment promoted the healing process particularly fibroblast proliferation and collagen density remarkably in comparison with hyaluronic acid and control group. Besides, histological finding of our material revealed that in general terms had all the hallmarks of complete healing two weeks post operatively. Conclusion: Our novel material appeared to have outstanding effect on periodontal wound healing which can improve the periodontal healing consequences and provide better strength of periodontal wound flap. From a clinical standpoint, it could play an important role for better repair in diabetic patients who frequently present difficulties in mucosal and cutanous wound healing.

Investigation of basement membrane proteins in a case of granular cell ameloblastoma

Granular cell ameloblastoma is a rare,benign neoplasm of the odontogenic epithelium.A case of massive granular cell ameloblastoma in a 44-year-old Thai female is reported.Histopathological features displayed a follicular type of ameloblastoma with an accumulation of granular cells residing within the tumor follicles.After treatment by partial mandibulectomy,the patient showed a good prognosis without recurrence in a 2-year follow-up.To characterize the granular cells in ameloblastoma,we examined the expression of basement membrane（BM） proteins,including collagen type IV,laminins 1 and 5 and fibronectin using immunohistochemistry.Except for the granular cells,the tumor cells demonstrated a similar expression of BM proteins compared to follicular and plexiform ameloblastomas in our previous study,whereas the granular cells showed strong positivity to laminins 1 and 5 and fibronectin.The increased fibronectin expression in granular cells suggests a possibility of age-related transformation of granular cells in ameloblastoma.

Odontoma: Case series &report of cases complicated by infection and multiple denticles

Odontoma is a hamartomatous lesion of odontogenic origin involving both epithelial and mesenchymal tissues. Although it is not an uncommon lesion yet in certain conditions it can lead to complications if left untreated. This is a retrospective review of 30 diagnosed odontoma cases from the archives of Department of Oral & Maxillofacial Surgery, Government Dental College & Hospital, Nagpur, India. Out of these 30 cases, 17 were diagnosed as complex odon toma and 13 cases as compound odontoma. Two of these unusual cases have been described which emphasize the importance of early & appropriate treatment to prevent further morbidity.

Clinical and radiographic features of Hutchinson-Gilford progeria syndrome: A case report

Hutchinson-Gilford progeria syndrome(HGPS) is a rare dysmorphic syndrome characterized by several features of premature aging with clinical involvement of the skin, bones, and cardiovascular system. HGPS has an estimated incidence of one in four million to one in eight million births. The main clinical features of HGPS include short stature, craniofacial dimorphism, alopecia, bone fragility, and cardiovascular disorders. The most frequent cause of death is myocardial infarction at a mean age of 13 years old. Dental manifestations include delayed development and eruption of teeth, discoloration, crowding and rotation of teeth, and displaced teeth. Cone beam computed tomography images revealed the absence of the sphenoid, frontal, and maxillary sinus, flattening of the condyles and glenoid fossa, and bilateral hypoplasia of the mandibular condyles. The disease is caused by mutations in lamin A/C(LMNA). Here, we present a case report of an 11-year-old boy with classical features of HGPS, which was caused by a de novo germ-line mutation(C1824T, G608G) in exon 11 of the LMNA gene. Some uncommon HGPS-associated features in our patient, such as alterations in the facial sinuses and hypoplasia of the condyles, contributed to the expansion of the phenotypic spectrum of this syndrome from a dentomaxillofacial perspective.

Synoptic review on existing and potential sources for bias in dental research methodology with methods on their prevention and remedies

The results of years of dental study serve as the foundation for the practise of medicine and,for that matter,dentistry.Doctors may have their own preferences for techniques and materials,but whether directly or indirectly,their decisions are influenced by systematic reviews and meta-analyses.However,due to poorly conducted or presented research,this very basic foundation may not be reliable.Bias in research is one of several factors that might make study results or research itself unreliable.Bias can be introduced into research at many stages,deliberately or unknowingly.Bias can appear at any point during the research process,even before the study itself begins.There are many biases in research,but some of them are more relevant to dentistry research than others.Because it is said that“eyes see what the mind knows”,it is essential to have a complete understanding of the different types of bias,how and when they get entrenched,and what steps may be taken to prevent or lessen them if they do occur.This comprehensive summary of bias in dentistry research is provided by this synoptic review.The goal is to identify gaps and measures that have been taken-or that should have been taken-by providing both descriptive and evaluative summaries,as well as examples from the literature,when needed.

Comparison of the Anatomy and Adaptability of Reconstructed Teeth with Natural Teeth:An Innovative Approach in Forensic Dentistry

Background:Forensic tooth reconstruction is the technique of reconstructing the morphology of a missing tooth from the intra-alveolar morphology of dental sockets from skeletal remains.Aims and Objectives:The aim and objective of the study are to compare and investigate whether the anatomy and adaptability of reconstructed teeth simulate with the natural tooth and to investigate whether the dental materials have potential in reconstruction of teeth.Materials and Methods:An in vitro experimental study was undertaken on a human mandible.According to the Fédération Dentaire Internationale,charting will be done based on the number of teeth present.The entire study will be conducted in three phases using dental materials.Phase 1 comprised preparation for negative replica,where an impression will be taken,Phase 2 comprised preparation of a positive replica or cast,and Phase 3 comprised tooth reconstruction using the flowable composite.Results:The specimen tooth(which had been taken from its socket)and the newly constructed tooth were compared,and when the length of the newly constructed root was measured using digital vernier calipers,there was a disparity of 0.5-1 mm.The cone-beam computed tomography radiographs demonstrated the necessary flexibility.Conclusion:The present study demonstrated that dental information can be obtained even when teeth are absent postmortem by making an attempt to recreate the teeth using dental materials while documenting the intra-alveolar anatomy of the dental root socket.