Study population and methods

2.3.1 Study population 2.3.1.1 In Bangladesh

All betel quid or areca quid, tobacco quid and areca nut chewers, who attended the out patients clinic in DDCH, Dhaka and the special health care clinics during the period of January to December 1995 were examined. They attended the out patients clinic in DDCH and special health care clinics for their dental problems self-referred or referred by their general medical doctor. When their habit history and clinical examination revealed the chewing of betel quid then they were screened for this study.

2.3.1.2 In London

Screening of the mouth of all accessible betel quid chewers in the UK was done in six primary health care clinics (GMP surgeries) in London. The centres were- 1) King’s Cross Surgery in west central, 2) Bethnal Green Health centre 3) Spitalfields Health Centre and 4) East India Dock Road Practice in east and 5) Falmouth Road Group Practice and 6) Borough Road Practice in south-east of London. The betel quid chewers were invited by displaying posters explaining the harmful effects of betel quid chewing at the premises of GMP surgery. Some of the chewers attended the mouth-screening clinic on their own and the others referred by their GMPs. The chewers were referred for minor dental problems or sometimes only for their mouth screening. Most of the chewers attended in these health centres are originally from Indian sub-continent predominantly from Bangladesh and domiciled in this country. Screening was conducted during the period of October 1993 to June 1994.

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2.3.2 Methods

2.3.2.1 Examination of the chewers

All the betel quid chewers both in Bangladesh and in London were examined for both intra- and extra-oral mouth problems along with a full dental history. Inter- incisal mouth opening and other mouth problems, like burning sensation, diminished taste sensation and blanching of the oral mucosa were recorded. Tooth decay and periodontal disease were not recorded in this survey. Detailed history of chewing betel quid or quids of any other form was recorded. The examination of the chewers’ mouth was carried out by Dr. Anowar Hussain, a member of this research team in DDCH, Dhaka, Bangladesh and by myself in London in a pre-formed questionnaire (Appendix 2.1) on the basis of the diagnostic criteria mentioned below. The calibration of the examination was done to maintain the uniformity of the patient examination and diagnosis of OSF in these two centres by frequent discussions by letter and telephone with Dr. Anowar Hussain in Bangladesh, maintaining the criteria mentioned in the diagnostic criteria for identification and diagnosis of OSF and different types of quids.

2.3.2.2 Diagnostic criteria

Several previous studies mentioned that chewing of betel quid may cause a number of mucosal lesions/ conditions including OSF or quid of some other forms (Sirsat and Khanolkar 1962, Pindborg and Sirsat 1966). For the purpose of this thesis, the diagnostic criteria for the recognition of OSF and classification of quids made in the past are discussed here. Pindborg et al. (1964), Pindborg (1965) and Rajendran (1994) described the presence of palpable fibrous bands with limited mouth opening as a clinical criterion for the diagnosis of OSF. Some other studies (Mehta et al. 1971, Pindborg et al. 1968) mentioned that apart from the presence of fibrous bands in the cheek, a range of other clinical symptoms are also important to characterise this condition. These are tough leathery mucosa and blanching of the oral mucosa.

‘Betel quid’ (areca nut, betel leaf, slaked lime, tobacco) is synonymous with ‘pan’ and it is one the most common recipes of the habit of quid chewing in different parts of the world. Previous epidemiological studies mentioned that some of the constituents of betel quid (areca nut, tobacco) could be used alone

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by themselves or in various combinations with other ingredients without the use of betel leaf (Pindborg and Sirsat 1966). A recent Workshop held in Malaysia has published consensus guidelines and recommendations in this regard (Zain et al. 1997), but this study was conducted long before this Workshop and publication. Therefore, the diagnostic criteria for the recognition of OSF and classification of the quids are made on the basis of the previous clinical and epidemiological studies, and are mentioned below.

Oral submucous fibrosis:

At least two of the following characteristic features are included for the diagnosis of OSF.

a) Mouth opening <30mm inter-incisal distance. It has been clinically observed that the lower limit of mouth opening in a normal mouth condition and class I arch relationship is around 30 mm. In cases of Class II division II skeletal relationship the mouth opening is observed less than 30 mm even in a healthy mouth. So, 30 mm has been taken as a lower limit of normal healthy mouth opening unless accompanied by

b) Palpable fibrous bands,

c) Tough, leathery mucosal texture, c) Blanching of the oral mucosa and

d) Diminished taste or altered oral sensation i.e. sore mouth or burning sensation.

Betel quid:

Classification of quids-

a) Betel quid- quid containing areca nut, betel leaf, slaked lime and tobacco products,

b) Areca quid- quid containing all the constituents of betel quid except tobacco products,

c) Tobacco quid- quid containing all the constituents of betel quid except areca nut and

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2.3.2 3 Investigations

The chewers in London who complained of chewing difficulty, burning sensation and diminished taste and where clinical examination revealed ulcers in the tongue and/or in the cheek, were referred for haematology and blood chemistry (Full blood count, serum and red cell folate, Vitamin B12 and iron deficiency). Blood investigations for the chewers in Bangladesh were not done because of the limitation of the resources.

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