Michele Scivetti

Oral lichen planus: update on etiopathogenesis, diagnosis and treatment

Lichen planus is an inflammatory mucocutaneous disorder. Skin, oral and genital mucosal surfaces, scalp, and nails can be affected. Its development is chronic, with a possible malignant degeneration. Spontaneous remission is rare. Although the etiology of oral lichen planus is still unclear, there is evidence that it is a complex immunologic disease mediated by cytotoxic cells directed against basilar keratinocytes and resulting in vacuolar degeneration and lysis of basal cells. In long-standing, atrophic and erosive forms, the treatment is usually aimed at relieving pain and may include immunosuppressive agents, especially corticosteroid, topical cyclosporin, or tacrolimus, topical and systemic retinoids. However, the use of these drugs may be accompanied by several side effects. For this reason clinicians, currently, have focused their attention to new biological agents which provide selective immunological results with less side effects than generic immunosupressants.

Pathogenetic mechanisms in hereditary dysfunctions of complex I of the respiratory chain in neurological diseases.

This paper covers genetic and biochemical aspects of mitochondrial bioenergetics dysfunction in hereditary neurological disorders associated with complex I defects. Three types of hereditary complex I dysfunction are dealt with: (i) homozygous mutations in the nuclear genes NDUFS1 and NDUFS4 of complex I, associated with mitochondrial encephalopathy; (ii) a recessive hereditary epileptic neurological disorder associated with enhanced proteolytic degradation of complex I; (iii) homoplasmic mutations in the ND5 and ND6 mitochondrial genes of the complex, coexistent with mutation in the nuclear PINK1 gene in familial Parkinsonism. The genetic and biochemical data examined highlight different mechanisms by which mitochondrial bioenergetics is altered in these hereditary defects of complex I. This knowledge, besides clarifying molecular aspects of the pathogenesis of hereditary diseases, can also provide hints for understanding the involvement of complex I in sporadic neurological disorders and aging, as well as for developing therapeutical strategies.

The β-adrenoceptor agonist isoproterenol promotes the activity of respiratory chain complex I and lowers cellular reactive oxygen species in fibroblasts and heart myoblasts

A study is presented on the effect of the β-adrenoceptor agonist isoproterenol on mitochondrial oxygen metabolism in fibroblast and heart myoblast cultures. Isoproterenol treatment of serum-limited fibroblasts and proliferating myoblasts results in the promotion of mitochondrial complex I activity and decrease of the cellular level of reactive oxygen species. These effects of isoproterenol are associated with cAMP-dependent phosphorylation of complex I subunit(s). Addition of okadaic acid, inhibitor of protein phosphatase(s), reverses the decline of complex I activity in serum-limited fibroblast cultures and activates the complex in proliferating myoblast cultures. The effects of isoproterenol on complex I activity and reactive oxygen species balance can contribute to the therapeutic effect of the drug.

Analysis of Collagen Distribution in Human Crown Dentin by Confocal Laser Scanning Microscopy

The authors used confocal laser scanning microscope to analyze human crown dentin. Specimens from 10 teeth were divided in two groups, one of which was decalcified and stained with hematoxylin and eosin. In the second group an undecalcified section was analyzed. Both groups were scanned by confocal microscope to generate optically sectioned images. All of the analyzed samples presented an intense autofluorescent that was ascribed to collagens. The degree of autofluorescence intensity was variable and might be due to collagen expression. The results indicate that a confocal microscope may be of help in analyzing and defining the nature and extent of collagen fibrils in human dentin.

Oral lichenoid lesions in HIV-HCV-coinfected subjects during antiviral therapy: 2 cases and review of the literature.

Some dental materials and certain drugs may induce epithelial alterations, which clinically resemble oral lichen planus (OLP), on oral mucosa. But these alterations do not have all the clinical and/or the histological features of OLP; these lesions are known as oral lichenoid lesions (OLLs). Some researchers describe the onset and/or the worsening of OLL/OLP after the administration of anti-hepatitis C virus (HCV) therapy. In this article, we describe the development of symptomatic OLLs, as a consequence of anti-HCV therapy (interferon-alpha and ribavirine), in 2 human immunodeficiency virus-HCV-coinfected subjects. An immunological cause related to coinfection and administration of different medications could be responsible for the onset of OLLs. These new cases, together with the previous reports of a possible association between OLP and/or OLL and anti-HCV therapy, highlight the absolute need to monitor carefully the human immunodeficiency virus-HCV-coinfected subjects who are about to start the anti-HCV therapy and to define better the clinical and histopathological criteria to distinguish OLP from OLL.

