Background Acute myeloid leukemia belongs to proliferative diseases of the hematopoietic system. It is currently the leading indication for allogeneic hematopoietic stem cell transplantation. This study was designed to determine the most common subjective oral mucosa complaints in patients with acute myeloid leukemia after allogeneic hematopoietic cell transplantation, in relation to the type of conditioning used. Material and Methods Eighty patients diagnosed with acute myeloid leukemia were assigned to two groups depending on the intensity of the conditioning regimen before transplantation: myeloablative and reduced-intensity chemotherapy. The oral symptoms were evaluated based on an authorial questionnaire designed for this analysis. The following oral mucosa subjective complaints were included: pain, paraesthesia, burning mouth sensation, taste disorders, excessive salivation, halitosis, and dryness of the oral mucosa. Results The most commonly reported subjective oral complaint in the examined patients was xerostomia, which was found in 92% of patients during the second visit, followed by spontaneous pain in the mouth (55%), burning (36%), and dysgeusia (20%). It occurred significantly more frequently in patients who underwent myeloablative conditioning. Moreover, it was observed that the frequency of complaints increased considerably after the transplantation, reaching a peak intensity during the second week following the procedure. Conclusions Oral complaints significantly decrease the patients' quality of life during the transplantation and may lead to premature termination of the treatment. As the number of transplantations in patients with acute myeloid leukemia increases, further investigations of oral complaints and symptoms induced by the disease itself and by the therapeutic approaches are required. Key words: Acute myeloid leukemia, oral pathology, xerostomia, myeloablative conditioning, reduced-intensity conditioning.

This study was designed to investigate the frequency and severity of oral mucositis in patients with acute myeloid leukemia after allogeneic hematopoietic cell transplantation, in relation to the type of conditioning used. Eighty patients diagnosed with acute myeloid leukemia were assigned to two groups based on the conditioning regimen used before transplantation. The intensity of oral inflammatory lesions induced by chemotherapy (oral mucositis) was evaluated according to a 5-point scale recommended by World Health Organization. Oral mucosa was investigated in all patients before the transplantation and during two subsequent stages of the post-transplantation procedure in relation to the conditioning regimen used. Mucositis in the oral cavity was observed in the majority of patients (66%) in the first week after transplantation, whereas the largest percentage of patients suffering oral lesions (74%) occurred in the second week after transplantation. A significantly higher percentage of patients with mucositis was observed in the group which underwent myeloablation therapy (74% of MAC and 50% of RIC patients in the first week; 83% of MAC and 53% of RIC patients in the second examination).The severity of mucositis after transplantation was higher in the MAC patients compared to the RIC patients. The highest mean value of the mucositis index was recorded in the second week in the MAC group (1.59). In AML sufferers receiving allo-HSCT, oral mucositis is a significant complication of the transplantation. This condition is more frequent and more severe in patients after treatment with myeloablation therapy.