Molecular pathogenesis of oral submucous fibrosis - a collagen metabolic disorder

Reconstructive management of the rare bilateral oral submucos fibrosis using nasolabial flap in comparison with free radial forearm flap--a randomised prospective trial

BACKGROUND

Oral sub mucous fibrosis is a rare chronic, progressive, pre malignant collagen disorder of oral mucosa in people of Asian descent characterized by trismus, blanching and stiffness of mucosa, burning sensation in mouth and hypomobility of soft palate and tongue with loss of gustatory sensation. Betel nut chewing is the most common etiological agent. Surgery remains the main stay in severe cases and aims at release of fibrotic bands and resurfacing the raw areas with different options. Reconstruction can be done by using nasolabial flap or radial free forearm flap. The purpose of this study was to compare the mouth opening after the reconstruction with either nasolabial flap or radial free forearm flap.METHODS This study was carried out on fifty (50) patients with oral sub mucous fibrosis. Twenty five (25) of these were reconstructed by nasolabial flap and twenty five (25) were reconstructed by radial free forearm flap. At different intervals of their post-operative visits, they were evaluated for the interincisal distance and the difference between the two groups was assessed.RESULTS Average increase in interincisal distance was greater in patients reconstructed with radial free forearm flap compared with patient reconstructed by nasolabial flap i.e. 18.96 mm and 15.16 mm respectively with 'P' value > 0.05.CONCLUSIONS Based on the results of this study, there was no significant difference in mouth opening after reconstruction with radial forearm free flap compared to nasolabial flap [corrected].

Evaluation of the possible role of copper ions in drinking water in the pathogenesis of oral submucous fibrosis: a pilot study

We aimed to investigate the concentration of copper ions in drinking water and to assess whether copper has a role in the pathogenesis of oral submucous fibrosis (OSMF). We studied 50 patients with clinically and histologically diagnosed OSMF from the Yadgir district of Karnataka in India. Fifty healthy people matched for age and sex were used as controls. In both groups concentrations of copper ions in serum, saliva, and home drinking water were measured using atomic absorption spectroscopy and intelligent nephelometry technology. Serum ceruloplasmin concentrations were also estimated in both groups. The mean (SD) concentration of copper in the home drinking water of patients with OSMF was significantly higher (764.3 (445.9)μmol/L) than in the controls (305.7 (318.5)μmol/L) (p<0.001). Patients with OSMF also had a significantly higher copper concentrations in serum and saliva, and serum ceruloplasmin than controls (p<0.001). For the first time these data have shown a positive association between copper concentrations in home drinking water and OSMF. It raises the possibility that increased copper in drinking water contributes to the development of OSMF, and adds to that ingested when areca nut is chewed.

Prevalence and correlation of oral lesions among tobacco smokers, tobacco chewers, areca nut and alcohol users

INTRODUCTION

The incidence of oral premalignant and malignant lesions is on the rise due to an increased number of people taking in tobacco and alcohol related habits.

MATERIAL AND METHODS

1028 patients with tobacco, alcohol and areca nut habits attending our Department of Oral Medicine and Radiology formed the study sample. An interviewer based questionnaire was used to record the habit details. All the patients were then examined clinically for the presence of lesions. Chi square and Fisher exact tests were used to assess the statistical significance of the study parameters.

RESULTS

Males had a higher prevalence and comprised 87.9% of the sample. The commonest habit in this study sample was smoking (39.2%) followed by smokeless tobacco use (28.1%). Out of the 1028 patients with habits 40% had no clinically detectable changes in their mucosa. Of the mucosal changes leukoplakia (14%) was the commonest.

CONCLUSIONS

This study provided information about the habit trends in the patients visiting this institution. The study may serve as a useful tool in educating the patients about the deleterious effects of oral tobacco, alcohol and betel exposure.

Expression of transforming growth factor β and its correlation with lipodystrophy in oral submucous fibrosis: an immunohistochemical study

OBJECTIVE

In our routine review of Oral Submucous Fibrosis (OSMF) biopsies, we observed decreased adipose tissue even though most are from buccal mucosa. Pathogenesis of OSMF has demonstrated the role of Transforming Growth Factor β (TGF β), in causing fibrosis. This study aims to correlate the role of TGF β with loss of adipose tissue in OSMF.

STUDY DESIGN

From our archives, 84 OSMF cases (24 early and 60 advanced OSMF) were screened for adipose tissue. Immunoexpression of TGF β in these cases were investigated.

RESULTS

Adipose tissue was seen in 67% of early OSMF and in 13% of advanced cases. Early cases showed more intense TGF β staining of epithelium, fibroblast, macrophages and inflammatory cells than the advanced cases.

CONCLUSION

These findings suggest that TGF β plays a key role in causing lipodystrophy in OSMF and is secreted more during early course of the disease than in advanced stage.

