Vitamin D Deficiency as It Relates to Oral Immunity and Chronic Periodontitis

The biologically active form of vitamin D, 1,25 dihydroxyvitamin D (1,25(OH)2D) and its receptor, the vitamin D receptor (VDR), play roles in maintaining oral immunity and the integrity of the periodontium. Results of observational cross-sectional clinical studies investigating the association between vitamin D serum level and the incidence and severity of chronic periodontitis indicate that, perhaps owing to the immunomodulatory, anti-inflammatory, and antibacterial properties of 1,25(OH)2 D/VDR signalling, a sufficient serum level of vitamin D is necessary for the maintenance of periodontal health. In cases of established chronic periodontitis, vitamin D supplementation is associated with reduction in the severity of periodontitis. As cross-sectional studies provide only weak evidence for any causal association and therefore are of questionable value, either longitudinal cohort studies, case controlled studies, or randomized control trials are needed to determine whether or not deficiency of vitamin D is a risk factor for chronic periodontitis, and whether or not vitamin D supplementation adjunctive to standard periodontal treatment is in any way beneficial. In this article, we discuss the relationship between vitamin D, oral immunity and periodontal disease and review the rationale for using vitamin D supplementation to help maintain periodontal health and as an adjunct to standard periodontal treatment.

Oral manifestations of thrombocytopaenia

The appearance in the mouth of haemorrhagic petechiae, ecchymoses or blood blisters with spontaneous bleeding is suggestive of a haemorrhagic disorder that may be caused either by functional impairment of platelets or of blood vessel walls, by an abnormal decrease in the number of circulating platelets (thrombocytopaenia), or by defects in the blood clotting mechanism. Thrombocytopaenia from decreased production or increased destruction of platelets may be caused by multiple factors including immune mediated mechanisms, drugs or infections.

A diagnosis of thrombocytopaenic purpura can be made when any other disease entity that might be causing the purpura is excluded on the basis of the medical history, the physical examination, a complete blood count and a peripheral blood smear.

In this paper, we outline the clinical features of oral thrombocytopaenic purpura and briefly discuss some aspects of its aetiopathogenesis and treatment.

The Biological Activities of Vitamin D and Its Receptor in Relation to Calcium and Bone Homeostasis, Cancer, Immune and Cardiovascular Systems, Skin Biology, and Oral Health

Vitamin D plays an important role in calcium homeostasis and bone metabolism, with the capacity to modulate innate and adaptive immune function, cardiovascular function, and proliferation and differentiation of both normal and malignant keratinocytes. 1,25(OH)2D, the biologically active form of vitamin D, exerts most of its functions through the almost universally distributed nuclear vitamin D receptor (VDR). Upon stimulation by 1,25(OH)2D, VDR forms a heterodimer with the retinoid X receptor (RXR). In turn, VDR/RXR binds to DNA sequences termed vitamin D response elements in target genes, regulating gene transcription. In order to exert its biological effects, VDR signalling interacts with other intracellular signalling pathways. In some cases 1,25(OH)2D exerts its biological effects without regulating either gene expression or protein synthesis. Although the regulatory role of vitamin D in many biological processes is well documented, there is not enough evidence to support the therapeutic use of vitamin D supplementation in the prevention or treatment of infectious, immunoinflammatory, or hyperproliferative disorders. In this review we highlight the effects of 1,25(OH)2D on bone and calcium homeostasis, on cancer, and refer to its effects on the cardiovascular and immune systems.

Postherpetic Neuralgia and Trigeminal Neuralgia

Postherpetic neuralgia (PHN) is an unpredictable complication of varicella zoster virus- (VZV-) induced herpes zoster (HZ) which often occurs in elderly and immunocompromised persons and which can induce psychosocial dysfunction and can negatively impact on quality of life. Preventive options for PHN include vaccination of high-risk persons against HZ, early use of antiviral agents, and robust management of pain during the early stage of acute herpes zoster. If it does occur, PHN may persist for months or even years after resolution of the HZ mucocutaneous eruptions, and treatment is often only partially effective. Classical trigeminal neuralgia is a severe orofacial neuropathic pain condition characterized by unilateral, brief but recurrent, lancinating paroxysmal pain confined to the distribution of one or more of the branches of the trigeminal nerve. It may be idiopathic or causally associated with vascular compression of the trigeminal nerve root. The anticonvulsive agents, carbamazepine or oxcarbazepine, constitute the first-line treatment. Microvascular decompression or ablative procedures should be considered when pharmacotherapy is ineffective or intolerable. The aim of this short review is briefly to discuss the etiopathogenesis, clinical features, and treatment of PHN and classical trigeminal neuralgia.

