A Clinico-histopathological Study of Association between Fibrosis and Mouth Opening in Oral Submucous Fibrosis

Oral submucous fibrosis (OSF) is a common premalignant condition of the mouth with areca nut chewing habit in the Asian subcontinent. It is characterized by restricted mouth opening, tongue protrusion and cheek flexibility. Though there are many histological studies of OSF reporting fibrosis and hyalinization in the sub-epithelium, there is a paucity of information related to the association of fibrosis and mouth opening (MO) and muscle changes in this condition. The present study was undertaken to study the association between mouth opening and fibrosis ; and to study the degree of alterations involving muscle fibers as the disease progresses. However, the statistical analysis showed that there is no correlation between stage of mouth opening and grading of fibrosis as suggested by the insignificant ‘p’ value.     

A light microscopic study of fibrosis involving muscle in oral submucous fibrosis.

Oral submucous fibrosis (OSF) is a common pre-malignant condition of the mouth in arecanut chewers in Indian subcontinent. It is characterized by restriction in opening of the mouth, tongue protrusion, and cheek flexibility. Reports of muscle changes in OSF, using light microscopy are few. Incisional biopsy sections of thirty OSF patients were stained with Masson's Trichrome stain, to study the fibrosis involving the muscle. Wide spectrum of changes were observed where fibrosis was being evident sub-epithelially, not extending in to the muscle to cases where only a few remnants of muscle fibers were seen and the missing muscle bundle area being replaced by fibrous tissue. The probable mechanism by which these changes occur is discussed.     

槟榔碱及机械刺激构建大鼠口腔黏膜下纤维化模型

目的 利用槟榔碱和机械刺激构建Sprague-Dawley（SD）大鼠口腔黏膜下纤维化（OSF）模型。方法 采用两因素析因实验设计将48只大鼠分为8个组,每组6只。分别用不同浓度（0、0.5、2、8 mg·mL ^-1）槟榔碱涂擦及机械刺激 (有或无毛刷涂擦)。处理16周后测量开口度;取局部颊黏膜行苏木精-伊红（HE）染色观察病理变化;并检测组织内Ⅲ型胶原、转化生长因子-β1（TGF-β1）和γ干扰素（IFN-γ）的表达情况。结果 2和8 mg·mL ^-1（中、高）浓度槟榔碱处理16周,颊黏膜出现了典型的OSF病理特征;开口度显著减小并且Ⅲ型胶原、TGF-β1表达显著增加（P<0.05）。机械刺激虽可导致黏膜Ⅲ型胶原、TGF-β1和IFN-γ表达增高（P<0.05）,但无病理学改变,开口度改变不显著。结论 中、高浓度槟榔碱有致OSF作用;机械刺激无法导致大鼠OSF的发生。     

槟榔碱及机械刺激构建大鼠口腔黏膜下纤维化模型

目的 利用槟榔碱和机械刺激构建Sprague-Dawley（SD）大鼠口腔黏膜下纤维化（OSF）模型。方法 采用两因素析因实验设计将48只大鼠分为8个组,每组6只。分别用不同浓度（0、0.5、2、8 mg·mL ^-1）槟榔碱涂擦及机械刺激 (有或无毛刷涂擦)。处理16周后测量开口度;取局部颊黏膜行苏木精-伊红（HE）染色观察病理变化;并检测组织内Ⅲ型胶原、转化生长因子-β1（TGF-β1）和γ干扰素（IFN-γ）的表达情况。结果 2和8 mg·mL ^-1（中、高）浓度槟榔碱处理16周,颊黏膜出现了典型的OSF病理特征;开口度显著减小并且Ⅲ型胶原、TGF-β1表达显著增加（P<0.05）。机械刺激虽可导致黏膜Ⅲ型胶原、TGF-β1和IFN-γ表达增高（P<0.05）,但无病理学改变,开口度改变不显著。结论 中、高浓度槟榔碱有致OSF作用;机械刺激无法导致大鼠OSF的发生。     

Limited mouth opening in oral submucous fibrosis: reasons,ramifications, and remedies