Alteration of the inflammatory molecule network after irradiation of soft tissue

Inflammatory molecules (IMs) play an important role in ionizing radiation (IR)-induced soft tissue damage. The alteration of IMs as a function of time was studied with a protein array containing 62 IMs in mouse cutaneous soft tissues exposed to 30 Gy. The results showed that: (1) 2 days after irradiation, the levels of TGF-β1, MIP-1γ, IL-1α, and sTNF RI increased, while IGFBP-3, CXCL16, and IL-1β decreased in IR skin as compared to control skin; (2) 21 days after IR, TGF-β1, and MIP-1 γ, IL-1α remained high, while CXCL16 and IL-1β remained low; (3) 3 months after IR, the cytokine pattern exhibited reversals. The levels of MIP-1γ decreased, while VCAM-1, IGFBP-3, and TGF-β1 production increased. The data indicated that: (a) IMs change as a function of time after soft tissue irradiation; (b) changing IM levels may reflect the altered balance of the cytokine network, leading to imbalance or homeostasis; and (c) an antibody-based protein array can be used to assess multiple IMs simultaneously, making it useful for bulk screening for changes in tissue cytokine levels.

Efficacy of salvianolic acid B combined with triamcinolone acetonide in the treatment of oral submucous fibrosis

OBJECTIVE

The aim of this study was to investigate the effectiveness of triamcinolone acetonide (TA) and salvianolic acid B (SA-B) intralesional combined injection in the treatment of oral submucous fibrosis (OSF).

MATERIAL AND METHODS

A randomized clinical trial was performed. TA, SA-B, and TA combined with SA-B were consecutively applied intralesionally weekly for 20 weeks. Mouth opening and burning sensation improvement as determined by a 100-mm visual analog scale were evaluated at weeks 10, 20, and 44.

RESULTS

Forty-two subjects fulfilled the study without obvious adverse reactions. The net gain in mouth opening was 2.00 ± 1.21 mm in the TA group, 3.48 ± 2.23 mm in the SA-B group, and 5.50 ± 1.80 mm in the TA + SA-B group at week 44. The burning sensation improved by 3.05 ± 0.76 in the TA group, 4.96 ± 0.97 in the SA-B group, and 6.11 ± 0.93 in the TA + SA-B group by the end of the study.

CONCLUSIONS

TA + SA-B intralesional injections improved mouth open and burning sensation in these OSF patients.

Activation of TGF-β pathway by areca nut constituents: a possible cause of oral submucous fibrosis

Oral submucous fibrosis (OSF) is a chronic inflammatory disease characterized by the accumulation of excess collagen, and areca nut chewing has been proposed as an important etiological factor for disease manifestation. Activation of transforming growth factor-β signaling has been postulated as the main causative event for increased collagen production in OSF. Oral epithelium plays important roles in OSF, and arecoline has been shown to induce TGF-β in epithelial cells. In an attempt to understand the role of areca nut constituents in the manifestation of OSF, we studied the global gene expression profile in epithelial cells (HaCaT) following treatment with areca nut water extract or TGF-β. Interestingly, 64% of the differentially regulated genes by areca nut water extract matches with the TGF-β induced gene expression profile. Out of these, expression of 57% of genes was compromised in the presence of ALK5 (TβRI) inhibitor and 7% were independently induced by areca nut, highlighting the importance of TGF-β in areca nut actions. Areca nut water extract treatment induced p-SMAD2 and TGF-β downstream targets in HaCaT cells but not in human gingival fibroblast cells (hGF), suggesting epithelial cells could be the source of TGF-β in promoting OSF. Water extract of areca nut consists of polyphenols and alkaloids. Both polyphenol and alkaloid fractions of areca nut were able to induce TGF-β signaling and its downstream targets. Also, SMAD-2 was phosphorylated following treatment of HaCaT cells by Catechin, Tannin and alkaloids namely Arecoline, Arecaidine and Guvacine. Moreover, both polyphenols and alkaloids induced TGF-β2 and THBS1 (activator of latent TGF-β) in HaCaT cells suggesting areca nut mediated activation of p-SMAD2 involves up-regulation and activation of TGF-β. These data suggest a major causative role for TGF-β that is induced by areca nut in OSF progression.

Oral submucous fibrosis: an overview of the aetiology, pathogenesis, classification, and principles of management

Oral submucous fibrosis (OSMF) is a complex, debilitating, and precancerous condition. Formerly confined to the Indian subcontinent, it is now often seen in the Asian populations of the United Kingdom, USA, and other developed countries, and is therefore a serious problem for global health. The well-known causative agent of the disease, areca-nut is now recognised as a group one carcinogen. We review and discuss all components of OSMF, including the terminology, presentation, aetiology, and pathogenesis, and provide a brief overview of its management.

