Relevance. The prevalence of oral mucosal diseases among the Russian population varies from 3% to 20% [7]. Precancerous and malignant diseases are a particular problem. More than nine thousand new cases of malignant oral mucosal lesions are registered annually in the Russian Federation, and yearly mortality rates reach 34%. Unfortunately, despite being externally located, the rate of late-diagnosed malignant oral mucosal neoplasms reaches 60%-70% in various regions of the Russian Federation [2]. Thus, one of the most urgent problems in dentistry and oncology is the early diagnosis of precancerous and malignant oral mucosal lesions. As a rule, precancerous lesions are not diagnosed at an early stage since there are no visible clinical signs, and therefore patients do not seek medical attention [8]. An accurate diagnosis requires both basic and additional examination methods. In turn, the conventional methods include traditional inspection, which largely depends on the clinician's experience. Besides the clinical examination, additional techniques are used, namely, fluorescence examination and biopsy [9-11]. Subsequently, optimizing the diagnosis of oral mucosal lesions is the most promising direction in practical healthcare, both in the dental and oncology practice, for early detection and reduction of advanced stages of malignant oral mucosal lesions. Thus, the study confirmed that the development and application of modern approaches are necessary for the early diagnosis of oral mucosal lesions. Purpose. The study aimed to improve the outcome of oral mucosal precancerous and malignant lesion diagnosis by upgrading examination methods.

 Material and methods. The study included 147 patients with oral mucosal lesions, referred to the oncologists of Samara regional clinical oncology centre by the city polyclinics. The patients were divided into two groups according to the examination methods. The control group patients, 63 people, had a conventional examination by a dentist (patient interview, inspection, palpation) and an incisional biopsy by an oncologist. The main group consisted of 84 patients, who, besides conventional dental examination, were evaluated by a new – developed and put into practice – technique with point and index score and subsequent incisional biopsy performed by an oncologist. The studied patients were comparable by gender, age and localization. The study assessed the effectiveness of the new method for the diagnosis of precancerous lesions (PL) and malignant lesions (ML) by matching the Need for Histology Verification Index (NHVI) value equal to 5 points or more and histopathology results.

Results. In the main group, 71 out of 84 patients scored 5 or more according to the new method, and 13 patients scored less than 5. Patients with a low score had a non-surgical treatment, 11 patients reached remission, and two patients were referred to an oncologist for a biopsy, which confirmed oral mucosa PL and ML. The patient complaints in both groups demonstrated that pain and bleeding were more frequent in the control group compared to the main one. The evaluation of clinical examination data revealed more erosions in the control group and nonremovable plaque and hyperplasia in the main group. The incisional biopsy detected more PL and ML in the main group (p = 0.001), and early malignant lesions were in 23% versus 5% in the control group. The new method specificity in oral mucosal PL and ML diagnosis was 55%, sensitivity – 97%, accuracy – 87%, whereas the conventional examination specificity was 28%, sensitivity – 84%, and accuracy – 60%.

Conclusion. The administered improved method for examination of patients with oral mucosal lesions and the compulsory use of autofluorescence examination and risk factor score assessment allowed us to identify PL and ML in 88% and to diagnose more PL and ML at early stages, which explains the need to use this method in the clinical practice for the early diagnosis of lesions.