Elena Bardellini

Recruitment of dendritic cells in oral lichen planus

Using immunohistochemistry the presence of different dendritic cell (DC) subsets was analysed in 16 biopsies from patients with oral lichen planus (OLP). A significant increase of CD1a+/Langerin+ Langerhans cells, DC‐SIGN+ DC and CD123+/BDCA2+ plasmacytoid DCs (PDCs) was found in the epithelium and in the stroma of OLP biopsies compared to normal oral mucosa. A proportion of DCs were mature DC‐LAMP+ and expressed S100 or CD11c, typically found in the interdigitating DCs of nodal T‐cell areas. Double staining revealed that mature DCs co‐expressed CCR7, thus indicating the development of a nodal migratory phenotype upon maturation. Significant recruitment of PDCs producing IFN‐α was demonstrated by the expression of MxA within the lichenoid inflammatory infiltrate and close cell‐to‐cell contacts between PDCs and mature DCs were observed, with a significant correlation between the numbers of these two populations. Moreover, PDCs were also found to contain Granzyme‐B, an associated‐cytotoxic granule protein, inducing target cell apoptosis. Taken together, these results suggest that PDCs may promote maturation of DCs and amplify the cytotoxicity of lymphoid cells. Finally, the recruitment of different subtypes of DC, such as Langerhans cells, stromal DC‐SIGN+ DCs and PDCs, associated with a significant proportion of mature DCs, acquiring a CCR7+ ‘migratory’ phenotype, indicate that they may play a pivotal role in the development of the lichenoid inflammatory infiltrate that occurs typically in OLP. Copyright

NF‐κB expression in oral and cutaneous lichen planus

Lichen planus (LP) is a chronic inflammatory disorder involving cutaneous and mucosal surfaces, characterized by a T‐cell‐mediated immune response against epithelial cells, with persistent accumulation of T lymphocytes and epithelial cell damage. The mechanisms involved in this chronic inflammatory disease are largely unknown. A pivotal role in the pathogenesis of long‐lasting inflammatory processes is played by the activation of nuclear factor kappa B (NF‐κB), a primary transcription factor which upon translocation to the nucleus, binds to promoter regions of different genes encoding immune and pro‐inflammatory mediators. Using immunohistochemistry, the present study analysed the expression of NF‐κB in 25 cases of cutaneous LP (CLP) and 28 cases of oral LP (OLP) and correlated this with the recruitment of cytotoxic T‐cells (expressing Tia‐1 or perforin) in the inflammatory infiltrate. Nuclear NF‐κB was expressed on basal and suprabasal keratinocytes in all cases of LP, while normal epithelium was consistently negative; OLP contained significantly higher numbers of NF‐κB‐positive keratinocytes than CLP (means: 89.32 versus 22.6; p < 0.05). Furthermore, nuclear NF‐κB expression by epithelial cells correlated with the amount of cytotoxic cell infiltration (p < 0.02). These data suggest that increased NF‐κB activity may represent the basis of maintenance of the inflammatory response. The differences observed between NF‐κB expression on epithelial cells in OLP and CLP and their correlation with the degree of cytotoxic inflammatory infiltrate might explain the different clinical courses of the two variants of the disease, since OLP is typically more recalcitrant than CLP. As proposed for other chronic inflammatory disorders associated with increased NF‐κB activity, the involvement of NF‐κB in the pathogenesis of LP could be considered for selective therapeutic inhibitory targeting. Copyright

Cytotoxic Molecule Expression and Epithelial Cell Apoptosis in Oral and Cutaneous Lichen Planus

