Ph.D. Gruzdeva A. A.

State Establishment "Dnepropetrovsk Medical Academy 

Ministry of Health of Ukraine"

PATHOLOGICAL CHANGES OF THE ORAL MUCOSA AND PERIODONTAL TISSUES BY THE WORKERS OF MINING INDUSTRY

Production conditions of iron ore industry promote occurrence of pathological changes of the oral mucosa and periodontal diseases.

The prevalence of lesions of oral tissues in workers related to exposure to hazardous occupational factors is significantly higher than those without contact with a professional harm.

On the enterprises of the mining industry in Dnepropetrovsk region under unfavorable and hazardous working conditions employs about 65, 9% of all industry workers [7, 8].

The use of personal protection against harmful factors of production, introduction of new technological processes have reduced professional diseases among miners. However, it’s level remains high.

With 7 - 8 years of working experience defeats of the oral mucosa and periodontium are 80 – 90 %. Bots M. I. in a survey of underground miners has revealed periodontal disease in 86 % of workers [9]. Depth of periodontal lesions increases with the length of working time. At the same depth and activity of the pathological process the parameters of microcirculation among the workers were significantly lower than in the control group: Vacuum test (named after Kulazhenko W. I.) 9,5 ± 0,1 vs. 26,4 ± 0,3.

          Leukoplakia  is the mouth's reaction to chronic irritation of the mucous membranes of the mouth.

       Violation of maturation of the epithelium of the oral mucosa is the leading element of pathogenesis of  leukoplakia. Exfoliative cytology is a noninvasive procedure, which helped in identifying the cellular changes. The study revealed a subclinical phase of OHL, where the cellular changes were seen even before the appearance of the clinical lesion [2]

       The degree of maturity of the epithelium (maturation index) is determined by the balance of epithelial cells. In the epithelium of the mucous membranes of the mouth are allocated: basal, parabasal, intermediate and superficial cells, and in the stratum areas - horny scales.

       The basal cells can be in the smear with deep inflammation of the epithelium by its injury. The presence of parabasal cells shows sharply expressed atrophy. A sign of maturation of the epithelium is the predominance of intermediate cells in the smear. In not cornified sites of the oral mucosa to the maximum level of maturation of the epithelium corresponds the appearance of the surface cells, and in the cornified - horny scales.

       Maturation index (the ratio of parabasal / intermediate / surface / horny scales) assess the degree of differentiation of epithelial maturation completeness. As a normal for the not cornified epithelium is considered to be ratio 0 / 96 / 2,5 / 1,5; for cornified epithelium – 0 / 60 / 8 / 32 [6]. Oral exfoliative cytology has 100% specificity [3].

       Although it is considered a potentially malignant disorder the overall malignant progression of oral leukoplakia is of the order of 5% and even more. Nowadays there are no currently accepted markers to distinguish those that may progress to cancer from those that may not [5].

       Routine exfoliative cytology may be a reliable, noninvasive, and inexpensive technique for the diagnosis of hairy leukoplakia [1]. Oral exfoliative cytology has 100% specificity [3].

      The aim of our study was to determine the degree of maturity of the epithelium of the oral mucosa in different forms of leukoplakia and examine the state of gums among workers of iron ore industry with a help of electron-microscopic method and structure of the bone tissue with a help of densitometry method.

Materials and methods. We conducted a clinical and laboratory study of 58 patients with leukoplakia of the oral mucosa. In our study we used the classification of the oral mucosa by Danilevsky N. F., Urbanowich L. I., 1979. The flat form of  leukoplakia was diagnosed in 34 patients (58.62%), rising leukoplakia - in 16 (27.58%), verrucous leukoplakia - in 5 (8.26%) and erosive form - in 3 (5.17%) .

       For the manufacture of the cytological preparations the fence of the lesion was performed in several ways: direct imprint, impression smears or scraping. Preparations were fixed in a mixture of Nikiforov. Coloring was performed by Papanikolau. In smears we had examined the ratio of epithelial cells.