Limited mouth opening (LMO) in oral submucous fibrosis (OSF) has been attributed to both the submucosal and muscle fibrosis (MF). While reflectory trismus was proposed before as an auxiliary mechanism by another group, the stretch‐mediated muscle damage (MSD), histopathological changes in blood vessels (such as endothelial dysfunction, endothelial hypertrophy, and endarteritis obliterans), and upregulated anaerobic isoforms of lactate dehydrogenase (LDH) have been proposed by us as complementary events leading to MF. Additionally, the amount of hypoxia‐mediated upregulation of anaerobic isoforms of LDH determines the extent of MF. Radiotherapy (RT)‐mediated release of reactive oxygen species causes vascular damage thereby worsening hypoxia. While the alteration in LDH levels secondary to hypoxia enhances fibrosis, RT worsens it. Oral squamous cell carcinoma occurring in the background of OSF is an absolute contraindication for RT as it augurs unfavorable prognosis. An algorithm to demonstrate this with evidence is clearly depicted. The role of HIF‐1α in the progression of OSF and its malignant transformation, and the consideration of hyperbaric oxygen therapy as a therapeutic remedy in OSF are underscored.     

Interferon gamma (IFN-γ) may reverse oral submucous fibrosis

Oral submucous fibrosis (OSF) is a chronic disease of the oral cavity and oropharyngx characterised by fibrosis in the submucosa leading to progressive limitation of the mouth opening. Interferon gamma (IFN-gamma) is a known anti-fibrotic cytokine. In this study we have investigated: a) the effect of IFN-gamma on collagen synthesis by arecoline-stimulated OSF fibroblasts in vitro (n=5), b) the effect of intra-lesional IFN-gamma on the fibrosis of OSF patients (n=29) and c) the immunohistochemical analysis of pre- and post-treatment inflammatory cell infiltrates and cytokine levels in the lesional tissue (n=29). The results show that the increased collagen synthesis in vitro in response to arecoline was inhibited in the presence of IFN-gamma (0.01-10.0 U/ ml) in a dose-related way. In an open uncontrolled study intra-lesional IFN-gamma treatment showed improvement in the patients mouth opening from an inter-incisal distance before treatment of 21 +/- 7 mm, to 30 +/- 7 mm immediately after treatment and 30 +/- 8 mm 6-months later, giving a net gain of 8 +/- 4 mm (42%) (range 4-15 mm). Patients also reported reduced burning dysaesthesia and increased suppleness of the buccal mucosa. The post-treatment immunohistochemistry showed a decreased amount of inflammatory cell infiltrate and an altered level of cytokines compared with the pre-treatment lesional tissue. The effect of IFN-gamma on collagen synthesis appears to be a key to the treatment of these patients, and intra-lesional injections of the cytokine may have a significant therapeutic effect on OSF.     

Distribution of procollagen type III, collagen type VI and tenascin in oral submucous fibrosis (OSF)

The distribution of procollagen type III, collagen type VI and tenascin was studied in biopsy specimens from the buccal mucosa of 19 Indian women with confirmed oral submucous fibrosis (OSF) using the immunogold-silver staining technique. Immunohistochemistry revealed a loss of stainable procollagen type III and collagen type VI in the fibrotic zones of oral submucous fibrosis compared to normal oral mucosa. Tenascin was noted only very faintly at the subepithelial basement membrane. The present study showed that procollagen type III and collagen type VI in OSF were expressed in a specific pattern which allows a clear differentiation between fibrotic areas and adjacent apparently normal connective tissue stroma. Loss of procollagen type III, and therefore a probable predominance of collagen type I in collagen fiber bundles, and an almost complete loss of collagen type VI might explain the stiffness of the oral mucosa in patients with OSF. The immunohistochemical findings provided evidence that the process of fibrosis starts in the deeper subepithelial connective tissue stroma and not close to the subepithelial basement membrane. Further studies are required to determine whether OSF is due to increased or altered synthesis and deposition of extracellular matrix proteins, altered fibrolysis or both.     