We evaluated the expression of T cell-restricted intracellular antigen (Tia-1), granzyme B, and perforin by lymphocytes and the degree of epithelial apoptosis in oral and cutaneous lichen planus (LP) in 51 untreated cases, including 27 oral LP (OLP) and 24 cutaneous LP (CLP) cases. The number of total dermal-positive lymphocytes in OLP and CLP was similar, indicating similar activity of the inflammatory process. Intraepithelial Tia-1-positive, perforin-positive, and granzyme B-positive lymphoid cells were more numerous in OLP than in CLP (P < .05). The epithelial cell apoptotic index (AI) was increased significantly in OLP (P < .05), particularly in erosive-atrophic variants. A linear correlation between AI and the mean +/- SEM number of intraepithelial and dermal perforin+ cells (6.85 +/- 2.44 and 27.48 +/- 10.19, respectively), per 10 high-power fields for OLP and for CLP (1.17 +/- 0.88 and 10.42 +/- 5.74, respectively), was found (intraepithelial, r = 0.50; dermal, r = 0.51; P < .01). These data suggest a pivotal role for perforin in triggering epithelial cell apoptosis. The differences of infiltrating cytotoxic cells and related AI observed in OLP and CLP are in keeping with the clinical behaviors that distinguish these LP variants.

Oral mucosal lesions in children from 0 to 12 years old: ten years' experience

OBJECTIVE The exact prevalence of oral lesions in childhood is not well known. We sought to define the prevalence of oral mucosal lesions in a large group of children. STUDY DESIGN A retrospective cross-sectional study was performed using clinical charts from January 1997 to December 2007. Data collected included age, gender, and pathologic diagnosis. RESULTS In total, 10,128 children (0-12 years old) were enrolled. Clinical diagnostic criteria proposed by the World Health Organization were followed. The frequency of children presenting oral mucosal lesions was 28.9%, and no differences related to gender were observed. The most frequent lesions recorded were oral candidiasis (28.4%), geographic tongue and other tongue lesions (18.5%), traumatic lesions (17.8%), recurrent aphthous ulcerations (14.8%), herpes simplex virus type 1 infections (9.3%), and erythema multiforme (0.9%). Children suffering from chronic diseases had a higher frequency of oral lesions compared with healthy children (chi-square: P < .01). CONCLUSION Mucosal alterations in children are relatively common, and several oral disorders are associated with underlying medical conditions.

Dentinogenesis imperfecta in children with osteogenesis imperfecta: a clinical and ultrastructural study

AIM The aim of this study was to assess the correlation between osteogenesis imperfecta (OI) and dentinogenesis imperfecta (DI) from both a clinical and histological point of view, particularly clarifying the structural and ultrastructural dentine changes. DESIGN Sixteen children (6-12 years aged) with diagnosis of OI were examined for dental alterations referable to DI. For each patient, the OI type (I, III, or IV) was recorded. Extracted or normally exfoliated primary teeth were subjected to a histological examination (to both optical microscopy and confocal laser-scanning microscopy). RESULTS A total of ten patients had abnormal discolourations referable to DI: four patients were affected by OI type I, three patients by OI type III, and three patients by OI type IV. The discolourations, yellow/brown or opalescent grey, could not be related to the different types of OI. Histological exam of primary teeth showed severe pathological change in the dentin, structured into four different layers. A collagen defect due to odontoblast dysfunction was theorized to be on the base of the histological changes. CONCLUSIONS There is no correlation between the type of OI and the type of discolouration. The underlying dentinal defect seems to be related to an odontoblast dysfunction.

Clinicopathological features and malignant transformation of oral lichen planus: A 12-years retrospective study

Abstract Objective. Oral lichen planus (OLP) is known to be associated with the risk of developing oral squamous cell carcinoma (OSCC). The objective of this study was to investigate the clinicopathological features of OLP and the prevalence of malignant transformation in this setting. Materials and methods. This retrospective study was carried out on 204 medical records of patients with histologically proven OLP who received long-term follow-up (range 6 months–12 years). Data were entered in an informatic database. The statistical analysis, when needed, was performed with the chi-squared test for significance (p < 0.05). Results. At the moment of the diagnosis, out of 204 patients (163 female and 41 male; mean age 54.5 years), 107 patients (52.45%) suffered from systemic chronic diseases, in particular 46 (22.5%) from hepatitis C. Clinically, the reticular form of OLP was the predominant one and most patients had multiple oral sites of involvement. Fourteen patients showed extra-oral lesions. A percentage of malignant transformation less than 1% was found. In fact, two patients (0.98%) underwent a malignant transformation at a site previously diagnosed as OLP. Conclusions. At present, OLP is accepted as being a potential malignant disorder, therefore lifelong follow-up is recommended.