The material for the study were the fragments of gingival papillae of 24 workers in the age of 30 – 60 years, with working experience of 5 – 20 years, which have been taken in the course of surgery for medical reasons. Ultrathin sections were obtained on a ultramicrotome UMPT-7 and contrasted by Reynolds, also they were stained with uranyl acetate and lead citrate. They were viewed in the electron microscope TEM-100.

Results and its discussion. In patients with flat form of  leukoplakia among the epithelial cells in the smear prevailed horny scales (51,5%) and superficial cells (31%). The content of intermediate cells was reduced to 17.5%. All this can be interpreted as a violation of the maturation of the epithelium, as hyperkeratosis and chronic inflammation.

       In patients with rising leukoplakia the breach of epithelial differentiation was aggravated: the ratio of parabasal / intermediate / surface / horny scales was 0/25/29/46.

      The analysis of the results of cytological research of patients with warty leukoplakia revealed a severely impaired maturation of the epithelium – so named “left shift”. In this case, in a smear appeared basal (3%) and parabasal (10,5%) cells, were observed phenomena of dyskaryosis, that is reflecting the increasing damaging effect on the oral mucosa.

       The results of cytological research in patients with erosive form of leukoplakia are typical for a significant injury of the epithelium and for the defeat of it with a deep inflammation. In compare with warty form of leukoplakia in smears were found the increasing of basal (4%) and parabasal cells (15,5%).

Significant changes in the gingival epithelium of examined patients were identified. Almost everywhere were the loosening areas of intercellular contacts defined, sometimes it was accompanied by a loss of edge definition of intercellular membranes. In other places, while maintaining the sharpness of the cytoplasmic membrane, intercellular contacts took the form of channels field with an amorphous content of different density, what indicates loosening of the epithelial layer. Almost everywhere, there were areas in which signs of inter- and intracellular edema were detectable. The nuclei of the epithelial cells, in some cases, had a scalloped shape with protrusions or invaginations of  karyoplasm. In the nuclei of the cells, there was a sharp decrease in the chromatin, which condensed on the periphery of  karyoplasm.

Significant changes have taken place in the interior lying tissues. Most microvasculars were paralytic expanded. Endothelial cells appeared swelled with sharp increased cores. In the nuclei of myocytes rapidly reduces the content of chromatin which condensed at the nuclear membrane. In the cytoplasm, there were signs of destruction of organelles (mitochondria). There was swelling of the myofibrils.

It should be noted, that all the examined had the lack of oral hygiene and parodontal tissue destruction intensity was increased with age.

Conclusions. Analysis of data, obtained in electron-microscopic study shows that, while retaining the overall organization of the epithelial layer and underlying structures, there were some changes in the ultrastructure of the individual components of the gum. Changes had mosaic nature and in different areas were expressed in varying degrees. In some zones changes in the ultrastructure showed intercellular and intracellular edema of mainly epithelial cells, in other areas they had the nature of dystrophic and even destructive changes, what indicates the depth of the destruction of the cells ultrastructure.

So, the degree of maturity of the epithelium decreases with worsening of the forms of leukoplakia. Determining of the degree of differentiation of epithelium of the oral mucosa with the use of exfoliative cytology method is the auxiliary diagnostic test for the diagnosis of "leukoplakia" and can be used in combination with other methods of research. The method of exfoliative cytology is characterized by simplicity, security, rapidity of obtaining of results and plays an important role in the diagnosis of different forms of leukoplakia.

REFERENCES

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3.     Sathish Kumar, N. Vezhavendhan, Priya S. Role of Oral Exfoliative Cytology in Oral Leukoplakia and Squamous cell Carcinoma. International Journal of Clinical Dental Science, Vol 2, No 1 (2011)

4.     Ajay Reginald and B. Sivapathasundharam. Oral hairy leukoplakia: An exfoliative cytology study.  Contemp Clin Dent. 2010 Jan-Mar; 1(1): 10–13.

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