Age and the architecture of oral mucosa

Assessing current clinical eruption stage of mandibular third molars by dental panoramic radiography

OBJECTIVE

We examined whether dental panoramic radiography (PAN) can be used to identify the clinical stage of eruption of mandibular third molars at the time of radiological examination.

MATERIALS AND METHODS

Cross-sectional data included records from clinical oral examination and PANs of university students. In the retrospective analysis of 345 mandibular third molars in 189 participants (20% men, 80% women; mean age 20.7 years; standard deviation [SD] ± 0.6), clinical stages of eruption were compared with their radiographic depth in bone, inclination, and root development. Statistics included χ2, Mann-Whitney U tests, and logistic regression.

RESULTS

Significant (p < 0.001) predictor variables for assessing the clinical stage of eruption were radiographic depth in bone and inclination. All teeth radiologically at a depth of the cementoenamel (CE) junction of the neighbouring second molar or deeper were clinically unerupted. Above the CE junction, 80% of vertical and 97% of distoangular teeth were connected to the oral cavity, and 82% of mesioangular and 69% of horizontal teeth were clinically unerupted.

CONCLUSION

All teeth below or at the CE junction are clinically unerupted. Above the CE junction, stage of eruption should be assessed together with the inclination, but horizontally inclined teeth are recommended to be verified clinically.

Human Oral Mucosa as a Potentially Effective Source of Neural Crest Stem Cells for Clinical Practice

We report in this study on the isolation and expansion of neural crest stem cells (NCSCs) from the epithelium of oral mucosa (OM) using reagents that are GMP-certified and FDA-approved for clinical use. Characterization analysis showed that the levels of keratins K2, K6C, K4, K13, K31, and K15-specific to OM epithelial cells-were significantly lower in the experimental NCSCs. While SOX10 was decreased with no statistically significant difference, the earliest neural crest specifier genes SNAI1/2, Ap2a, Ap2c, SOX9, SOX30, Pax3, and Twist1 showed a trend in increased expression in NCSCs. In addition, proteins of Oct4, Nestin and Noth1 were found to be greatly expressed, confirming NCSC multipotency. In conclusion, our study showed that the epithelium of OM contains NCSCs that can be isolated and expanded with clinical-grade reagents to supply the demand for multipotent cells required for clinical applications in regenerative medicine. Supported by Emmaus Medical Inc.

A Temporospatial Study of Sympathetic Skin Response and Electroencephalogram in Oral Mucosa Thermal Perception

Objective

To investigate the temporospatial changes in sympathetic skin response (SSR) and electroencephalogram (EEG) under thermal stimuli and to draw a topographic map of SSR threshold temperature of the oral mucosa.

Materials and Methods

A total of 40 healthy volunteers (24 men, 16 women, mean age of 23 ± 3) were enrolled. Thermal stimuli were applied to the 35 partitions of oral mucosa starting from 36°C at the gradience of 1°C and the lowest temperature evoked SSR was defined as SSR threshold temperature. SSR and EEG signals at 45, 48, 51, and 54°C were then recorded synchronously.

Results

The SSR threshold temperature increased from the anterior areas to the posterior areas. No significant difference between bilateral corresponding areas or between genders was observed. The SSR amplitude value increased from 45 to 54°C in the same area, while the highest value was recorded on the tip of the tongue and decreased backwardly from the anterior area. There were significant differences in latency of SSR between the tip of the tongue and the molar areas of the oral cavity (p < 0.05). Reduction in the alpha frequency band was observed after thermal stimuli, and there were statistical differences between baseline and thermal stimuli in all four degrees of temperatures (p < 0.05).

Conclusion

The result of the experiment revealed that the autonomic and central nervous system (CNS) played important roles in thermal perception of oral mucosa and could be helpful for better understanding of pathological mechanism of burning mouth syndrome (BMS).