Calcifying Odontogenic Cysts Associated with Odontomas: Confocal Laser Scanning Microscopy Analysis of 13 Cases

The so-called calcifying odontogenic cyst (COC) represents a heterogeneous group of lesions that exhibit a variety of clinico-pathologic features. It is an uncommon lesion and represents less than 2% of all odontogenic cysts and tumors. Recently, these lesions have been reclassified as calcifying cystic odontogenic tumors (CCOT), according to the new World Health Organization (WHO) classification. CCOT are frequently found in association with, or containing areas histologically identical to, various types of odontogenic tumors, such as complex/compound odontomas. This work analyzed clinical and histological data deriving from 13 patients affected by CCOT associated with odontomas. Moreover, a confocal laser scanning microscope (CLSM) analysis was undertaken to further a better understanding of the nature of this peculiar lesion.

Chondroma of the tongue

Chondroma is a remarkably rare lesion of the oral soft tissues. Most previously reported chondromas of this area have been associated with varying percentages of fibrous, adipose or bone tissues, and the occurrence of such neoplasms exclusively composed of chondromatous tissue is exceedingly rare. We report the clinicopathological features of a pure chondroma of the dorsum of the tongue, occurring in a 51‐year‐old woman and discuss the possible origin of the tumour.

Dens invaginatus: a qualitative-quantitative analysis. Case report of an upper second molar.

Dens invaginatus (D.I.) is a developmental anomaly caused by the infolding of the surface of a tooth crown before calcification has occurred. Its aetiology is controversial and remains unclear. It occurs in all dentitions with a prevalence that ranges from 0.25% to 7.74% and is mostly seen in the maxillary permanent incisors, particularly in the lateral incisors. Posterior teeth are infrequently involved. The purpose of this study was to investigate the morpho‐structure of a second upper molar dens invaginatus compared with a control tooth. Ground and decalcified sections were prepared and histo‐morphological evaluation of dental tissues was performed by using light microscopy, microradiography, and confocal laser scanning microscopy analysis (CLSM). The mechanical behaviour was tested by means of microhardness (HV) test. The results of our investigation showed structural anomalies of hard tissues, such as a difference in enamel prism diameter, in number and diameter of peripulpal dentinal tubules and in surface and diameter of cementocyte lacunae between D.I. and control tooth.

Oral lesions in HIV and HCV co‐infected individuals in HAART era

BACKGROUND During recent years, a new population of HIV and HCV co-infected subjects has emerged presenting particular oral problems. The aim of our study was to determine the prevalence of oral lesions in HIV+ subjects and HIV and HCV co-infected subjects, to assess whether co-infection is a risk factor for the presence of oral lesions. METHODS 200 HIV+ subjects were consecutively enrolled, divided into two groups: Group 1 (130 HIV+ subjects) and Group 2 (70 HIV-HCV co-infected subjects) and visited by two oral medicine specialists. Epidemiological, laboratory and clinical parameters were gathered to determine the possible risk factors for oral lesions. RESULTS 52 on 200 subjects (26%) presented oral lesions: in Group 1, 25 on 130 subjects (19.23%) presented oral lesions, whereas in Group 2, 27 on 70 subjects (38.57%) presented oral lesions. Multivariate analysis showed that the following variables are statistically associated with the presence of oral lesions: HIV-HCV co-infection (OR = 2.32; 95% CI = 1.01-5.33: P < 0.05) and the use of drugs for the treatment of systemic diseases not associated with HIV (OR = 4.34; 95% CI = 1.78-5.33: P = 0.005). CONCLUSIONS It is possible to assess, on the basis of our results, that co-infected patients are more prone than HIV mono-infected patients to develop oral lesions and thus should undergo strict oral medicine monitoring.

Síndrome de Rendu-Osler-Weber o Telangiectasia Hemorrágica Hereditaria (HHT): Descripción de dos casos y revisión de la literatura

El sindrome de Rendu-Osler-Weber, tambien conocido como Telangiectasia Hemorragica Hereditaria, es un desorden vascular cuya prevalencia se estima que afecta a uno de cada 5-8.000 individuos. Se trata de una alteracion vascular displasica multisistemica de caracter autosomico dominante, asociada a dos genes, HHT1 y HHT2, que determinan mutaciones en el gen endoglina (ENG), localizado en el cromosoma 9, y por mutaciones en el gen ALK1, localizado en el cromosoma 12. El 95% de los afectados presentan epitaxis recurrentes, con edad media de comienzo a los 12 anos e incremento progresivo del sangrado nasal en frecuencia y severidad. Generalmente se presenta asociado a malformaciones arteriovenosas pulmonares y/o multiples telangiectasias en sistema gastrointestinal, manos, cara, cavidad oral y afectacion de otras visceras. El diagnostico inicial de HHT continua basandose en la presencia de signos clinicos compatibles junto con la historia familiar. Para el diagnostico molecular es necesario secuenciar las regiones codificantes cormpletas de los genes ALK1 y ENG. El test genetico no es positivo en el 100% de los pacientes con diagnostico clinico de HHT, siendo posible no encontrar en un mismo grupo familiar la mutacion comun. Se revisa la literatura y se presentan dos casos con manifestaciones orales en lengua y labio inferior, sin otras lesiones sistemicas asociadas, tratada en nuestro departamento por problemas odontologicos