Abstract
<jats:p>The aim of the study. To conduct a pathological study of changes in the maxillary sinus mucosa in cases of oroantral communication following tooth extraction, assessing the relationship between morphological features and clinical manifestations. Additionally, the study aims to analyze the histochemical characteristics of inflammation, including the distribution of mucopolysaccharides, RNA, and mast cells, to understand the mechanisms underlying the chronicity of the process and support therapeutic approaches. Materials and Methods. A retrospective study of 196 patients with perforation of the maxillary sinus floor was conducted. Patients were divided into groups: 1st (mucosal thickening, n = 42; subgroups A, n = 14, B, n = 28), 2nd (polypoid changes, n = 85; A, n = 25, B, n = 60), control (n = 69). Methods: clinical examination, maxillary sinusography with iodolipol, surgical interventions, pathohistological examination (staining with hematoxylin and eosin, Mallory staining, toluidine blue, etc.), histochemical analysis (mucopolysaccharides, RNA, mast cells). Statistical analysis: Student's t-test, χ²-test, Pearson correlation (p < 0.05, SPSS v.25.0). Results. In group 1, limited changes (subgroup A) were characterized by moderate epithelial thickening, stromal edema and minimal infiltration; widespread (subgroup B) – by epithelial metaplasia, pronounced leukocyte infiltration and fibrosis. In group 2, limited polyps (subgroup A) were associated with epithelial crypts and edema; Disseminated (subgroup B) – metaplasia, cavernous vessels, and collagen production. Histochemical analysis revealed accumulation of neutral and acidic mucopolysaccharides, increased RNA and mast cells, correlating with inflammation (r = 0.45–0.85, p<0.01). Spontaneous healing of perforation occurred in 7,1 % of cases; surgical intervention occurred in 92,9 %. Conclusion. Mucosal changes range from localized thickening to diffuse polyposis with progression to fibrosis and metaplasia, supported by chronic inflammation. Histochemical markers (mast cells, mucopolysaccharides) indicate a "vicious cycle" of secretion and reinfection. Early surgical treatment is critical to prevent complications. The results are consistent with the literature and justify a multidisciplinary approach.</jats:p>