Autophagy in aging-related oral diseases

Autophagy is an intracellular degradation mechanism that allows recycling of organelles and macromolecules. Autophagic function increases metabolite availability modulating metabolic pathways, differentiation and cell survival. The oral environment is composed of several structures, including mineralized and soft tissues, which are formed by complex interactions between epithelial and mesenchymal cells. With aging, increased prevalence of oral diseases such as periodontitis, oral cancer and periapical lesions are observed in humans. These aging-related oral diseases are chronic conditions that alter the epithelial-mesenchymal homeostasis, disrupting the oral tissue architecture affecting the quality of life of the patients. Given that autophagy levels are reduced with age, the purpose of this review is to discuss the link between autophagy and age-related oral diseases.

Can Human Oral Mucosa Stem Cells Differentiate to Corneal Epithelia?

Human oral mucosa stem cells (hOMSCs) arise from the neural crest, they can self-renew, proliferate, and differentiate to several cell lines and could represent a good source for application in tissue engineering. Because of their anatomical location, hOMSCs are easy to isolate, have multilineage differentiation capacity and express embryonic stem cells markers such as—Sox2, Oct3/4 and Nanog. We have used SHEM (supplemented hormonal epithelial medium) media and cultured hOMSCs over human amniotic membrane and determined the cell’s capacity to differentiate to an epithelial-like phenotype and to express corneal specific epithelial markers—CK3, CK12, CK19, Pan-cadherin and E-cadherin. Our results showed that hOMSCs possess the capacity to attach to the amniotic membrane and express CK3, CK19, Pan-Cadherin and E-Cadherin without induction with SHEM media and expressed CK12 or changed the expression pattern of E-Cadherin to a punctual-like feature when treated with SHEM media. The results observed in this study show that hOMSCs possess the potential to differentiate toward epithelial cells. In conclusion, our results revealed that hOMSCs readily express markers for corneal determination and could provide the ophthalmology field with a therapeutic alternative for tissue engineering to achieve corneal replacement when compared with other techniques. Nevertheless, further studies are needed to develop a predictable therapeutic alternative for cornea replacement.

Clinical features of post-radiation nasopharyngeal necrosis and their outcomes following surgical intervention in nasopharyngeal cancer patients

PURPOSE

To investigate the incidence and clinical features of post-radiation nasopharyngeal necrosis (PRNN), and effectiveness of surgical intervention for its treatment.

MATERIALS AND METHODS

Retrospectively, we reviewed 380 NPC patients who underwent high dose radiotherapy (RT) (single RT in 355 and re-RT in 25) from January 2008 till December 2017 at the authors' institute, among who 22 developed Grade ≥ 3 PRNN. The management of PRNN was discussed through weekly multidisciplinary head and neck oncology conference, and surgical debridement was performed when feasible.

RESULTS

The incidence of PRNN was significantly higher following re-RT than in single RT (11/355, 3.1% vs. 11/25, 44.0%, p < 0.001). The PRNN patients in single RT group tended to be older and had more advanced initial tumor extents. The intervals from the latest RT start till PRNN assignment were similar between groups (7.3 vs. 6.6 months, p = 0.140). Nineteen patients underwent surgical debridement: two open; and 17 endoscopic approach, respectively. Endoscopic mucosal reconstruction was performed in eight patients. Resolution of PRNN was achieved in 11 patients (64.7%). The rates of 3-year overall survivals (OS) from the initial RT, latest RT (adjusting re-RT), and PRNN assignment were 84.4%, 70.9%, and 54.7%, respectively. Eight patients (36.4%) succumbed to death: NPC progression in three (13.6%); evidently PRNN-related events in two (9.1%), probably PRNN-related events in two (9.1%); and inter-current death in one (4.5%), respectively.

CONCLUSION

PRNN needs close collaboration among head and neck oncologists and could be successfully recovered, without compromising survival, following timely surgical intervention.

The progress in corneal translational medicine

Cornea tissue is in high demand by tissue donation centres globally, and thus tissue engineering cornea, which is the main topic of corneal translational medicine, can serve as a limitless alternative to a donated human cornea tissue. Tissue engineering aims to produce solutions to the challenges associated with conventional cornea tissue, including transplantation and use of human amniotic membrane (HAM), which have issues with storage and immune rejection in patients. Accordingly, by carefully selecting biomaterials and fabrication methods to produce these therapeutic tissues, the demand for cornea tissue can be met, with an improved healing outcome for recipients with less associated harmful risks. In this review paper, we aim to present the recent advancements in the research and clinical applications of cornea tissue, applications including biomaterial selection, fabrication methods, scaffold structure, cellular response to these scaffolds, and future advancements of these techniques.