Autofluorescence spectroscopy of betel quid chewers and oral submucous fibrosis: A pilot study

Context:

Oral lesions related to the use of commercially available tobacco (gutkha) is going to pose a major challenge for health care providers in India. Therefore, techniques that are useful for mass screening of the public for early identification of pre-cancerous lesions and conditions are necessary to overcome this challenge.

Aims:

To identify the differences in autofluorescence spectra of normal oral mucosa, mucosa of betel quid chewers, and mucosa of oral sub mucous fibrosis.

Materials and Methods:

Group I consist of 15 individuals with clinical diagnosis of oral submucous fibrosis, Group II consists of 18 individuals without oral submucous fibrosis, having the habit of betel quid (gutkha) chewing and Group III consists of 18 normal individuals without the habit of betel quid chewing. Both males and females were included in the study with their age ranging from 18 to 53 years. In vivo fluorescence spectra were obtained using an optical fibre probe attached to Fluoromax-2 spectrofluorometer in the Department of Medical Physics, Anna University, Chennai, India.

Statistical Analysis Used:

Fisher's Chi square test was used for statistical analysis. Probability value (P value) was also obtained to discriminate the statistical differences between the three groups.

Results:

The averaged emission and excitation spectra of oral submucous fibrosis was significantly less compared to normal mucosa and betel quid chewers. The statistical findings showed significant differences (P<0.001) between oral submucous fibrosis and the other two groups.

Conclusions:

Fluorescence spectroscopy can be used effectively for diagnosing the individuals affected by OSMF. However, this technique was unable to discriminate the betel chewers mucosa from normal individuals.

Vasodilator isoxsuprine alleviates symptoms of oral submucous fibrosis

OBJECTIVES

The aim of the study was to compare the effectiveness of vasodilator isoxsuprine to dexamethasone with hyaluronidase injections and physiotherapy in the treatment of oral submucous fibrosis.

MATERIALS AND METHODS

Forty patients with oral submucous fibrosis were randomly assigned into three groups. Group A patients (n = 15) received 10 mg isoxsuprine tablets four times per day, group B (n = 15) biweekly dexamethasone with hyaluronidase intralesional injections, and group C (n = 10) placebo tablets. In addition, all patients were instructed physiotherapy exercises. The treatment time was 6 weeks and patients were followed-up for 4 months thereafter. The effect of the treatment was evaluated by measurements of inter-incisal distance and oral burning sensation and evaluation of histological findings of the diseased mucosa.

RESULTS

Mouth opening increased and burning sensation decreased significantly in all groups, but the effects were significantly greater in groups receiving either oral isoxsuprine or dexamethasone with hyaluronidase injections in addition to physiotherapy. The decrease in burning sensation occurred more rapidly in patients receiving intralesional dexamethasone with hyaluronidase. Histological improvement was not observed in any of the groups.

CONCLUSIONS

Oral isoxsuprine as well as dexamethasone with hyaluronidase injections combined to physiotherapy alleviate symptoms of oral submucous fibrosis significantly more efficiently than physiotherapy alone.

CLINICAL RELEVANCE

Oral isoxsuprine can be considered as a new candidate drug for the treatment of oral submucous fibrosis. Physiotherapy exercises provide relief of symptoms and should be instructed to all patients.

Antifibrotic effect of curcumin in TGF-β 1-induced myofibroblasts from human oral mucosa

BACKGROUND

Myofibroblasts play an important role in the development of oral submucous fibrosis (OSF). In the current study, we investigate the effect of curcumin on growth and apoptosis of myofibroblasts derived from human oral mucosa.

METHODS

Myofibroblasts were generated by incubating fibroblasts, obtained from human oral mucosa, with transforming growth factor-β 1 (TGF-β 1). MTT, PI staining, and FACS assays were used to investigate curcumin's effect on proliferation and cell cycle of fibroblasts and myofibroblasts. Annexin V/PI binding and FACS assays were used to examine apoptosis of myofibroblasts, Western blotting to determine the levels of Bcl-2 and Bax, and enzyme-linked immunosorbant assay was employed to examine the levels of collagen type I and III in the supernatants of myofibroblasts.

RESULTS

Curcumin inhibits proliferation of fibroblasts and myofibroblasts; it also disturbs the cell cycle, induces apoptosis and decreases the generation of collagen type I and III in myofibroblasts, which are more sensitive to its effects than fibroblasts. Curcumin induces apoptosis in myofibroblasts by down-regulating the Bcl-2/ Bax ratio.

CONCLUSION

Our results demonstrate the antifibrotic effect of curcumin in vitro. It may therefore be a candidate for the treatment of OSF.