Oral mucosal melanoma: some pathobiological considerations and an illustrative report of a case

Oral mucosal melanoma is a relatively rare malignancy with an aggressive clinico-pathological behaviour. The mean 5-year survival rate is about 15 %. It arises primarily from melanocytes found in the basal cell layer of the epithelium, but may sometimes arise from melanocytes residing in the lamina propria. The pathogenesis is complex, and few of the molecular mechanisms underlying the development of oral mucosal melanoma have been defined. The extraneous risk factors associated with oral mucosal melanoma, if any, are unknown. Oral mucosal melanomas account for about 25 % of all mucosal melanomas of the head and neck, and exhibit a profile of cytogenetic alterations, and a pathobiological behaviour and clinical course different from that of cutaneous melanomas. As they are usually painless and grow quickly, as a rule, they are diagnosed late in the course of the disease when the lesions are already large and have metastasized to regional lymph nodes. In this paper we discuss some aspects of the pathobiology of oral mucosal melanoma, and present an illustrative case report.

Oral medicine case book 65: Necrotising stomatitis

Necrotising stomatitis is a fulminating anaerobic polybacterial infection affecting predominantly the oral mucosa of debilitated malnourished children or immunosuppressed HIV-seropositive subjects. It starts as necrotising gingivitis which progresses to necrotising periodontitis and subsequently to necrotising stomatitis. In order to prevent the progression of necrotising stomatitis to noma (cancrum oris), affected patients should be vigorously treated and may require admission to hospital. Healthcare personnel should therefore be familiar with the signs and symptoms of necrotising gingivitis/necrotising periodontitis, of their potential sequelae and of the need for immediate therapeutic intervention.

Oral medicine case book 64: Some aspects of the pathophysiology of angioedema with special reference to the upper aerodigestive tract

Angioedema refers to a localized oedematous swelling of subcutaneous or submucosal tissues, caused by dilatation and increased permeability of blood vessels, usually mediated either by histamine or by bradykinin. Deficiency or loss of functional activity of the complement component C1 esterase inhibitor (C1-INH) affects multiple systems, including the kallikrein-kinin, complement, coagulation and fibrinolytic pathways, and in the context of angioedema, the result is increased production and release of bradykinin and other vasoactive substances such as C3a. Owing to impairment of C1-INH, factors Xlla and kallikrein, by a positive feedback mechanism, bring about persistent activation of the kallikrein-kinin pathway with amplification of production of bradykinin, resulting in angioedema. Histamine can cause histaminergic angioedema. As the name implies, this oedema is caused by degranulation of mast cells/basophils as a result of an IgE-dependant allergic reaction to extracts of food, drugs, infectious agents, or to physical stimulation; or as the result of direct degranulation of mast cells/basophils independently of IgE, caused by releasing agents such as opiates, antibiotics or radiocontrast media. As dental, oral and maxillofacial operative procedures may trigger the development of angioederria in susceptible individuals, the dental practitioner should be familiar with its

Race/ethnicity in biomedical research and clinical practice

There is ongoing debate as to whether persons of different racial/ethnic groups are biologically significantly different, and, if such differences exist, whether they are relevant in relation to disease susceptibility and to treatment outcomes. There is also debate about the benefits of using race/ethnicity as a factor in clinical decision making, and as a variable in biomedical or public health research, because of the emotional sensitivities attached to race/ethnic categorisation. Such categorisation may also divert attention from underlying issues such as socioeconomic status and lack of access to modern health care. In this short article we will discuss these controversies, and will emphasize the importance of responsible and sensitive use of race/ethnicity as a variable in biomedical research and in clinical practice.