Cellular ageing of oral fibroblasts differentially modulates extracellular matrix organization

BACKGROUND AND OBJECTIVES

Ageing is associated with an impaired cellular function that can affect tissue architecture and wound healing in gingival and periodontal tissues. However, the impact of oral fibroblast ageing on the structural organization of the extracellular matrix (ECM) proteins is poorly understood. Hence, in this study, we investigated the impact of cellular ageing of oral fibroblasts on the production and structural organization of collagen and other ECM proteins.

METHODS

Oral fibroblasts were serially subcultured, and replicative cellular senescence was assessed using population doubling time, Ki67 counts and expression of P21^WAFI . The production and structural organization of ECM proteins were assessed at early (young-oFB) and late (aged-oFB) passages. The thickness and pattern of collagen produced by live cultures of young- and aged-oFB were assessed using a label-free and non-invasive second harmonic generation (SHG)-based multiphoton imaging. Expression of other ECM proteins (fibronectin, fibrillin, collagen-IV and laminins) was evaluated using immunocytochemistry and confocal microscopy-based depth profile analysis.

RESULTS

Aged-oFB displayed a higher population doubling time, lower Ki67+ cells and higher expression of P21^WAFI indicative of slower proliferation rate and senescence phenotype. SHG imaging demonstrated that young-oFB produced a thick, interwoven network of collagen fibres, while the aged-oFB produced thin and linearly organized collagen fibres. Similarly, analysis of immunostained cultures showed that young-oFB produced a rich, interwoven mesh of fibronectin, fibrillin and collagen-IV fibres. In contrast, the aged-oFB produced linearly organized fibronectin, fibrillin and collagen-IV fibres. Lastly, there was no observable difference in production and organization of laminins among the young- and aged-oFB.

CONCLUSION

Our results suggest that oral fibroblast ageing impairs ECM production and more importantly the organization of ECM fibres, which could potentially impair wound healing in the elderly.

Prevalence of Oral Mucosal Lesions Among the Institutionalized Elderly Population in Lebanon

This study aimed to determine the prevalence of oral mucosal lesions and risk factors among the institutionalized elderly Lebanese population. A representative sample of 526 individuals (49% males and 61% females) aged 65 years and above was examined. A questionnaire and clinical examination were administered. Bivariate and multivariate regressions were carried out. The frequency of oral mucosal lesions was 22.8% and it was associated to the use, integrity (p < .002), and hygiene level (p < .047) of removable mandibular and maxillary prosthesis. Multiple regression analysis also predicted the relationship between the mandibular prosthesis hygiene level and the occurrence of mucosal lesions. The factors controlling the occurrence of oral mucosal lesion were mainly related to the level of oral care given to the individuals. Therefore, a proper oral health care system should be implemented in the Lebanese residential homes to ensure the well-being of the residing population.

COMPARISON OF EXPRESSION OF E-CADHERIN IN ORAL PSEUDOEPITHELIOMATOUS HYPERPLASIA AND ORAL SQUAMOUS CELL CARCINOMA

Background: Pseudo-epitheliomatous Hyperplasia (PEH) is a benign proliferation of epithelium occurring in response to various neoplastic lesions, infections and inflammatory processes. It can be mistaken especially in small biopsies for an invasive oral squamous cell carcinoma (OSCC). The objective of this study was to determine the expression and comparison of immunohistochemical marker E-cadherin in OSCC and PEH lesions. Materials & Methods: This cross-sectional study was conducted in Department of Histopathology, Armed Forces Institute of Pathology, Rawalpindi, Pakistan from January 2013 to March 2016. 60 paraffin embedded cases, 30 each of PEH and OSCC were retrieved and stained with haematoxylin and eosin. They were then immune-stained with E-cadherin and expression evaluated and compared in two lesions by histopathologist. Age, sex, site of lesion and E-cadherin expression were variables. Age was described by mean and SD and other variables as frequency and percentages. Results: Mean age of OSCC group was 60.1±17.3 years and PEH group 52.7±16.6 years. OSCC group included 16 (53.33%) men and 14 (46.67%) women. PEH group included 18 (60%) men and 12 (40%) women. In OSCC group, site of lesion was buccal mucosa 12 (40%) cases, gingiva 10 (33.3%), tongue 7 (23.3%) and floor of mouth 1 (3.4%) case. In PEH group, site of lesion was buccal mucosa 12 (40%) cases, tongue 11 (36.67%), gingiva 6 (20%) and palate 1 (3.3%) case. The expression of E-cadherin was negative in all 30 cases of OSCC and positive in 29/30 (96.67%) cases in PEH. Conclusion: E-cadherin can be used as an ancillary marker in the differentiation of oral squamous cell carcinoma and pseudo-epitheliomatous hyperplasia.

