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Oral Sub-Mucous Fibrosis
Definition

Oral Sub-mucous Fibrosis (OSF) is a well-recognised oral pre-cancerous condition, observed predominantly in
populations of South Asian ethnic origin.  It predominantly occurs in the Indian sub-continent and people of South
Asian ethnicity living in other countries such as the UK, Singapore and Malaysia, among others.

It is characterised by a unique
generalised fibrosis (scarring) of the sub-mucosal oral soft tissues, resulting in
marked rigidity of the
oral mucosa leading to progressive trismus (inability to open the mouth), rigidity of lips and
difficulty in protruding the tongue.


Ætio-Pathogenesis:

Risk Factors:

  • areca nut chewing ± tobacco
  • capsaicin in chilies and
  • micro-nutrient deficiencies of iron, zinc and essential vitamins.

An increase in the frequency of this disease, especially among the young, has been reported in India due to the
increase in the use of commercially prepared
areca nut preparations without betel leaf (pan masala).

A genetic predisposition for the development of this disease has also been reported.


The
areca nut, which contains alkaloids such as arecoline, and other chemicals, such as catechin and tannin, plays
a major role by stimulating production of
collagen fibres and making them less susceptible to the action of
collagenase (an enzyme that breaks down collagen).

It is suggested that components of the
areca nut also affect gene expression in the fibroblasts leading to the
production of greater amounts of normal
collagen.  Areca nut has been shown to have a high copper content, and
chewing
areca nuts for 5 – 30 minutes significantly increases soluble copper levels in oral fluids. This increased
level of soluble copper supports the hypothesis that copper acts as an initiating factor in
OSF by stimulating
fibrogenesis.

It is not clear if a
hypersensitivity reaction to chillies plays any role in the development of OSF.

Iron deficiency anæmia, vitamin B complex deficiency and  malnutrition are implicated in the development of OSF
leading to deranged repair processes of the inflamed oral mucosa, contributing to defective healing and scarring.
Photo of palate showing the development of OSF with the lustre-less, marble-like blanching of the oral mucosa.
Diagnosis

A clinical diagnosis of OSF is made based on the symptoms and clinical features described above.  A biopsy should
be taken to confirm the diagnosis and to rule out
dysplasia and malignancy.


Management

  • Cessation of habits
  • Correction of nutritional deficiency
  • Mouth opening exercise
  • Oral lycopene (anti-oxidant found in tomatoes)
  • Sub-mucosal injections of steroids, hyaluronidase, collagenase & placental extract
  • Surgical removal of fibrous tissues & use of tissue grafts

The treatment of patients with OSF depends on the degree of clinical involvement.

If the disease is detected at a very early stage, cessation of the habit is effective.  However, it is often irreversible
in
OSF patients who present with severe disease.

The focus of treatment should be on reducing exposure to the risk factors, especially the use of
betel quid and
correcting any nutritional deficiencies, such as iron and
vitamin B complex and on regular mouth opening exercises.

Muscle stretching exercises for the mouth may be helpful to prevent further limitation of the mouth opening.

Sub-mucosal injections of agents such as dexamethasone, hyaluronidase, placentral extracts and collagenase
have been tried with some benefit in symptomatic improvement.

Excision of the
fibrous tissues, with correction of the defect using various grafts especially with buccal fat pad graft,
has been tried in patients with severe
OSF.

Lycopene has been shown to be of some benefit.

In general, there is no effective treatment for
OSF and the condition is irreversible once fibrosis sets in.  Even
though several treatment regimens have been tried with varying success, so far no effective treatment is available
for
OSF.


Useful Websites:

New Zealand Dermatological Society (DermNZ)

Emedicine

Wikipedia

International Agency for Research on Cancer / World Health Organisation

Bond's Book of Oral Diseases, 4th Edition


Useful Articles:

Cochrane Review 2008.  Interventions for the Management of Oral Sub-Mucous Fibrosis

J Oral Maxillofac Surg 2009.  Drug Treatment of Oral Sub-Mucous Fibrosis - A Review of the Literature

BJOMS 2009. Extended Naso-Labial Flaps in the Management of Oral Sub-Mucous Fibrosis

Evidence-Based Dentistry 2009.  Lack of Reliable Evidence for Oral Submucous Fibrosis Treatments

Evidence-Based Dentistry 2010.  Drug Treatment for Oral Submucous Fibrosis

JOMS 2011.  Use of Buccal Fat Pad for Treatment of Oral Submucous Fibrosis
Last Updated 26th November 2016
Iron deficiency anæmia, vitamin B complex deficiency and malnutrition are implicated in the development of OSF
leading to deranged repair processes of the inflamed
oral mucosa, contributing to defective healing and scarring.

The resulting
atrophic oral mucosa is more susceptible to the effects of areca nut and alcohol.  An immunological
process and a genetic component are assumed to be involved because of reported cases in non–
areca nut
chewers.  Increased levels of
pro-inflammatory cytokines and reduced anti-fibrotic interferon have also been
demonstrated in patients with
OSF.
Clinical Features:

Clinically, patients present with a lustre-less, marble-like blanching of the
oral mucosa.

In the early stages, features of
stomatitis such as erythematous (reddened) mucosa, vesicles (blisters), mucosal
ulcers
, blotchy melanotic mucosal pigmentation (like freckles) and mucosal petechiæ (bruising) may be observed.
Role of Areca Nut in Pathogenesis of Oral Sub-Mucous Fibrosis
As the disease advances, vertical and circular fibrous bands may be palpated in the buccal mucosa and around
peri-commissural area.  A mottled, marble-like appearance may be evident due to the bands running in the
blanched
mucosa.

In advanced disease, there is
trismus, sinking of the cheeks out of proportion to age, stiff and small depapillated
tongue
, blanched floor of mouth, fibrotic (scarred) gingival tissues, stiff soft palate with reduced mobility and
shrunken bud-like
uvula and blanched and atrophic tonsils.

> 25% of affected persons may have co-existing
leukoplakia.  The buccal mucosa is the most commonly involved
site, followed by the lip and tongue but
OSF can occur in any intra-oral site.

The frequency of
malignant transformation in OSF has been reported to be in the range of 7 – 13%.  Whether
the
malignant transformation is more common in leukoplakic areas than non-leukoplakic areas in patients with
OSF is not clear.