Cys-X-Cys ligand 9 might be an immunological factor in the pathogenesis of oral submucous fibrosis and its concomitant oral lichenoid lesion

OBJECTIVES

Oral submucous fibrosis (OSF) is a chronic oral precancerous disease primarily caused by betel quid chewing. Some OSF patients are concomitant with oral lichenoid lesion (OLL), a white-streak lesion with a higher risk for cancerization, in OSF mucosa. Immunological reaction has been considered as one of their common pathogenic mechanisms. Cys-X-Cys ligand 9 (CXCL9) is an important factor to recruit effector neutrophils and lymphocytes in immunological reactions. However, the expression levels of CXCL9 in OSF and OLL remain unclear.

MATERIALS AND METHODS

We investigated the expression levels of CXCL9 in 10 normal buccal mucosa (NBM) samples and 56 OSF concomitant with OLL patients, and evaluated the possible mechanism of CXCL9 on their pathogenesis.

RESULTS

Our results showed NBM demonstrated negative CXCL9 expression. OSF stained positive CXCL9 mainly in the cytoplasm of inflammatory cells and endothelial cells throughout the superficial layer of connective tissue, while its concomitant OLL showed much stronger CXCL9 in all mononuclear cells of subepithelial inflammatory infiltration (p = 0.0006). There was an upregulated trend of CXCL9 expression from NBM to OSF to OLL. However, no significant association between CXCL9 expression and clinicopathologic parameters of patients was found.

CONCLUSIONS

In conclusion, CXCL9 was found for the first time to contribute to the immunological pathogenesis for both OSF and its concomitant OLL, indicating a continuously enhanced intensity of immunoreactivity in their pathogenic process.

CLINICAL RELEVANCE

CXCL9 might be a useful tool to monitor the phase and disease severity of OSF and OLL, and a potential target for further clinical therapy for both lesions.

Estimation of serum beta carotene levels in patients with oral submucous fibrosis in India

Oral submucous fibrosis (OSMF) is a chronic, insidious and disabling condition affecting the oral cavity, being especially prevalent in India and South East Asia. However, considering its high prevalence and potential to undergo malignant transformation, OSMF has not been widely investigated with respect to levels of antioxidants, especially beta carotene. In the present study, an attempt was made to analyze serum levels of beta carotene in 45 patients with oral submucous fibrosis and 45 age- and sex-matched controls. The serum beta carotene level was estimated using the Bradley and Hornbeck method. The serum beta carotene level was significantly lower in the patients with oral submucous fibrosis than in the controls. When the values were compared between different disease stages, the maximum reduction of beta carotene was evident for Grade III OSMF, as compared with Grade I and II. From the present results, it is evident that beta carotene plays an important role in the pathogenesis of OSMF, and that its level decreases with disease progression. OSMF patients should be treated with a diet rich in beta carotene to reduce disease severity and progression towards malignancy.

EGCG blocks TGFβ1-induced CCN2 by suppressing JNK and p38 in buccal fibroblasts

OBJECTIVES

Transforming growth factor β (TGFβ) has been suggested as the main trigger for the increased collagen production and decreased matrix degradation pathways in oral submucous fibrosis (OSF). Connective tissue growth factor (CTGF/CCN2) and cyclooxygenase-2 (COX-2) were found to overexpress in OSF. The aim of this study was to investigate the molecular mechanism underlying the TGFβ-induced CCN2 expressions in human buccal mucosal fibroblasts (BMFs) to identify the potential targets for drug intervention or chemoprevention of OSF.

MATERIALS AND METHODS

TGFβ-induced CCN2 expression and its signaling pathways were assessed by Western blot analyses in BMFs.

RESULTS

TGFβ1 stimulated CCN2 synthesis in BMFs. Pretreatment with c-Jun NH(2)-terminal kinase (JNK) inhibitor SP600125, p38 mitogen-activated protein kinase (MAPK) inhibitor SB203580, and activin receptor-like kinase 5 (ALK5) inhibitor SB431542 significantly reduced TGFβ1-induced CCN2 synthesis. Epigallocatechin-3-gallate (EGCG) completely blocked TGFβ1-induced CCN2 synthesis by inhibiting the phosphorylation of JNK and p38 MAPK. Prostaglandin E(2) (PGE(2)) inhibited the TGFβ1-induced CCN2 synthesis in human fetal lung fibroblasts IMR90 but not in BMFs.

CONCLUSIONS

The TGFβ1-induced CCN2 synthesis in BMFs could be mediated by the ALK5, JNK, and p38 MAPK pathways. EGCG blocks TGFβ1-induced CCN2 by suppressing JNK and p38 in BMFs.

CLINICAL RELEVANCE

The exceptional signal transduction pathways of TGFβ1-induced CCN2 production in BMFs contribute to the resistance of PGE(2) downregulation of CCN2 expression; therefore, the CTGF/CCN2 levels are maintained in the OSF tissues in the presence of COX-2. EGCG may serve as a useful agent in controlling OSF.

