(J.J Pindborg and Sirsat 1966)
It is an insidious chronic disease affecting any part of the oral cavity and sometimes the pharynx. Although occasionally preceded by and /or associated with vesicle formation ,it is always associated with juxta-epithelial inflammatory reaction followed by a fibro-elastic changes of the lamina propria with epithelial atrophy leading to stiffness of the oral mucosa and causing trismus and inability to eat.
First described among five East African women of Indian origin under the term Atrophia idiopathica (tropica) Mucosae Oris by Schwartz 1952
Joshi in 1953 is credited to be the first person who described it and gave the present term “Oral sub-mucous fibrosis”.
In the year 1954, Su. 1. P. from Taiwan described similar condition, which he called “Idiopathic Scleroderma of mouth”
OSMF is a crippling fibrotic disorder seen commonly in India and Indian subcontinent. Sporadic cases are seen in Malaysia, Nepal, Thailand and South Vietnam.
Incidence of OSMF in India is 0.2-0.5% of population.
Persons between 20 and 40 years of age are most commonly affected ,but ages have ranged from 2 to 89 years of age
No cast or religious community is especially affected
Etiology of OSMF:
Exact etiology is unknown. The suggested factors are,
1. Chronic Irritation
2. Deficiency disease.
3. Defective iron metabolism
4. Bacterial Infection
5. Collagen disorder
6. Immunological disorders
7. Genetic disorder.
Pathogenesis of OSMF lies in the continuous action of mild irritants.
“Capsaicin” a active extract from capsicum.
The active principle irritant of chillies (Capsicum annum and Capsicum frutescence) .
The suspicion that chilli is an etiological agent arose on the basis of ecological observations and was strengthened by the clinical and histological characteristics of this condition , i.e.
Tissue eosinophils in the biopsy specimen and presence of sub epithelial vesicles
suggested an allergic nature of this disease possibly due to chilli intake.
There are some ecological arguments against the chilli hypothesis for example from Mexico or other South American countries where chilli consumption is widespread, there is no report of this condition.
The overall assessment is that there is no evidence substantiating the etiologic role of chilli in OSMF
Betel nut & lime mixture is used for chewing. This also contains arecoline, lime and tannic acid, These cause local irritation and damage to the mucosa with vesicle and ulceration on susceptible individual.
Lime in betel quid causes constant aberration of oral mucosa, allowing direct access to the carcinogens
It is a known irritant and a causative factor in oral malignancies
N’-nitrosonornicotine is produced by bacterial and enzymatic nitrosation of nicotine and can be found by reaction of salivary nitrates with nornicotine
N’-nitrosonornicotine levels increased 44% when tobacco was mixed with saliva
N’-nitrosonornicotine extracted from chewing tobacco with saliva is approximately 1000 times that found in cigarette smoke
Considered to be one of important etiological factor for OSMF
In India arecanut is chewed by itself or in the form of various areca nut preparations such as supari, mawa , manipuri , pan masala and in betel quid either with or without tobacco
The factors that contribute to the pathogenesis in habitual betel nut chewers.
1. The amount of tannic acid (14-18%)
contained in the betel nut.
2. The influence of mixed calcium powder.
3. Action of arecoline contained in the betel nut affecting the vascular nerve of oral mucosa and causing neurotropic disorder
Arecanut contain different type of alkaloids- arecoline, arecadine, guvacoline, guvacine and isoguvacine.
Nitrosation of arecoline leads to the formation of arecanut specific nitrasamine. All arecanut specific nitrosamines are found to be powerful carcinogens and alkylate DNA.
KHANNA AND ANDHARA , have suggested pathogenesis of OSMF by dual action of arecanut. They suggested that ,
Arecoline , stimulate fibroblastic proliferation and collagen synthesis.
The flavonoids catechin and tannins stabilize the collagen fibrils rendering them resistant to degradation by collagenase.
The attendent trismus is a result of juxtaepithelial hyalinization and secondary muscle involvement (i.e. muscular degradation and fibrosis)
The habit of chewing areca nut leads to muscle fatigue
Vitamin B12 and Iron deficiency are associated with OSMF. The deficiency could be due to the fact that defective nutrition due to impaired food intake in advanced cases of OSMF, may be the effect rather than the cause of the disease
The data regarding the sex predilection is conflicting. Earlier it was thought to be common in females.
But at present ,study ratio shows 2.3: 1 =M:F
Age group common is 2 to 3rd decade of life
But cases have been reported from 4 year to 86 yrs
Prodromal symptoms :
Onset is insidious. The most common initial symptoms are:
Burning sensation on eating spicy food
Blisters on the palate
Ulceration or recurrent stomatitis
Defective gustatory sensation
Dryness of mouth.
Difficulty in opening mouth
Inability to whistle, blow
Difficulty in swallowing
When fibrosis involves pharynx- referred pain to the ear.
Changes in tone of the voice due to vocal cord involvement
Some times deafness due to occlusion of eustachian tubes