Implications of gluten exposure period, CD clinical forms, and HLA typing in the association between celiac disease and dental enamel defects in children. A case–control study

BACKGROUND The association between coeliac disease (CD) and dental enamel defects (DED) is well known. AIM The aim of this study was to investigate the prevalence of DED in children with CD and to specifically find the association of DED and gluten exposure period, CD clinical forms, HLA class II haplotype. DESIGN This study was designed as a matched case-control study: 250 children were enrolled (125 coeliac children - 79 female and 46 male, 7.2 +/- 2.8 years and 125 healthy children). Data about age at CD diagnosis, CD clinical form, and HLA haplotype were recorded. RESULTS Dental enamel defects were detected in 58 coeliac subjects (46.4%) against seven (5.6%) controls (P < 0.005). We found an association between DED and gluten exposure period, as among CD subjects the mean age at CD diagnosis was significantly (P = 0.0004) higher in the group with DED (3.41 +/- 1.27) than without DED (1.26 +/- 0.7). DED resulted more frequent (100%) in atypical and silent CD forms than in the typical one (30.93%). The presence of HLA DR 52-53 and DQ7antigens significantly increased the risk of DED (P = 0.0017) in coeliac children. CONCLUSIONS Our results confirmed a possible correlation between HLA antigens and DED.

Epithelial expression of vanilloid and cannabinoid receptors: a potential role in burning mouth syndrome pathogenesis.

Burning mouth syndrome (BMS) is an intra-oral burning sensation for which presently no medical or dental causes have been found, and in which the oral mucosa appears normal. It remains an unknown disease for which there is still no long-term treatment. The aim of this study was to assess the epithelial alteration of transient receptor potential vanilloid channel type 1 (TRPV1) and cannabinoid receptors type 1 (CB1) and type 2 (CB2) in the human tongue. The study was performed on eight healthy controls and eight BMS patients. All patients underwent a 3-mm punch biopsy at the anterolateral aspect of the tongue close to the tip. TRPV1, CB1 and CB2 immuno-histochemistry was carried out showing an altered expression of all receptors. In BMS patients there was increased TRPV1, decreased CB1 and increased CB2 expression in tongue epithelial cells also associated with a change in their distribution. It would appear that these receptors are related to BMS. These data could be useful for future characterization of BMS epithelial markers and therapy.

Timetable for oral prevention in childhood—developing dentition and oral habits: a current opinion

As most of the etiologic factors of malocclusion are of genetic origin and thus cannot be prevented, environmental causative factors have become the focus for correction. Early interception of oral habits may be an important step in order to prevent occlusal disturbances in children. The identification of an abnormal habit and the assessment of its potential immediate and long-term effects on the dentition and potentially on the craniofacial complex should be made at an early stage. This paper focuses on the most common oral habits influencing dentofacial growth in childhood and management of these habits in the developing dentition.

Dental Anomalies in Permanent Teeth after Trauma in Primary Dentition

OBJECTIVE This retrospective study aims to evaluate the prevalence of dental anomalies in permanent teeth as a result of a trauma concerning the predecessor primary teeth. STUDY DESIGN A total of 241 records of children (118 males and 123 females, mean age 3.62 ± 1.40) affected by trauma on primary teeth were analyzed. All patients were recalled to evaluate the status of the permanent successor teeth by clinical and radiographic investigations. RESULTS Out of 241 patients, 106 patients (for a total of 179 traumatized primary teeth) presented at the recall. Dental anomalies on successor permanent teeth were detected in 21 patients (19.8%), for a total of 26 teeth (14.5%) and 28 anomalies. Anomalies of the eruptive process were the most observed disturbances (60.7%), followed by enamel hypoplasia (25%) and white spots (14.3%). A higher percentage of anomalies on permanent teeth was observed when trauma occurred at an age less than 36 months (38.5% of cases). Intrusive and extrusive luxation were related with the most cases of clinical disturbances in the successor permanent teeth. CONCLUSIONS The results of this study highlight the risk of dental anomalies after a trauma in primary dentition, especially in early-aged children and in case of intrusive luxation.