The role of basic fibroblast growth factor in oral submucous fibrosis pathogenesis

Background:  Oral submucous fibrosis (OSF) is a chronic fibrotic disease of oral mucosa and oropharynx, induced by betel quid chewing often resulting in restricted mouth opening. The principal cells implicated as a source of extracellular matrix in areas of fibrosis are fibroblasts. Accumulation of connective tissue matrix is secondary to factors such as cytokines and growth factors. The contribution of basic fibroblast growth factor (bFGF) in disease progression and the consequent stromal changes with increase in the severity of OSF was studied.
Methods:  A case series analysis of 30 cases of OSF was carried out for bFGF expression using immunohistochemistry. Connective tissue changes in these cases were corroborated using aldehyde fuchsin and Verhoeff's hematoxylin special stains.
Results:  bFGF immunoreactivity was found to be increased in fibroblasts and in endothelial cells in early OSF cases, while the expression of bFGF in stroma increased notably in advanced fibrosis.
Conclusion:  Increased bFGF expression in early stages of the disease was explainable to an initial injury phase because of areca consumption, followed by cellular activation by chemotactic cytokines and other growth factors with eventual fibrosis occurring as a result of molecular alteration at the cellular level.     

Oral submucous fibrosis, a clinically benign but potentially malignant disease: report of 3 cases and review of the literature

Oral submucous fibrosis (OSF) is a premalignant condition mainly associated with the practice of chewing betel quid containing areca nut, a habit common among South Asian people. It is characterized by inflammation, increased deposition of submucosal collagen and formation of fibrotic bands in the oral and paraoral tissues, which increasingly limit mouth opening. Recently, OSF has been reported among South Asian immigrants in Canada, the United Kingdom and Germany. Dentists in western countries should enhance their knowledge of this disease as it seems to be increasing with population migration. In this paper, we review the literature on OSF and present 3 cases representing different stages of the disease to help dentists make an early diagnosis and reduce the morbidity and mortality associated with this condition.     

Molecular pathogenesis of oral submucous fibrosis – a collagen metabolic disorder

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 evidences strongly indicate the association of the betel quid (BQ) habit and OSF. Various findings indicate the disease to be a consequence of disturbances in the homeostatic equilibrium between synthesis and degradation of extracellular matrix (ECM), wherein collagen forms a major component, thus can be considered as a collagen-metabolic disorder. Transforming growth factor-beta (TGF-beta) is a potent stimulator of production and deposition of the ECM. The objectives of this review are to highlight the molecular events involved in the overproduction of insoluble collagen and decreased degradation of collagen occurring via exposure to BQ and stimulation of the TGF-beta pathway, and elucidate the cell signaling that is involved in the etiopathogenesis of the disease process.     

异种脱细胞真皮基质修复膜在口腔黏膜下纤维性变手术治疗中的应用

目的:评价异种脱细胞真皮基质修复膜在口腔黏膜下纤维性变手术治疗中的应用效果。方法:8例重度口腔黏膜下纤维性变患者,经鼻腔气管插管全麻下切除双侧颊部翼下颌韧带前方区域纵行的纤维条索,术中被动开口度达正常范围后,剪取相应大小的异种脱细胞真皮基质修复膜覆盖黏膜缺损创面,间断缝合后,碘纺纱包加压固定。术后10～14d拆除纱包与缝线后开始开口训练,定期随访并进行类固醇皮质激素黏膜下局部注射等辅助治疗,通过伤口愈合、瘢痕软化及开口度改善等指标评价手术效果。采用SPSS16.0软件包对数据进行单因素方差分析。结果:8例患者双侧颊部纤维条索切除后形成的手术创面,采用异种脱细胞真皮基质修复膜进行修复均获得成功,无感染或排异等并发症发生。术后随访6～18个月,患者颊部原手术区黏膜红润,质地柔软,开口困难明显改善。术前开口度为(12.04±2.93)mm,术中开口度为(35.46±3.17)mm,术后6个月时的开口度为(29.33±4.28)mm,经统计学分析,差异具有显著性(P<0.05)。结论:应用异种脱细胞真皮基质修复膜修复重度口腔黏膜下纤维性变手术治疗中的黏膜缺损创面,能够起到促进创面早期愈合、减轻瘢痕形成与改善开口困难的作用,其操作简单易行,值得临床推广应用。     

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.     