NBI flexible laryngoscopy targeted tissue sampling in head and neck cancer patients with difficult airways

Direct suspension laryngoscopic biopsy of neoplasms in larynx, oropharynx, and hypopharynx was an arduous procedure in patients with a history of head and neck cancer and difficult airways. This preliminary study was aimed to report the efficacy and safety of a narrow band imaging-guided biopsy of this category by flexible laryngoscopy. This is a retrospective chart review study conducted in setting of tertiary referral centre. Nineteen consecutive head and neck cancer patients with difficulty in general anesthesia and rigid endoscopic approach due to trismus, craniofacial deformities, and/or limited neck extension after cancer therapy were referred for endoscopic biopsy of their suspicious lesions in larynx, hypopharynx, or parts of oropharynx. Following topical anesthesia, a flexible laryngoscope was introduced through the nose into the pharynx. Under narrow band imaging magnified view, the specified tumor foci were biopsied in an office-based setting. All of the lesions were reached and biopsied to obtain sufficient tissue samples. The procedure took <20 min in every case. Twelve of the 19 pathologic examinations disclosed the malignancies at the first biopsy, and another underwent a second biopsy to prove cancer recurrence. The other six patients with benign lesions received further follow-up for at least 6 months and showed no recurrence. There were no complications associated with the technique. This study introduced that flexible laryngoscopy with narrow band imaging has the advantages of nimbleness, precision, and minimal morbidity. This combined technique may be a safe and promising method for tissue sampling of suspicious recurrence in head and neck cancer patients with difficult airways.

Evaluation of PTEN immunoexpression in oral submucous fibrosis: role in pathogenesis and malignant transformation

Oral submucous fibrosis (OSMF) is a chronic debilitating disease and a premalignant condition of the oral cavity characterized by generalized submucosal fibrosis. Despite its precancerous nature, the molecular biology regarding its malignant potential has not been extensively studied. PTEN, a known tumor suppressor gene is mutated in a majority of human cancers and has also been implicated in several fibrotic disorders. The present study aims to evaluate the expression of PTEN in OSMF and oral squamous cell carcinoma (OSCC) and correlate it with the pathogenesis and malignant transformation of OSMF. 60 cases total of OSMF (30) and OSCC (30) were subjected to immunohistochemistry using PTEN antibody. Ten normal oral mucosa (NOM) specimens were also stained as controls. There was progressive loss of PTEN expression from normal mucosa to OSMF and OSCC (p ≤ 0.001). Significant differences were observed for PTEN expression between NOM and OSMF, OSMF and OSCC as well as NOM and OSCC. Though a progressive loss of PTEN was noticed between early OSMF and advanced OSMF, the variation did not reach statistical significance (p ≥ 0.001). Data suggest that there is a significant loss of PTEN expression in OSMF as compared to normal oral mucosa and that this trend increased from OSMF to OSCC. Thus, alteration of PTEN is likely an important molecular event in OSMF pathogenesis and oral carcinogenesis.

Correlation of trace elemental profiles in blood samples of Indian patients with leukoplakia and oral submucous fibrosis

In order to ascertain possible correlation between alterations in trace elemental profile and the progression or regression of two most common potentially malignant disorders affecting oral cavity, namely oral submucous fibrosis and leukoplakia, blood from 60 patients from each group of patients as well from 30 healthy individuals was analyzed for elemental profiling employing EDXRF technique. Out of the 16 detected elements (K, Si, Ca, V, Cr, Ni, Mn, Fe, Cu, Zn, Se, Br, Rb, Sr, Co, and Pb), Mn, Fe, Zn, Br, and Co showed remarkable alteration in their profile in both leukoplakia and oral submucous fibrosis patients with respect to the normal healthy individuals. While Zn, Br, and Fe reflected similar changes--showing gross depletion in both the diseased groups, Mn and Co depicted inverse pattern of alterations in their concentrations in the two types of precancerous disorders when compared to the control subjects.

Areca nut in pathogenesis of oral submucous fibrosis: revisited

BACKGROUND

Oral submucous fibrosis is a disease due to a chronic, insidious change in fibro-elasticity, characterized by burning sensation in the oral cavity, blanching, and stiffening of the oral mucosa and oropharynx leading to trismus and inability to open the mouth. The symptoms and signs depend on the progression of the lesions and number of affected sites. It is predominantly seen in Indians and other Asians. Once the disease has developed, there is neither regression nor any effective treatment. It is considered as a pre-malignant stage of oral cancer, and the reported risk of malignant transformation varies from 2.3-7.6%.