Osseointegration: biological events in relation to characteristics of the implant surface

Osseointegration of titanium implants is a complex biological process involving interactions between immuno-inflammatory responses, angiogenesis and osteogenesis, all of which are influenced by the physical and chemical characteristics of the implant surface. An implant surface with moderately rough topography and high surface energy influences cellular activities, enhancing peri-implant bone wound healing. Primary mechanical stability of the implant is essential for osseointegration. In this article we review some of the more important biological events of peri-implant bone wound healing in the process of osseointegration, and discuss how the biophysical properties of implant surfaces influence cellular responses.

Oral candidosis in relation to oral immunity

Symptomatic oral infection with Candida albicans is characterized by invasion of the oral epithelium by virulent hyphae that cause tissue damage releasing the inflammatory mediators that initiate and sustain local inflammation. Candida albicans triggers pattern-recognition receptors of keratinocytes, macrophages, monocytes and dendritic cells, stimulating the production of IL-1β, IL-6 and IL-23. These cytokines induce the differentiation of Th17 cells and the generation of IL-17- and/or IL-22-mediated antifungal protective immuno-inflammatory responses in infected mucosa. Some immune cells including NKT cells, γδ T cells and lymphoid cells that are innate to the oral mucosa have the capacity to produce large quantities of IL-17 in response to C. albicans, sufficient to mediate effective protective immunity against C. albicans. On the other hand, molecular structures of commensal C. albicans blastoconidia, although detected by pattern-recognition receptors, are avirulent, do not invade the oral epithelium, do not elicit inflammatory responses in a healthy host, but induce regulatory immune responses that maintain tissue tolerance to the commensal fungi. The type, specificity and sensitivity of the protective immune response towards C. albicans is determined by the outcome of the integrated interactions between the intracellular signalling pathways of specific combinations of activated pattern-recognition receptors (TLR2, TLR4, Dectin-1 and Dectin-2). IL-17-mediated protective immune response is essential for oral mucosal immunity to C. albicans infection.

Alveolar ridge preservation immediately after tooth extraction

Ridge preservation procedures immediately after tooth extraction, are commonly used with a view to minimising remodelling and shrinkage of the alveolar ridge, associated with socket healing. These procedures may sometimes be effective, but they cannot completely prevent reduction in dimension of the ridge. Certain biomater als used may actually hamper normal deposition of bone within the healing socket, reducing bone trabeculae that can integrate with the implant surface. However, in extraction sockets in alveolar ridges of low bone density, particles of implanted bone substitute incorporated in the healing bone, may enhance the mechanical support for the implant, provided by normal healed bone of low trabecular density alone. This paper reviews biological rationales and procedures for ridge preservation immediately after extraction and comments on their clinical use.

Inflammation in the context of oral cancer

The link between cancer and inflammation is specific transcription factors that once activated have the capacity to enhance expression of genes that are common to both the regulation and the production of mediators of inflammation, and also to the regulation of the survival and proliferation of cancer cells. Cellular pathways activated by chronic inflammation brought about by chronic infections, by immune-mediated diseases, or by dysregulated wound healing at sites of repetitive tissue injury, constitute risk factors for initial cell transformation and for cancer progression. In established cancers, the cancer cells induce development of an exaggerated inflammatory state in the stroma, which in turn promotes cancer growth, invasion and metastasis. Inflammatory cells of myeloid origin in the tumour-associated stroma, mediate suppression of immune responses against cancer cells, which suppression favours tumour growth. Oral submucous fibrosis, and to a lesser extent oral lichen planus are precancerous conditions in which immuno-inflammatory processes are implicated in their pathogenesis, and in their cancerous transformation, if it occurs. Although there is some evidence for an association between oral squamous cell carcinoma on the one hand and dento-gingival bacterial plaques and chronic periodontitis on the other hand, the role of inflammation as the sole cause of cancerous transformation in such cases is not proven. The purpose of this article is to elaborate on some of the more important relationships between oral cancer and inflammation, and to comment on the role of inflammation in the pathogenesis of oral squamous cell carcinoma.