Orale submuköse Fibrose bei einer 31-jährigen Inderin

Background

Oral submucous fibrosis (OSF) is a chronic disease characterized by subepithelial collagen deposition with formation of bands involving the oral cavity and adjacent structures. Oral submucous fibrosis is a precancerous condition. It is caused by chewing of betel quid (Areca catechu L., Piper betle, lime and tobacco) and ready-made products like pan masala and gutka which also contain areca nut. These products are available all over South Asia. The hallmark of OSF is extremely restricted mouth opening.

Case report

A 31-year-old Indian woman who has lived in Germany since 1997 presented herself because of limitation of mouth opening. She reported that she has chewed pan masala and gutka since she was 17 years of age. History, clinical and histological findings clearly pointed to the diagnosis of OSF.

Discussion

Conservative as well as surgical interventions for OSF have not resulted in adequate long-term results. Since OSF may occur in children and young adults, the primary aim should be to avoid progression of the disease, initially by physiotherapy. Surgical interventions should not be applied at an early stage of the disease because recurrences and further surgical interventions are often necessary. Due to the increasing numbers of migrants from South Asia more cases of OSF will probably also be observed in Germany, where areca nut-containing products are also available.     

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口腔黏膜下纤维性变(oral submucous fibrosis,OSF)是一种慢性、隐匿性、具有癌变倾向的口腔黏膜疾病。其主要临床表现为口腔黏膜纤维化、进食刺激性食物时口内疼痛,严重者可致张口和进食困难。目前,OSF的诊断手段主要包括临床检查和病理诊断。本文旨在结合笔者的临床经验和最新的相关文献,评述OSF诊断方法的研究进展,如分子生物学方法在OSF诊断中的应用、OSF合并症的诊断等。     

口腔黏膜下纤维性变中MMP-2基因的表达及意义

目的：检测口腔黏膜下纤维性变中基质金属蛋白酶-2（MMP-2）的表达并探讨其病理意义.方法：抽提11例口腔黏膜下纤维化组织和10例正常口腔黏膜组织的总RNA,通过逆转录聚合酶链反应（PF-PCR）检测MMP-2mRNA在口腔黏膜下纤维性变患者颊黏膜中的表达并与正常口腔黏膜进行比较.结果：口腔黏膜下纤维性变患者颊黏膜组织中MMP-2 mRNA表达高于正常颊黏膜（p＜0.05）.结论：MMP-2基因的表达与口腔黏膜下纤维性变组织重塑过程密切相关.     

Physiotherapeutic treatment improves oral opening in oral submucous fibrosis

Background:  In oral submucous fibrosis (OSF) fibrous bands and burning mucosal pain restrict oral opening to limit speech and eating. The pathogenesis of OSF remains unclear, while surgical and pharmacological treatments have limited success, and are often inaccessible in communities using areca nut where OSF is prevalent. Improved outcomes are reported for surgical treatment when followed by physiotherapy. We tested the hypothesis that physiotherapy alone can modify tissue remodelling in OSF to increase oral opening.
Materials and methods:  Fifty-four Nepali OSF patients were managed for 4 months in three randomly assigned groups receiving either: five times daily physiotherapy by inter-positioning tongue spatulas between teeth and adding a new spatula every 5–10 days; local injection of hyaluronidase with steroids; or no active treatment.
Results:  More males presented with OSF than females ( p  < 0.05). All patients reported reduced opening and 47% had mucosal pain. Progressive mucosal involvement was always in the same order, starting with the soft palate, and then progressing to the fauces, unilateral buccal mucosa, bilateral buccal mucosa, floor of mouth and finally lip mucosa ( p  < 0.006). Physiotherapy improved oral opening ( p  < 0.0005), but not oral pain, while no clear improvement was seen in untreated patients as well as patients managed by injection.
Conclusions:  We conclude OSF in the Nepali population progresses in a predictable pattern, and that physiotherapy is effective for increasing the oral opening. We further suggest physiotherapy can be readily used to improve OSF in communities with otherwise limited health resources.     