CONCLUSIONS

The common etiological factor considered for this unremitting disease is use of areca nut; however, the precise mechanism still remains elusive and controversial. A wide range of treatment consisting of drugs, surgical therapy, and physiotherapy have been attempted till date, with varying degrees of benefit, but none of them have proved to be a cure for this disease. This field remains open for clinical trials and research. This paper aims to give an overview on the role of areca nut in the pathogenesis and malignant potential of oral submucous fibrosis.

Oral submucous fibrosis: a clinicopathologic review of 205 cases in Indians

INTRODUCTION

Oral submucous fibrosis is a disease due to a chronic, insidious change in fibro-elasticity, characterized by burning sensation in the oral cavity, blanching, and stiffening of the oral mucosa and oro-pharynx leading to trismus and inability to open the mouth. The symptoms and signs depend on the progression of the lesions and number of affected sites. It is predominantly seen in Indians and other Asians. Once the disease has developed, there is neither regression nor any effective treatment. There are only few studies on the frequency and clinicopathological feature of oral submucous fibrosis in the Indian population in recent years.

MATERIAL AND METHODS

The present study evaluated 205 cases of oral submucous fibrosis for the age, sex, site of involvement, duration of disease at the time of diagnosis, associated habits and common presenting symptoms, presence of other mucosal lesions, malignant potential, and the histopathology.

RESULTS AND DISCUSSION

Oral submucous fibrosis was seen in younger age (20-30 years) than that reported in literature and showed a characteristic male preponderance. A strong association with smokeless tobacco use especially arecanut in the form of gutkha was established and was related to earlier development of oral submucous fibrosis (OSMF), i.e., within a year of the habit. A total of 11.6% of cases were associated with malignancy and occurred predominantly in males.

CONCLUSION

This article gives an insight into OSMF in this part of southern India and adds to its biologic profile.

Evaluation of myofibroblasts in oral submucous fibrosis: correlation with disease severity

BACKGROUND

Oral submucous fibrosis (OSMF) is a chronic debilitating disease and a premalignant condition of the oral cavity characterized by generalized submucosal fibrosis. Myofibroblasts are contractile cells expressing α-smooth muscle actin (α-SMA) and are considered primary producers of extracellular matrix after injury. Their accumulation has been established as a marker of progressive fibrosis in organs like lungs, liver, kidney and skin. This study aims to evaluate the presence of myofibroblasts in various histological stages of OSMF.

MATERIALS AND METHOD

Seventy cases of OSMF, which were further categorized histologically into early (35 cases) and advanced (35 cases), were subjected to immunohistochemistry using α-SMA antibody for detection of myofibroblasts. Fifteen normal oral mucosa specimens were also stained as controls.

RESULTS

The number of α-SMA-stained myofibroblasts in OSMF was significantly increased when compared to that of the normal controls (P<0.001). Additionally, a statistically significant increase in the myofibroblasts population between early and advanced stages was observed (P=0.000).

CONCLUSIONS

Our results corroborate the possibility that OSMF actually represents an abnormal healing process in response to chronic mechanical and chemical irritation because of areca nut chewing as demonstrated by the increased incidence of myofibroblasts in this disease. Furthermore, the progressive increase in myofibroblasts from early to advanced stages suggests their potential use as markers for evaluating the severity of OSMF.

Management of oral submucous fibrosis: an overview

Oral submucous fibrosis is a disease due to a chronic, insidious change in fibroelasticity, characterized by burning sensation in the oral cavity, blanching, and stiffening of the oral mucosa and oro-pharynx leading to trismus and inability to open the mouth. The symptoms and signs depend on the progression of the lesions and number of affected sites. It is predominantly seen in Indians and other Asians. Once, the disease has developed, there is neither regression nor any effective treatment. It is considered as a pre-malignant stage of oral cancer and reported risk of malignant transformation varies from 2.3-7.6%.The common etiological factor considered for this unremitting disease is use of areca nut; however, the precise pathogenesis still remains elusive and controversial. A wide range of treatment consisting of drug management, surgical therapy, and physiotherapy have been attempted till date; with varying degrees of benefit, but none of them have proved to be a cure for this disease. This field remains open for clinical trials and research. This paper aims to provide an overview on various management modalities available for oral submucous fibrosis.

Coming to America: betel nut and oral submucous fibrosis

BACKGROUND

Oral submucous fibrosis (OSF) is an insidious precancerous disease affecting the oral cavity, pharynx and upper digestive tract. Its etiology is linked directly to betel nut use, which is common to the Indian subcontinent. With the increase in immigration of people from the Indian subcontinent to the United States, many American dental professionals will encounter this disease in the near future. The author provides a general overview of OSF.

METHODS

The author provides a literature review of OSF, including its epidemiology, etiology, clinical presentation, histopathology and treatment modalities.