Evaluation of treatment response in oral chronic graft-versus-host patients by power doppler ultrasound: a prospective study

OBJECTIVE

To date, imaging and non-invasive examination methods for evaluating the oral tissue of patients who with oral chronic graft-versus-host disease (GVHD) are still lacking. Herein, we assessed the ultrasonography imaging characteristics of chronic GVHD patients' buccal soft tissue and evaluated the response to treatment using gray-scale and power Doppler (PD) ultrasound. The overall objective of the study was to determine the potential of ultrasonography to provide an early and objective indication of a therapeutic response to treatment intervention in oral chronic GVHD.

METHODS

Buccal mucosa in 21 patients with clinically diagnosis of oral chronic GVHD were assessed before and after 14 day treatment between 2016 and 2018. Ultrasonography assessment included thickness and echogenicity evaluation, and PD. Echogenicity and PD were measured and scored according to a semi-quantitative method. Ultrasonography parameters were compared with clinical activity assessments of disease activity and patient-reported measures.

RESULTS

Following 14 day therapy, a significant decrease in PD scores and patient-reported measures was observed (p < 0.01), and clinical assessment scores also decreased (p < 0.05). Changes from baseline PD scores correlated significantly with patient-reported measures (r = 0.85, p < 0.01). Changes in PD scores correlated moderately with the changes in the clinical assessments from baseline (r = 0.46, p < 0.05). A significant decrease in PD scores was observed in the buccal soft tissue of patients that responded clinically to the treatment. A significant decrease in PD scores was also observed in patients that were failed to show clinical improvement (p < 0.05).

CONCLUSION

Ultrasonography is a novel and feasible imaging technique for measurement of the response of oral chronic GVHD to therapy. Ultrasonography yields additional information about buccal mucosa and is a complementaty to clinical examination.

Clinical Trials of Limbal Stem Cell Deficiency Treated with Oral Mucosal Epithelial Cells

The corneal surface is an essential organ necessary for vision, and its clarity must be maintained. The corneal epithelium is renewed by limbal stem cells, located in the limbus and in palisades of Vogt. Palisades of Vogt maintain the clearness of the corneal epithelium by blocking the growth of conjunctival epithelium and the invasion of blood vessels over the cornea. The limbal region can be damaged by chemical burns, physical damage (e.g., by contact lenses), congenital disease, chronic inflammation, or limbal surgeries. The degree of limbus damage is associated with the degree of limbal stem cells deficiency (partial or total). For a long time, the only treatment to restore vision was grafting part of the healthy cornea from the other eye of the patient or by transplanting a cornea from cadavers. The regenerative medicine and stem cell therapies have been applied to restore normal vision using different methodologies. The source of stem cells varies from embryonic stem cells, mesenchymal stem cells, to induced pluripotent stem cells. This review focuses on the use of oral mucosa epithelial stem cells and their use in engineering cell sheets to treat limbal stem cell deficient patients.

Stomatological disorders in older people: An epidemiological study in the Brazil southern

BACKGROUND

The aim of this retrospective, cross-sectional and observational study was to perform a survey of the stomatological conditions of elderly patients seen in a period of 40 years at a Stomatology Service in Southern Brazil.

MATERIAL AND METHODS

A total of 24,347 medical records were reviewed, of which 5,063 belonged to elderly patients aged 60 to 97 years. The stomatological conditions, systemic conditions, and smoking and alcohol drinking habits as well were recorded.