口腔粘膜下纤维性变临床分型探讨

目的：为提高口腔粘膜下纤维性变（ＯＳＦ）的临床检出率和诊断率。方法：对湖南省湘潭市１１０４６人进行口腔普查将检出的３３５名ＯＳＦ患者按不同临床表现分为弥漫型和局限型,其中具有ＯＳＦ典型临床表现者为弥漫型,其它为局限型,并于１０年后复查了其中７２名患者。结果：３３５名患者中弥漫型仅１３例,占３．９％,局限型３２２例,占９６．１％。复查显示：在无适当治疗下,两型之间无相互转化。结论：局限型ＯＳＦ是湘潭     

口腔黏膜下纤维性变的病因、致病机理、诊断与治疗

口腔黏膜下纤维性变是一种能形成瘢痕、组织纤维化的慢性疾病。流行病学研究显示,咀嚼槟榔是导致口腔黏膜下纤维性变的危险因素。在中国的口腔黏膜下纤维性变患者均有咀嚼槟榔的习惯。研究证实,嚼槟榔、吸烤烟和饮白酒可增加口腔黏膜下纤维性变的风险。口腔黏膜下纤维性变被广泛认为是一种口腔癌前病变,病理表现为慢性炎症、结缔组织内广泛的胶原纤维沉积、上皮固有层或其下结缔组织内的局部炎症改变。口腔黏膜下纤维性变的癌变发生率为7%~30%。口腔黏膜下纤维性变的治疗主要采用曲安奈德和丹参酮注射液行黏膜下局部注射,对改善患者的张口度及口腔黏膜的烧灼痛效果良好,其治疗总有效率可达93%。本文就口腔黏膜下纤维性变的病因、致病机理、诊断与治疗进行阐述,以供同道们临床参考之用。     

Histologic examination of pedicled buccal fat pad graft in oral submucous fibrosis.

PURPOSE: This report evaluates the wound healing process of buccal fat pad (BFP) grafted on a defect of the buccal mucosa for oral submucous fibrosis (OSF). PATIENTS AND METHODS: Sixteen patients with limitation of mouth opening under the diagnosis of OSF were surgically treated by cutting the fibrotic bands on the buccal mucosa (10 bilateral and 6 unilateral). The defects created were then covered by a BFP graft. The bulging BFP was trimmed postoperatively on a weekly basis until it was fully epithelialized. The specimens were stained and examined microscopically. RESULTS: Inflammatory cell infiltrate, blood vessel congestion, and fibrinous exudates covering the BFP were obvious by week 2. At week 3, blood vessel congestion and fat cell number decreased markedly. Evidence of stratified squamous epithelium with parakeratosis was seen in the margin of the BFP graft. At week 4, the number of fat cells decreased significantly and the original BFP was almost completely replaced by granulation tissue. The original BFP was fully covered by stratified squamous epithelium by week 5. CONCLUSIONS: The BFP graft has been widely used for covering exposed defects created by fibrotic band excision for the improvement of mouth opening limitation. The healing process was documented microscopically by weekly observation.     

Oral submucous fibrosis: a clinico-histopathological study in Chennai.

BACKGROUND: Oral submucous fibrosis (OSF) is a precancerous condition associated with the use of areca nut in various forms. There are very few reports to correlate the clinical stage to histopathological grading in OSF. MATERIALS AND METHODS: A hospital-based study was conducted on 75 OSF cases who visited our hospital in Chennai from 2000-2003. A detailed history of each patient was recorded along with a clinical examination. Biopsy was performed for histopathological correlation. Clinical stage of the disease in terms of the ability to open one's mouth was correlated with histopathological grading. RESULTS: The male to female ratio of OSF cases was 6:1. All forms of areca nut products were associated with OSF. Chewing of paanmasala was associated with early presentation of OSF as compared to chewing of the betel nut. Out of 57 cases, which were in clinical stage II, 91.2% had histological grading of I and II in equal proportions and 8.8% had histological grade III. Out of 13 cases that showed a clinical stage of III, 52% showed a histological grade of II, 40% grade III and 8% grade I. CONCLUSION: In the present study, there was no direct correlation between clinical stages and histopathological grading. The possibility of difference in the severity and extent of fibrosis in different regions of the oral mucosa and involved muscles were considered as contributory factors for this variation.