Noma (cancrum oris) in the South African context

Noma (cancrum oris) is a destructive necrotising disease affecting orofacial tissues predominantly of malnourished young children. It is characterised by a rapid acute onset which usually starts in the mouth, spreads intra-orally destroying soft tissue and bone and progresses to perforate the facial skin, causing disfigurement. Polybacterial anaerobic infection is critical too, but is not alone sufficient for the initiation of noma. Cofactors, first and foremost malnutrition, but also systemic viral and bacterial infections are crucial to the development of noma. A patient with necrotising stomatitis or noma must be admitted to hospital for antibiotic treatment, fluid and electrolytes as well as nutritional supplementation and general supportive treatment. The epidemiology of noma in the South African population is unknown, and the clinicopathological features are poorly characterised. Although worldwide there is no evidence that HIV infection is a strong risk factor for noma, HIV infection may play a substantial role in the pathogenesis of noma in South Africa.

Alcohol and oral squamous cell carcinoma

Alcohol is a risk factor for oral squamous cell carcinoma. It enhances the permeability of the oral epithelium, acts as a solvent for tobacco carcinogens, induces basal-cell proliferation, and generates free radicals and acetaldehyde, which have the capacity to cause DNA damage. Alcohol-associated malnutrition and immune suppression may further promote carcinogenesis. However, acetaldehyde, the first metabolite of ethanol, is the critical agent by which prolonged and excessive consumption of alcoholic beverages increases the risk of oral squamous cell carcinoma. Alcohol also acts synergistically with the products of tobacco combustion in the pathogenesis of oral squamous cell carcinoma.

Noma (cancrum oris): a report of a case in a young AIDS patient with a review of the pathogenesis

Noma (cancrum oris) is a mutilating necrotising disease of the orofacial tissues. It affects predominantly debilitated malnourished children, in whom the necrotic process may cause severe damage to mid-facial structures. Its aetiopathogenesis is uncertain, but its course is fulminating, and without timely intervention the disease may be fatal. Antibiotic treatment during any stage of necrotising stomatitis and of its sequel noma can stop progression of the disease; therefore detection and treatment of early intraoral necrotising lesions whether necrotising gingivitis, necrotising periodontitis or necrotising stomatitis are critical in preventing noma. We present an extreme case of noma in a malnourished HIV-seropositive child. There was an acute necrotic process affecting both the maxilla and the mandible with denudation of bone, spontaneous exfoliation of teeth, necrotising fasciitis and myonecrosis which destroyed the lips and cheeks and extended to the infra-orbital margins. There was severe disfigurement and severe impairment of function. Noma is primarily an anaerobic bacterial infection with secondary ischaemia leading to osteonecrosis and mid-facial destruction.

HPV-associated oral warts

Human papillomavirus (HPV) is strictly epitheliotropic, infecting stratified squamous cutaneous and mucosal epithelial cells. Oral HPV infection may be subclinical or putatively associated with benign or malignant oral neoplasms. The benign HPV-associated oral lesions, focal epithelial hyperplasia (Heck disease), oral squamous cell papilloma, oral verruca vulgaris (common wart) and oral condyloma acuminatum, are collectively referred to as oral warts. Oral warts are usually asymptomatic, may be persistent or uncommonly, may regress spontaneously. HPV-associated oral warts have a prevalence of 0.5% in the general population, occur in up to 5% of HIV-seropositive subjects, and in up to 23% of HIV-seropositive subjects on highly active antiretroviral therapy. This paper is a clinico-pathological review of HPV-associated oral warts.

Bisphosphonate-related osteonecrosis of the jaw

Bisphosphonates are agents commonly used in the treatment of osteoporosis, and in the management of metastatic bone disease, and of hypercalcaemia of malignancy. Any oral surgical procedure or traumatic event exposing bone to bacterial infection may precipitate osteonecrosis of the jaw in subjects who have been treated with bisphosphonates which suppress bone turnover and inhibit the angiogenesis associated with healing. New guidelines for the treatment of bisphosphonate-related osteonecrosis of the jaw are emerging, but hitherto treatment has been empirically conservative.

Primary Oral Tuberculosis as an Indicator of HIV Infection

We present a case of primary oral tuberculosis that led to the diagnosis of HIV infection. Our patient had clinically nonspecific ulcers on the labial mucosa and on the ventral surface of the tongue which were diagnosed as being tuberculous only on histological examination. This raised the suspicion of HIV infection that was subsequently confirmed by blood tests. The oral lesions resolved after 4 weeks of antituberculosis treatment. Some aspects of the pathogenesis of HIV-tuberculosis coinfection are discussed.