RESULTS

The mean age of the patients was 69.29 years, 67.1% were female and 32.9% were male. Variations of normality accounted for 44.5% of the cases. The most prevalent disorders were fungal infections (26.1%), reactive inflammatory lesions (24.6%), burning mouth syndrome (14.9%), benign neoplasms (12.4%), autoimmune disorders (12.3%), premalignant lesions (10.2%) and malignant epithelial neoplasms (7.2%). Regarding biopsied lesions, squamous cell carcinoma was the most prevalent at 30.2%, followed by hyperplasic lesions (28.2%).

CONCLUSIONS

Knowledge of these physiological and pathological conditions in the oral cavity of the older people is essential for early diagnosis and preventive and therapeutic measures when necessary.

Challenges in the local delivery of peptides and proteins for oral mucositis management

Oral mucositis, a common inflammatory side effect of oncological treatments, is a disorder of the oral mucosa that can cause painful ulcerations, local motor disabilities, and an increased risk of infections. Due to the discomfort it produces and the associated health risks, it can lead to cancer treatment restrains, such as the need for dose reduction, cycle delays or abandonment. Current mucositis management has low efficiency in prevention and treatment. A topical drug application for a local action can be a more effective approach than systemic routes when addressing oral cavity pathologies. Local delivery of growth factors, antibodies, and anti-inflammatory cytokines have shown promising results. However, due to the peptide and protein nature of these novel agents, and the several anatomic, physiological and environmental challenges of the oral cavity, their local action might be limited when using traditional delivering systems. This review is an awareness of the issues and strategies in the local delivery of macromolecules for the management of oral mucositis.

Factors Affecting the Occurrence of Complications in the Early Stages After Dental Implant Placement: A Retrospective Cohort Study

OBJECTIVE

To evaluate the background factors related to the occurrence of complications in the early stages after dental implant placement.

MATERIALS AND METHODS

A total of 289 outpatients who received dental implants were retrospectively evaluated for the presence or absence of complications. Background factors, including age, sex, implant width, implant length, implant site, number of implants placed, Periotest values at the time of implant placement, presence/absence of systemic disease (particularly diabetes), and the use of anticoagulation therapy, were compared between patients with and without complications. Logistic regression analysis was performed to identify significant risk factors for the occurrence of complications after dental implant placement.

RESULTS

Complications in the early stages after dental implant placement occurred in 25 (8.65%) patients. The patients with complications were older than those without complications (P = 0.003). In addition, the incidence of complications was significantly higher in patients with systemic diseases (P = 0.004) and in those receiving anticoagulation therapy (P = 0.005). Logistic regression analysis revealed that age was a significant risk factor (P = 0.025) for early-stage complications, whereas the number of implants, presence of diabetes, and the use of anticoagulation therapy were not significant risk factors.

CONCLUSIONS

Our results show that age is a significant factor influencing the occurrence of complications in the early stages after dental implant placement. Therefore, clinicians should consider this factor when developing their treatment strategies.

Incidence and risk factors for postoperative lingual neuropraxia following airway instrumentation: A retrospective matched case-control study

Background

Lingual nerve injury or neuropraxia is a rare but potentially serious perioperative complication following airway instrumentation during general anesthesia. This study explored the the incidence and perioperative risk factors for lingual nerve injury in patients receiving laryngeal mask (LMA) or endotracheal (ETGA) general anesthesia in a single center experience.

Methods and results

All surgical patients in our hospital who received LMA or ETGA from 2009 to 2013 were included, and potential perioperative risk factors were compared. Matched controls were randomly selected (in 1:5 ratio) from the same database in non-case patients. A total of 36 patients in the records had reported experiencing tongue numbness after anesthesia in this study. Compared with the non-case surgical population (n = 54314), patients with tongue numbness were significantly younger (52.2±19.5 vs 42.0±14.5; P = 0.002) and reported lower ASA physical statuses (2.3±0.7 vs 1.6±0.6; P<0.001). Patient gender, anesthesia technique used, and airway device type (LMA or ETGA) did not differ significantly across the two groups. A significantly higher proportion of patients underwent operations of the head-and-neck region (38.9 vs 15.6%; P = 0.002) developed tongue numbness after anesthesia. Multivariate logistic regression analysis indicated that head-and-neck operations remained the most significant independent risk factor for postoperative lingual nerve injury (AOR 7.63; 95% CI 2.03–28.70).

