Immunohistochemical expression of Tenascin in embryogenesis, tumorigenesis and inflammatory oral mucosa

Multiple coronally advanced flap with a selective use of connective tissue graft: A 3-year prospective clinical and histological study

BACKGROUND

The purpose of the present study was to prospectively evaluate the 3-year changes in the gingival dimensions following multiple coronally advanced flap (MCAF) with selective use of connective tissue graft (CTG). In addition, the secondary aim was to histologically identify the factors related to phenotype changes.

METHODS

Twenty patients treated with MCAF and site-specific application of a CTG were available for the 3-year follow-up. Outcome measures included complete root coverage (CRC), recession reduction, keratinized tissue width (KTW), marginal tissue thickness changes, and primary flap position. Biopsies were harvested at one of the sites treated with the adjunct of CTG. All sections were stained with hematoxylin and eosin, Masson trichrome, Verhoeff-van Gieson, tenascin, and alcian blue stain for semiquantitative evaluation.

RESULTS

At 3 years, CRC was detected in 86% of sites treated with MCAF alone and 81% of sites treated with MCAF + CTG. The 47% of sites treated with MCAF + CTG presented an apical shift of primary flap from its original position. Linear regression showed a significant association between KTW change and the initial KTW in MCAF-treated sites, while both initial KTW and position of primary flap were statistically significantly associated factors with KTW changes in the MCAF + CTG group. In all the biopsies examined, there is always a marked and clear separation between the connective tissue of the gingival flap and the palatal connective tissue of the graft.

CONCLUSIONS

The selective use of CTG is an effective treatment for multiple gingival recessions. Only a limited increase in KTW can be expected in a bilaminar technique if, during the healing phases, the connective tissue is maintained completely covered.

Functions of Matricellular Proteins in Dental Tissues and Their Emerging Roles in Orofacial Tissue Development, Maintenance, and Disease

Matricellular proteins (MCPs) are defined as extracellular matrix (ECM) associated proteins that are important regulators and integrators of microenvironmental signals, contributing to the dynamic nature of ECM signalling. There is a growing understanding of the role of matricellular proteins in cellular processes governing tissue development as well as in disease pathogenesis. In this review, the expression and functions of different MP family members (periostin, CCNs, TSPs, SIBLINGs and others) are presented, specifically in relation to craniofacial development and the maintenance of orofacial tissues, including bone, gingiva, oral mucosa, palate and the dental pulp. As will be discussed, each MP family member has been shown to have non-redundant roles in development, tissue homeostasis, wound healing, pathology and tumorigenesis of orofacial and dental tissues.

Roles of the matricellular protein Tenascin-C in T-lymphocyte trafficking and etiopathogenesis of Oral Lichen Planus

OBJECTIVE

This study was aimed at examining the role of Tenascin-C in T cell trafficking in Oral Lichen Planus (OLP).

DESIGN

For the in vivo immunohistochemical analyses, 115 OLP samples were collected from patients and immunostaining was performed. The intensity and distribution of TN-C expression were quantified and correlated with histological analyses of basement membrane integrity and presence of inflammatory infiltrate. For the in vitro study, TN-C and collagen were coated on culture plates and migration of T lymphocytes was assessed.

RESULTS

TN-C immunoexpression was increased in terms of both distribution and intensity along the basement membrane zone. These changes were significantly associated with basement membrane duplication (distribution p < 0.002 and intensity p < 0.001) and bands of inflammation (distribution p < 0.002 and intensity p < 0.001) assessed by Chi-square test. T lymphocytes demonstrated significant migration towards TN-C as compared to collagen (n = 3, p < 0.05).

CONCLUSIONS

These findings indicate TN-C may have a key role in promoting T cell migration at the epithelial-mesenchymal junction in OLP. These observations suggest TN-C could be a good target for therapeutic intervention, either in itself or synergistically with anti-inflammatory directed strategies in this chronic disease management.

Immunoexpression of tenascin as a predictor of the malignancy potential of oral leukoplakia associated with a tobacco habit

Oral leukoplakia is a morphological alteration of tissue that is an early indicator for malignancy. Tenascin (TN) is a large hexameric extracellular matrix (ECM) protein with anti-adhesive properties that fosters cell migration during development, wound healing and tissue remodeling; it is present in small amounts in adult tissues. Overexpression of TN in a pathological condition may be either a cause or a consequence of the disease. We evaluated the efficacy of TN for early prediction of tobacco-associated oral cancers. We studied retrospectively 95 cases of oral leukoplakia, including mild, moderate and severe cases, using immunohistochemistry for TN. We evaluated the intensity, area and pattern of TN expression. Greater intensity and area of TN expression was observed in mild and severe dysplasia than in moderate dysplasia. Most cases showed a reticular pattern of expression, especially in mild and moderate dysplasia; a fibrillar pattern was more evident in severe dysplasia. We also observed homogeneous expression pattern in some cases. TN is a marker for dysplastic changes in epithelium and its expression may be helpful for predicting the malignancy potential of tobacco-associated oral leukoplakia.