The Langerhans Cell Histiocytosis (LCH) is a disease characterized by the clonal proliferation of Langerhans cells. Patients with this diagnosis can present several manifestations in the oral cavity frequently found are bone lesions and periodontitis. The diagnosis is made with histological and immunohistochemical tests and the main form of treatment is chemotherapy. OBJECTIVE: To evaluate the presence of pathogenic bacteria, bone, dental conditions and manifestations in the oral cavity. METHODS: For this, a study was carried out with patients with LCH, they were submitted to oral swab, simplified periodontal examination (PSR), and panoramic radiography. RESULT: It was found that 36.8% of patients had pathogenic bacteria such as Staphylococcus aureus (10.5%). The PSR showed that 73.6% of the patients had a probing depth of the gingival sulcus of 3 mm or more in the maxilla region and 63.1% in the mandible (moderate periodontitis). The patients presented varied manifestations on the radiograph, such as veiling of the maxillary sinuses (33.3%). CONCLUSION: As it is a disease that affects the oral cavity, it is important that the dentist knows its manifestations and can be diagnosed and treated early in order to reduce mortality, morbidity and promote quality of life for patients.