Oral cancer-associated paraneoplastic syndromes

Paraneoplastic syndromes are cancer-associated endocrinological, haematological, dermatological or neurological disorders, which are directly related neither to the physical effects of the tumour mass, nor to invasion by the primary tumour, nor to metastasis of the tumour; nor are they associated either with the side-effects of anticancer treatment or with any of the complications of cancer. These syndromes are brought about by the ectopic production of biological mediators by the malignant tumour cells, or by immunological responses to the malignancy. Certain cancers are typically associated with specific paraneoplastic disorders. Though uncommonly, oral carcinomata have reportedly been associated with paraneoplastic pemphigus, humoral hypercalcaemia of malignancy, syndrome of inappropriate antidiuretic hormone, and paraneoplastic leukocytosis syndrome.

Chemotherapy- and radiotherapy-induced oral mucositis: pathobiology, epidemiology and management

Oral mucositis is a debilitating complication of anticancer treatment, characterised by erythematous, atrophic, erosive or ulcerative lesions. Oral mucositis is almost always painful, affects eating, sleeping, and speech and affects the physiological and social well-being of the patient. The pathophysiology of the condition is not well understood. Guidelines to the treatment of oral mucositis are often contradictory so that there is no evidence based standard treatment protocol. Therefore the treatment is empiric. This paper offers a brief review of current knowledge of the pathophysiology and treatment of oral mucositis.

HPV modulation of host immune responses

Host immune responses to HPV are generally low-level because the virus, being confined to basal epithelial cells is shielded from the circulating immune cells during initial stages of infection. In this location there is only a limited expression of viral proteins. Other factors contributing to the low level of host immunity are that HPV infection is non-lytic (does not cause death of the infected cell); that a functionally active immune response is generated only at later stages of HPV infection, in post-mitotic suprabasal keratinocytes where all viral genes are expressed; and that only in suprabasal keratinocytes has the HPV DNA been sufficiently amplified to be detected by the host immune-surveillance cells. In addition to the natural low-level immune responses towards HPV, HPV also employs several mechanisms to down-regulate innate and cell-mediated immunity, thus facilitating host immune evasion and persistent infection. The environment, lifestyle, the genetic make-up of the host, and the viral genomic characteristics can also influence the persistence of HPV infection, and consequential diseases. Persistent infection with high-risk HPV is associated with increased risk of developing HPV-mediated premalignancy and malignancy. It is not clear if the natural humoral immune response as opposed to vaccination is effective in eliminating primary HPV infection or in preventing progression of infection; but after initial infection, the host develops HPV-specific T cell immune responses that appear to be capable of clearing established infection, of protecting against progression of early HPV-associated intraepithelial neoplastic lesions to squamous cell carcinoma, and of preventing reinfection.

Xeroderma pigmentosum: a case report and review of the literature

Inherited molecular defects in nucleotide excision repair genes cause the autosomal recessive condition xeroderma pigmentosum. Xeroderma pigmentosum is characterized by photo-hypersensitivity of sun-exposed tissues, and by a several thousand-fold increase in the risk of developing malignant neoplasms of the skin and of the eyes. Mutations in xeroderma pigmentosum genes that regulate nucleotide excision repair, not only predispose persons with xeroderma pigmentosum to multiple malignancies, but also promote premature cutaneous and ocular ageing, and in some cases promote progressive neurodegenerative changes. This paper describes a case of xeroderma pigmentosum with advanced cutaneous squamous cell carcinoma, actinic cheilitis and ocular lesions in a 19-year-old black woman. The extensive ultraviolet radiation-induced skin and eye damage are evidence of neglect of sun-protection and lack of appropriate medical care from childhood.