Conclusion

The overall incidence rate of postoperative lingual neuropraxy was 0.066% in patients receiving general anesthesia with airway device in place. Young and generally healthy patients receiving head-and-neck operation are at higher risk in developing postoperative lingual neuropraxy. Attention should be particularly exercised to reduce the pressure of endotracheal tube or laryngeal mask on the tongue during head-and-neck operation to avert the occurrence of postoperative lingual neuropraxy.

Assessment of lingual nerve functions after smoking cessation

OBJECTIVE

Cigarette smoking is associated with a variety of oral diseases. A previous study showed a reduction of thermal sensitivity in the innervation area of the lingual nerve in smokers possibly caused by a degeneration of thermosensitive receptors as a consequence of smoking. The current study investigates somatosensory changes in ex-smokers.

MATERIALS AND METHODS

Sensory functions in innervation areas of lingual nerve were investigated in 40 ex-smokers by psychophysical means. Functions of lingual nerve in 40 ex-smokers were compared to those in 40 smokers and 40 non-smokers. Subjects were investigated using quantitative sensory testing (QST, cold and warm detection, thermal sensory limen, heat and cold pain, and mechanical detection).

RESULTS

Significant differences were found in both groups, ex-smokers and smokers compared to non-smokers. Cold (p < .001), warm (ex-smokers: p < .01; smokers: p < .001) detection thresholds and thermal sensory limen (p < .001) showed significantly lower sensitivity in ex-smokers and smokers in comparison to non-smokers.

CONCLUSIONS

The lower temperature sensitivity of ex-smokers compared to that in non-smokers indicates a reduction of somatosensory function of the tongue, possibly caused by irreversible nerve degeneration associated with smoking. Influencing factors leading to sensory changes could be modulation of thermo-receptors, demyelination as well as a change of the epithelial structure.

Oligohydramnios compromises lung cells size and interferes with epithelial-endothelial development

BACKGROUND AND OBJECTIVE

Severe oligohydramnios can induce pulmonary hypoplasia. However, the mechanisms by which leaking of fluids cause lung hypoplasia are not well defined. The objective of this study was to characterize a mouse model of pulmonary hypoplasia induced by oligohydramnios.

METHODS

Amniotic sacs were punctured on E14.5 of gestation. Untouched fetuses were used as control. Pregnancy was allowed to continue until E18.5 in which lung tissue was collected and evaluated for morphometry, proliferation, differentiation, apoptosis, and angiogenesis.

RESULTS

Our results found that lung weight, lung to total body weight ratio, and lung water content were reduced in oligohydramnios when compared to controls. In contrast, oligohydramnios did not affect the DNA content. Morphometric studies confirmed that oligohydramnios fetuses had smaller air spaces than control. Interestingly, cells from oligohydramnios fetuses have smaller size and less regular shapes. Oligohydramnios decreased the differentiation of type I epithelial cells and compromised apoptosis and angiogenesis while proliferation was not affected.

CONCLUSIONS

Although, the smaller size of the lung could be explained by a decreased of lung fluids, our data suggest that increased of external compression secondary to severe oligohydramnios can compromise cell size and interfere with epithelial and endothelial development. Type I epithelial cells could have an unrecognized key role in the differentiation of the distal lung mediated by mechanical signals. Pediatr Pulmonol. 2017;52:746-756. © 2017 Wiley Periodicals, Inc.

