[A study on the clinical classification of oral submucous fibrosis]

To increase the positive rate and sensitivity of the diagnosis for oral submucous fibrosis (OSF).

A general oral survey of 11,046 persons was carried out in Xiangtan, Hunan. According to Pindborg's diagnostic standard to epidemiological studies of OSF, 335 cases of OSF were found. The prevalence was 3%. According to different clinical manifestations, 335 cases of OSF were divided into two types: diffuse type and localized type. The cases with typical features of OSF, such as burning pain and discomfort, dryness of the mucosa, progressive inability to open the mouth and presence of palpable bands in the oral mucosa and so on, were in the diffuse type. Those with non-typical features, only having presence of palpable bands in the oral mucosa, were in the localized type. 72 cases were followed-up for ten years.

335 cases of OSF were divided into two types. 13 cases (3.9%) were in the diffuse type, and 322 cases (96.1%) were in the localized type. Most of the OSF in this region belonged to the localized type. It was also discovered that without proper treatment, the subjects sticked to one type of OSF without changing from one type to another after ten years of follow-up.

Localized type of OSF is the major type of OSF in Xiangtan. It is an independent clinical type. To classify OSF, it is good for the clinicians to pay attention to non-typical OSF. If the non-typical OSF cases are taken into consideration, the prevalence of OSF will increase considerably.