Focal epithelial hyperplasia (Heck disease) related to highly active antiretroviral therapy in an HIV-seropositive child. A report of a case, and a review of the literature

Focal epithelial hyperplasia is increasingly frequently observed in rural South African communities. HIV-seropositive subjects have a higher prevalence of oral human papillomavirus (HPV) infections than immunocompetent subjects; and paradoxically, the introduction of highly active antiretroviral therapy for treatment of HIV-seropositive subjects is associated with increased frequency of focal epithelial hyperplasia. We describe a case of focal epithelial hyperplasia in an HIV-seropositive child receiving highly active antiretroviral therapy, who was successfully treated by using diode laser ablation.

The pathobiology and mechanisms of infection of HPV

There are more than 120 types of low-risk and high-risk human papillomaviruses, all of which are epitheliotropic. HPV infection may be latent, or active in a subclinical form or a symptomatic form, the latter manifesting as benign or malignant neoplasms. In basal cells with non-productive HPV infection some early HPV proteins are expressed independently of cell maturation: the productive cycle of HPV replication depends upon specific cellular factors of the maturation of the infected keratinocytes. In HPV-mediated oncogenesis, the combined pathobiological effects of E6 and E7 oncoproteins of high-risk HPV culminate in cellular genomic instability and transformation of persistently infected cells, that progress to the development of a malignant phenotype. In this article we provide insights into the stages of HPV infection, and into the viral genomic organization and replicative cycle.

Facial lymphoedema as an indicator of terminal disease in oral HIV-associated Kaposi sarcoma

Rapidly progressive facial lymphoedema developing concurrently with, or immediately after rapid enlargment of oral Kaposi sarcoma (KS) in HIV-seropositive highly active antiretroviral treatment (HAART)-naïve subjects, foretokens death. We present here an unusual case of HIV-KS in an 11-year-old HIV-seropositive HAART-naïve boy. Our patient's KS disease had had a fulminant course characterised by rapidly progressing oral HIV-KS, resorption of the mandibular alveolar bone process beneath some of the HIV-KS lesions, and rapidly progressive facial lymphoedema. He died 3 weeks after the onset of facial lymphoedema.

HIV-associated Kaposi sarcoma in African children

HIV-associated Kaposi sarcoma (HIV-KS) is common in African countries where HIV infection is pandemic and anti-retroviral medication is not readily available. Human herpesvirus-8 (HHV-8), which is the essential, but not the sole aetiological factor in KS, is endemic in sub-Saharan Africa and is substantially more prevalent in HIV-seropositive than in HIV-seronegative subjects. In children in sub-Saharan Africa, KS, whether it be HIV-KS or African endemic KS is much more prevalent than any other epidemiological forms of KS. In addition, in sub-Saharan children oral KS is common, and the life-expectancy of HIV-seropositive children with KS is short. Since generalized systemic KS is frequently associated with oral HIV-KS, it is advisable to introduce systemic cytotoxic chemotherapy early in the course of oral HIV-KS. Although the introduction of highly active antiretroviral therapy (HAART) brought about a decline in the incidence of HIV-KS worldwide, HIV-KS remains a significant problem in sub-Saharan Africa where the prevalence of HHV-8 infection is high and access to HAART is limited.

Tuberculosis part 4: Control of Mycobacterium tuberculosis transmission in dental care facilities

The risk of transmission of Mycobacterium tuberculosis (Mtb) in oral healthcare facilities is probably low, but the consequences if it occurs, are grave. The greatest risk of exposure to Mtb transmission is associated with treating dental patients from communities with a high prevalence of tuberculosis (TB) and HIV disease because these patients may have active TB but be unaware of their status. The risk of Mtb transmission in the dental surgery is heightened by dental treatment with ultrasonic and air operated high speed instruments that generate aerosols. This article offers recommendations for the necessary components of an effective Mtb infection control programme.

Tuberculosis part 3: HIV-tuberculosis co-infection

Tuberculosis is the most common opportunistic infection in HIV-seropositive persons. Tuberculosis may occur at any stage of HIV disease but the prevalence of TB increases with the progressive diminution of CD4+ T cell numbers. There is a synergistic relationship between tuberculosis and HIV infection as each accelerates the progression of the other.