RESULTS

OSF is a precancerous oral disease linked definitively to the use of betel nut. It is endemic to people in the Indian subcontinent. Patients' primary complaint is progressive trismus. Treatment is based on disease severity.

CLINICAL IMPLICATIONS

OSF is a debilitating but preventable oral disease. Its incidence in the United States will increase as the South Asian immigrant population expands. Consequently, American dental professionals may encounter patients with this disease, and it is important that they are aware of it. In addition, for dental care professionals practicing in a South Asian American community, public health education is important to inform the population about the deleterious oral health effects of betel nut consumption.

In vivo native fluorescence spectroscopy and nicotinamide adinine dinucleotide/flavin adenine dinucleotide reduction and oxidation states of oral submucous fibrosis for chemopreventive drug monitoring

Native fluorescence spectroscopy has shown potential to characterize and diagnose oral malignancy. We aim at extending the native fluorescence spectroscopy technique to characterize normal and oral submucous fibrosis (OSF) patients under pre- and post-treated conditions, and verify whether this method could also be considered in the monitoring of therapeutic prognosis noninvasively. In this study, 28 normal subjects and 28 clinically proven cases of OSF in the age group of 20 to 40 years are diagnosed using native fluorescence spectroscopy. The OSF patients are given dexamethasone sodium phosphate and hyaluronidase twice a week for 6 weeks, and the therapeutic response is monitored using fluorescence spectroscopy. The fluorescence emission spectra of normal and OSF cases of both pre- and post-treated conditions are recorded in the wavelength region of 350 to 600 nm at an excitation wavelength of 330 nm. The statistical significance is verified using discriminant analysis. The oxidation-reduction ratio of the tissue is also calculated using the fluorescence emission intensities of flavin adenine dinucleotide and nicotinamide adinine dinucleotide at 530 and 440 nm, respectively, and they are compared with conventional physical clinical examinations. This study suggests that native fluorescence spectroscopy could also be extended to OSF diagnosis and therapeutic prognosis.

Correlation of histopathological diagnosis with habits and clinical findings in oral submucous fibrosis

Background

Oral submucous fibrosis is a common oral health problem in India. This study was conducted to correlate the histopathological diagnosis with habits and clinical findings in patients suffering from oral submucous fibrosis (OSF).

Methods

Patients suffering from oral submucous fibrosis from the Departments of Otorhinolayngology and Pathology, Moti Lal Nehru Medical College, Allahabad, India were studied from 2004–2008. Detailed information was gathered in a pretested proforma. Emphasis was given to the various addictions, clinical findings and histological examination was done.

Results

Two hundred and thirty nine patients were studied, yielding a male to female ratio of 6.8:1. Maximum patients were in the 21–30 years age group with a marked male predominance. Of these, 197 (82.4%) patients chewed areca nut/dohra, 14 (5.8%) were smokers and 2 (0.8%) patients were habituated to alcohol. 89(37.2%) patients reported difficulty in opening of the mouth (trismus). 51 (57.4%) patients were found to have stage II (2–3 cm) trismus while rest had stage I and III. The buccal mucosa was found to be the most commonly involved site. On the basis of histopathological examination, 52(21.7%) were classified as OSF grade I, 75(31.3%) patients as grade II and 112(46.8%) had grade III disease.

Conclusion

The widespread habit of chewing dohra/paan masala is a major risk factor of OSF, especially in the younger age group. In this study, an increase in histopathological grading was found with severity and duration of addiction habit. However no significant correlation was found between clinical staging and histopathological grading.

Lack of reliable evidence for oral submucous fibrosis treatments

DATA SOURCES

Searches were made for relevant studies using the Cochrane Oral Health Group Trials Register, Cochrane Central Register of Controlled Trials, Medline, Embase and IndMED (bibliographic database of Indian biomedical journals). There were no language restrictions.

STUDY SELECTION

Randomised controlled trials were to be selected if they compared surgery, systemic or topical medicines, or other interventions, to manage the symptoms of oral submucous fibrosis (OSF).

DATA EXTRACTION AND SYNTHESIS

Two authors independently assessed trial quality and extracted trial data. Disagreements were resolved by consultation with a third author. Attempts were made to contact study authors where necessary for clarification and for additional information. Because of limited poor quality data, only a descriptive summary of the results of the included trials was carried out.

RESULTS

Two trials, involving 87 participants, evaluated either lycopene in conjunction with intralesional injections of a steroid, and pentoxifylline in combination with mouth-stretching exercises and heat. There were no reports of toxicity to the interventions but some side-effects, which were mostly gastric irritation to pentoxifylline, were noted.

CONCLUSIONS

The lack of reliable evidence for the effectiveness of any specific interventions for the management of OSF is illustrated by the paucity, and poor methodological quality, of trials retrieved for this review.

