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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.
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.
Oral Sub-Mucous Fibrosis Classification