The central role of the dentist in the treatment of oncology patients is to care for the patient’s oral cavity before, during, and after radio/chemotherapy. The aim of this research was to determine the knowledge of dental students from five universities in three neighboring countries, Croatia (Split, Rijeka, and Zagreb), Bosnia and Herzegovina (Sarajevo), and Slovenia (Ljubljana), about oncology patients’ dental care. A total of 140 students in their fourth, fifth, and sixth year of dental medicine studies participated in this research. A questionnaire with 36 specific questions was designed for this research and included questions about dental care of oncologic patients before, during, and after the oncology therapy. Most students are familiar with the incidence and most common type of head and neck tumors, while knowledge about tumor treatment and the side-effects of radiation therapy and/or chemotherapy is weak. Students did not show satisfactory knowledge about osteoradionecrosis, which is the most serious side-effect of radiotherapy; therefore, the emphasis on additional education should be greatest in this area. Teaching staff should be aware of lack of student knowledge and try to offer more information and practice in providing dental care for oncology patients.

Clinical signs and symptoms of COVID-19 varied from asymptomatic forms to severe, life-threatening conditions that required treatment in intensive care units. These severe forms of illness are connected with a hypercoagulable state due to excessive inflammation, hypoxia, immobilisation, and altered angiotensin-converting enzyme 2 (ACE-2). In total, 17 COVID-19 positive patients were diagnosed with peripheral arterial thrombosis (AT), 13 of them had COVID-19 pneumonia. Laboratory findings in patients with X-ray confirmed pneumonia showed a four times higher neutrophil-to-lymphocyte ratio (NLR), C-reactive protein (CRP) and three times higher lactate dehydrogenase level (LDH) than patients without confirmed pneumonia. Patients with pneumonia had significantly more bilateral occlusions of the lower extremities and a significantly higher percentage with complete occlusion of the arteries than patients without pneumonia. The rate of limb loss was 35.3%. They were all from the group with COVID-19 pneumonia. Ten out of thirteen patients with pneumonia died due to acute respiratory distress syndrome (ARDS). All patients without pneumonia were discharged from the hospital. The aim of this retrospective study was to report the incidence of arterial thrombosis of lower extremities and their complications in the acute phase of the infection among COVID-19 patients admitted to the hospital for treatment.