Upregulation of HIF-1alpha in malignant transformation of oral submucous fibrosis

BACKGROUND

Oral submucous fibrosis (OSF) is a precancerous condition showing extensive fibrosis of the submucosa and affects most parts of the oral cavity, including pharynx and upper third of the oesophagus. The molecules involved in the biological pathways of the fibrotic process appeared to be either down- or upregulated at different stages of the disease. Despite the precancerous nature, malignant transformation of the epithelium in the background of fibrosis has not been studied in detail. HIF-1alpha is a known transcription factor that is induced by hypoxia.

AIMS

To test the hypothesis that hypoxia plays a role in malignant transformation and progression of OSF.

MATERIALS AND METHODS

We used both formalin-fixed and frozen samples of OSF and normal mucosa to investigate the relationship between HIF-1alpha and epithelial dysplasia using immunohistochemistry and RT-PCR.

CONCLUSIONS

Our data indicate that HIF-1alpha is upregulated at both protein and mRNA levels in OSF and the correlation with epithelial dysplasia is statistically significant (P < 0.001). We propose that HIF-1alpha may play a role in malignant transformation of OSF. Further, over-expression of HIF-1alpha may contribute to the progression of fibrosis. It may be possible to use HIF-1alpha as a marker for malignant transformation of OSF.

Treatment of oral submucous fibrosis by collagenase: effects on oral opening and eating function

OBJECTIVE

Patients with oral submucous fibrosis (OSF) suffer from the limitation of the oral opening. The aim of this study was to develop a simple and rapid method to improve the opening of the oral cavity and determine its effect on the incidence of developing oral carcinoma.

METHODS

We first induced an OSF-like lesion in rabbits which histopathologically resembles OSF in betel nut chewers and evaluated the effects of exogenous collagenase on these lesions. We then applied the collagenase treatment regimen to patients with OSF.

RESULTS

Endogenous collagenase activities in normal oral mucosa of patients exhibited 3- to 5-fold higher levels than that of OSF tissues. The collagenase treatment not only resulted in a significant improvement of oral opening, but patients also experienced a striking reduction in hypersensitivity to spices, sour, cold, and heat which helped restore eating function. Sub-mucosal fibrous proliferation, persistently good vascularization, and a mild increase in thickness of the sub-mucosal fibrous tissues were noticed 10 months after collagenase treatment. Within the 2-year follow-up period none of the treated patients developed an oral squamous cell carcinoma.

CONCLUSION

A reduced content of functional collagenase observed in OSF mucosa of patients might be one mechanism responsible for collagen accumulation. Intervention of OSF by collagenase treatment at the early stage may reduce the incidence of developing oral carcinoma.

The role of epithelial-mesenchymal transition in oral squamous cell carcinoma and oral submucous fibrosis

Epithelial-mesenchymal transition (EMT) is an indispensable mechanism during morphogenesis. Interest and research in EMT are currently at a high level due to its important role in cancer and fibrosis. Emerging evidence suggests that EMT is also a crucial event in oral squamous cell carcinoma (OSCC). Oral submucous fibrosis (OSF) is a chronic debilitating disease and a premalignant condition of the oral cavity. It is characterized by a generalized submucosal fibrosis. The pathogenesis of the disease is not well established. Epidemiological evidence strongly indicates an association between the betel quid (BQ) chewing habit and OSF. In a simplistic view, OSF represents a failed wound-healing process of the oral mucosa after chronic, sustained injury. This review highlights the signaling pathways involved in EMT, recent advances in the study of EMT in OSCC, and summarizes the evidence supporting a role for EMT in the pathogenesis of OSF.

Development of an in vivo mouse model to study oral submucous fibrosis

BACKGROUND

Epidemiological data have shown an association of areca nut chewing with oral submucous fibrosis (OSF). Experimental evidence to confirm this has been limited. Fibrosis-promoting activity of areca nut was tested in an animal model.

METHOD

Buccal mucosa of a group of 20 female BALB/c strain mice, 10-12 weeks of age, was treated twice daily 6 days per week with topical application of aqueous areca nut extracts for 300-600 days. A control group (n = 20) was treated with 50 mM NaCl. The influence of areca nut on the oral epithelium and connective tissue was recorded semiquantitatively by light microscopy.

RESULTS

The areca nut-treated oral epithelium showed progressive changes in epithelial thickness leading to atrophy, increased cellularity of fibroblasts, fibrosis of connective tissue, focal infiltration of inflammatory cells and muscle atrophy. On killing after 600 days of treatment, the scores on cellularity, inflammation and muscle atrophy were significantly different to the control group (P = 0.03).

CONCLUSION

The study provides further evidence that areca nut contributes to the development of OSF in treated animals. The model has the potential to test synergism of areca nut with other carcinogens and any therapeutic interventions.