Osteosarcoma of the jaw. A brief review and a case report

Osteosarcoma of the jaws accounts for 6-13% of all osteosarcomata. If not diagnosed early, it spreads extensively through the jaw and contiguous soft tissues into the nasal cavity, the maxillary sinus, the orbit and the infratemporal fossa, and may invade the oral soft tissues. A clinical finding of tooth displacement and tooth mobility associated with radiolucency/radiopacity should alert the practitioner to the possibility of osteosarcoma or some other malignancy.

Insights into immunopathogenic mechanisms of HIV infection: high levels of immune activation and HIV fitness

Progressive diminution in the number, and decline in the function of CD4+ T cells are the hallmarks of HIV infection. The pathogenic mechanisms responsible for the progression of the disease to acquired immunodeficiency syndrome (AIDS) are not well understood, but it appears that HIV-induced immune activation and increase in HIV viral fitness play an essential role in the pathogenesis of HIV infection. In this paper HIV fitness in relation to the chronic immune activation in HIV infection will be discussed.

Plasma cell gingivitis: does it exist? Report of a case and review of the literature

Plasma cell gingivitis is an uncommon inflammatory condition of uncertain aetiology. It is characterized clinically by enlarged erythemathous gingivae, a velvety texture and histopathologically by a dense plasmacytic infiltrate in the lamina propria. We present a case of a 19-year-old female who had what appeared to be plasma cell gingivitis. The clinical and histopathological differential diagnosis of plasma cell gingivitis is discussed and an argument is presented raising certain doubts whether plasma cell gingivitis is a distinct clinicopathological entity or not.

Congenital epulis. A case report

Congenital epulis (CE) is an uncommon granular cell lesion of unknown pathogenesis and uncertain histogenesis that presents at birth. It is a benign hamartoma that may interfere with feeding and respiration. The treatment of CE is by simple excision. In the 136 years since CE was first described, more than 200 cases of CE have been reported in the literature.

Idiopathic gingival fibromatosis: a review of the literature and a case report

Gingival fibromatosis is characterized by localized or generalized fibrous enlargement of the gingivae, mainly around permanent teeth. Gingival fibromatosis affects only the masticatory mucosa and does not extend beyond the muco-gingival junction. This article describes an unusual case of idiopathic gingival fibromatosis with delayed eruption of permanent teeth in an 8 year-old boy. The pathogenic mechanisms that bring about gingival fibromatosis are discussed.

Localized aggressive periodontitis associated with unusual gingival enlargement posing a diagnostic dilemma: a case report

This is a case report of localized aggressive periodontitis associated with unusual gingival enlargement. There was difficulty both clinically and histologically in deciding whether the gingival enlargement was a pyogenic granuloma or a Kaposi sarcoma. The diagnosis of Kaposi sarcoma was eventually ruled out by the failure of immunohistopathological examination to demonstrate the presence of HHV-8 DNA markers, and by the clinical response of the lesions to antimicrobial agents. Once a definitive diagnosis was made, the patient was treated conventionally.

Enamel dysplasia with hamartomatous atypical follicular hyperplasia (EDHFH) syndrome: suggested pathogenic mechanisms

The syndrome of enamel dysplasia with hamartomatous atypical follicular hyperplasia (EDHFH) is an unusual syndrome and is unique to black South Africans. Major criteria for the syndrome are enamel dysplasia with generalized amelogenesis imperfecta-like features and atypical hyperplastic dental follicles with microscopic features of central odontogenic fibroma WHO-type (follicle analogue) attached to the crowns of multiple impacted teeth. Minor features of some cases are anterior open-bite malocclusion, supernumerary teeth, pulpal calcification, aberrant roots with hypercementosis, and hypodontia. The pathogenic mechanisms that lead to the development of EDHFH are unknown. We speculate that faulty synthesis of enamel matrix proteins may interfere with enamel formation and play a role in the generalized enamel hypoplasia described in this syndrome. Alterations in inductive signalling by the odontogenic epithelium mediated by enamel matrix proteins may explain the development of the follicle analogues, the root hypercementosis and the presence of dysplastic cementum deposition juxtaposed to odontogenic epithelium in the gingival overgrowth. Thus, alterations in the function of enamel matrix protein function, may be the common denominator responsible for the development of the EDHFH phenotype.