HIV Infection and Compromised Mucosal Immunity: Oral Manifestations and Systemic Inflammation

Mucosal surfaces account for the vast majority of HIV transmission. In adults, HIV transmission occurs mainly by vaginal and rectal routes but rarely via oral route. By contrast, pediatric HIV infections could be as the result of oral route by breastfeeding. As such mucosal surfaces play a crucial role in HIV acquisition, and spread of the virus depends on its ability to cross a mucosal barrier. HIV selectively infects, depletes, and/or dysregulates multiple arms of the human immune system particularly at the mucosal sites and causes substantial irreversible damage to the mucosal barriers. This leads to microbial products translocation and subsequently hyper-immune activation. Although introduction of antiretroviral therapy (ART) has led to significant reduction in morbidity and mortality of HIV-infected patients, viral replication persists. As a result, antigen presence and immune activation are linked to “inflammaging” that attributes to a pro-inflammatory environment and the accelerated aging process in HIV patients. HIV infection is also associated with the prevalence of oral mucosal infections and dysregulation of oral microbiota, both of which may compromise the oral mucosal immunity of HIV-infected individuals. In addition, impaired oral immunity in HIV infection may predispose the patients to periodontal diseases that are associated with systemic inflammation and increased risk of cardiovascular diseases. The purpose of this review is to examine existing evidence regarding the role of innate and cellular components of the oral cavity in HIV infection and how HIV infection may drive systemic hyper-immune activation in these patients. We will also discuss current knowledge on HIV oral transmission, HIV immunosenescence in relation to the oral mucosal alterations during the course of HIV infection and periodontal disease. Finally, we discuss oral manifestations associated with HIV infection and how HIV infection and ART influence the oral microbiome. Therefore, unraveling how HIV compromises the integrity of the oral mucosal tissues and innate immune components of the oral cavity and its association with induction of chronic inflammation are critical for the development of effective preventive interventions and therapeutic strategies.

HIV Infection and Compromised Mucosal Immunity: Oral Manifestations and Systemic Inflammation

Mucosal surfaces account for the vast majority of HIV transmission. In adults, HIV transmission occurs mainly by vaginal and rectal routes but rarely via oral route. By contrast, pediatric HIV infections could be as the result of oral route by breastfeeding. As such mucosal surfaces play a crucial role in HIV acquisition, and spread of the virus depends on its ability to cross a mucosal barrier. HIV selectively infects, depletes, and/or dysregulates multiple arms of the human immune system particularly at the mucosal sites and causes substantial irreversible damage to the mucosal barriers. This leads to microbial products translocation and subsequently hyper-immune activation. Although introduction of antiretroviral therapy (ART) has led to significant reduction in morbidity and mortality of HIV-infected patients, viral replication persists. As a result, antigen presence and immune activation are linked to "inflammaging" that attributes to a pro-inflammatory environment and the accelerated aging process in HIV patients. HIV infection is also associated with the prevalence of oral mucosal infections and dysregulation of oral microbiota, both of which may compromise the oral mucosal immunity of HIV-infected individuals. In addition, impaired oral immunity in HIV infection may predispose the patients to periodontal diseases that are associated with systemic inflammation and increased risk of cardiovascular diseases. The purpose of this review is to examine existing evidence regarding the role of innate and cellular components of the oral cavity in HIV infection and how HIV infection may drive systemic hyper-immune activation in these patients. We will also discuss current knowledge on HIV oral transmission, HIV immunosenescence in relation to the oral mucosal alterations during the course of HIV infection and periodontal disease. Finally, we discuss oral manifestations associated with HIV infection and how HIV infection and ART influence the oral microbiome. Therefore, unraveling how HIV compromises the integrity of the oral mucosal tissues and innate immune components of the oral cavity and its association with induction of chronic inflammation are critical for the development of effective preventive interventions and therapeutic strategies.

Buccal Dosage Forms: General Considerations for Pediatric Patients

The development of an appropriate dosage form for pediatric patients needs to take into account several aspects, since adult drug biodistribution differs from that of pediatrics. In recent years, buccal administration has become an attractive route, having different dosage forms under development including tablets, lozenges, films, and solutions among others. Furthermore, the buccal epithelium can allow quick access to systemic circulation, which could be used for a rapid onset of action. For pediatric patients, dosage forms to be placed in the oral cavity have higher requirements for palatability to increase acceptance and therapy compliance. Therefore, an understanding of the excipients required and their functions and properties needs to be particularly addressed. This review is focused on the differences and requirements relevant to buccal administration for pediatric patients (compared to adults) and how novel dosage forms can be less invasive and more acceptable alternatives.