Alveolar bone necrosis and spontaneous tooth exfoliation in an HIV-seropositive subject with herpes zoster

Herpes zoster in the distribution of the maxillary and mandibular divisions of the trigeminal nerve is characterized by painful vesicular eruptions of the skin and oral mucosa in the distribution of the affected nerves. Oral complications may occur, including post-herpetic neuralgia, devitalization of teeth, abnormal development of permanent teeth, root resorption and periapical lesions. In cases where necrosis of the alveolar bony process occur it may be preceded or accompanied by spontaneous exfoliation of teeth. This usually follows the resolution of the acute phase of HZ and is more prevalent in HIV-seropositive than in HIV-seronegative subjects. A case of HZ of the trigeminal nerve in an HIV-seropositive subject, with complications of necrosis of alveolar bony process, external root resorption and tooth exfoliation is presented and the literature of HIV-associated HZ is reviewed.

Enamel dysplasia with hamartomatous atypical follicular hyperplasia: review of the literature and report of a case

This article documents an additional case of a rare syndrome, reported only in black persons in South Africa. It is characterised by hamartomatous atypical follicular hyperplasia with central odontogenic fibroma (WHO-type)-like features attached to multiple impacted teeth, and with generalized enamel dysplasia showing features of hypoplastic amelogenesis imperfecta. Other features associated with the syndrome, but not present in all reported cases, include open-bite malocclusion, gingival overgrowth, hypodontia, pulpal calcifications and aberrant root formation of the unerupted teeth. Our present case shows the additional feature of impacted supernumerary teeth. As we cannot find any reports in the literature of the occurrence of amelogenesis imperfecta-like enamel dysplasia associated with hamartomatous follicular hyperplasia showing the features of WHO-type central odontogenic fibroma, with or without the additional features mentioned above, we propose to name this syndrome Enamel Dysplasia with Hamartomatous atypical Follicular Hyperplasia (EDHFH) syndrome.

Primary oral melanoma associated with HIV infection

POM, when it occurs, is most common in the palate and the maxillary gingiva. It has a poor prognosis. Surgical excision is the treatment of choice while radiotherapy and chemotherapy are adjunctive. This report documents an unusual case of POM and reviews field cancerization in POM.

The prognostic significance of facial lymphoedema in HIV-seropositive subjects with Kaposi sarcoma

Background

Kaposi Sarcoma (KS) is a multifocal angioproliferative neoplasm characterized by inflammation, oedema, neoangiogenesis and spindle cell proliferation. The pathogenesis of human immunodeficiency virus (HIV)-associated KS (HIV-KS) is multifactorial. HHV-8 is an essential factor but not in itself sufficient to cause HIV-KS, the development of which is influenced by HIV, by increased production of cytokines and by growth factors. Whether HIV-KS is a true malignancy or a reactive hyperplastic inflammatory condition is debatable.

Results and Conclusion

Oedema of the face, legs and hands is a prominent feature of HIV-KS and is probably caused by lymphoedema related to the HIV-KS lesions. The cases of two HIV-seropositive subjects with KS-associated facial lymphoedema are reported. Extensive oral HIV-KS in association with facial oedema in the absence of anti-retroviral treatment appears to be an indication of a poor prognosis.

Aspects of immunopathogenic mechanisms of HIV infection

Human immunodeficiency virus (HIV) infection is characterized by progressive deterioration of the immune system nearly always resulting in death. Depletion in the numbers of CD4+ T cells is the hallmark of HIV infection and is central to the development of the clinical signs and symptoms that are characteristic of HIV disease. Other factors influencing the progression of HIV disease include the HIV viral load, the nature of the particular infecting HIV, and the level of competence of the immune effector cells.

Oral histoplasmosis as the initial indication of HIV infection: a case report

Histoplasmosis is an opportunistic infection. In HIV-seropositive subjects, histoplasmosis tends to have a progressive and disseminated course. Oral lesions occur frequently and multiple sites within the mouth can be affected. Diagnosis of histoplasmosis is made by microscopic identification and culture of the fungus in material taken from the affected site. We present a case of oral histoplasmosis in which the mouth was the primary site of the fungal disease and this was the initial indicator of HIV infection. There were lesions of the gingivae and there was destruction of the hard palate with extension into the right maxillary sinus and the right nasal cavity.