Effects of C-xylopyranoside derivative on epithelial regeneration in an in vitro 3D oral mucosa model

Identifying substandard tissue-engineered oral mucosa grafts with a poor epithelium before clinical use is critical to ensure quality assurance/control in regenerative medicine, leading to success of grafting. This study investigated the effects of one of the C-xylopyranoside derivatives, β-D-xylopyranoside-n-propane-2-one (XPP), on oral epithelial regeneration. Using a three-dimensional oral mucosa model, we analyzed changes of the epithelial structure, glycosaminoglycan (GAG) synthesis, the expression levels of basement membrane zone markers, and substrates of Akt/mTOR signaling. Compared with the control, 2 mM XPP treatment increased the mean and minimal epithelial thickness, and reduced the variation of epithelial thickness. It also stimulated expressions of decorin and syndecan-1 with change of GAG amount and/or composition, and enhanced the expressions of integrin α6, CD44, and Akt/mTOR signaling substrates. These findings suggest that XPP supplementation contributes to consistent epithelial regeneration. Moreover, upregulation of those markers may play a role in increasing the quality of the oral mucosal epithelium.

Regional quantitative histological variations in human oral mucosa

Oral mucosa demonstrates regional variations that reflect contact with food during mastication. Though known qualitatively, our aim was to quantitatively assess regions to establish a measurable baseline from which one could compare in pathological and comparative studies, in which the abrasiveness of diets may differ. We assessed variations in the epithelial-connective tissue junction (rete ridges counts), collagen organization within the lamina propria, and elastin composition of the lamina propria of 15 regions of the labial (buccal) gingiva, lingual gingiva, vestibule, and palate. All characteristics varied more between regions within the same individual than between individuals. Lingual gingiva had high rete ridges counts, high level of collagen organization, and moderate elastin composition compared to other regions. The labial gingiva had few rete ridges, high collagen organization, and low elastin. The vestibule had the fewest average of rete ridges, least organized collagen, and high elastin. The hard palate had the highest average of rete ridges, high collagen organization, and the lowest elastin content. The soft palate conversely had the smallest average of rete ridges, moderate collagen organization, and the highest elastin composition. Our results indicate that comparison of these quantitative histological differences is warranted only for collagen organization and elastin composition. Differences in rete ridges counts were not statistically significant. Most histological characteristics observed were not significantly different between dentulous and edentulous cadavers, and the group containing all individuals. An exception was the level of collagen fiber organization within the lamina propria, which was higher in most regions when teeth were present.

Ultrasonographic evaluation of oral submucous fibrosis in habitual areca nut chewers

OBJECTIVES

To characterize the sonographic features of the buccal mucosa in patients with oral submucous fibrosis (OSF).

METHODS

Three groups (controls with areca-related habits, controls without areca-related habits and clinically diagnosed OSF cases), each comprising 30 subjects, were included in the study. After a thorough clinical examination, transcutaneous B-mode ultrasonography was performed with a multifrequency linear transducer (5-10 MHz) for anterior and posterior buccal mucosa bilaterally. Both clinical and ultrasound findings were recorded by three independent observers. One-way analysis of variance and Tukey's honestly significant difference post-hoc tests were used for statistical comparisons between groups and Pearson χ(2) tests to compare the proportions. Kappa statistics was used to determine the interobserver agreement.

RESULTS

The submucosa that appeared hypoechoic in the control groups had significantly increased echogenicity in the case group (hypo- to isoechoic in 46.7% and isoechoic in 53.3%). The differentiation between the submucosa and the muscle layer appeared distinct in the control groups while it was not clear in the case group (indistinct in 50% and completely lost in 50%). The number of sites found positive on the ultrasound was significantly greater than the number of clinically positive sites. There was a very good interobserver consistency in clinical and ultrasound findings.

CONCLUSIONS

Ultrasonography of the buccal mucosa demonstrates increased submucosal echogenicity and reduced echo differentiation between submucosa and muscle layer in OSF cases. Hence, it can be used as a non-invasive imaging modality to assess the disease extent and severity across the entire buccal mucosa to supplement clinical evaluation.