Abstract Several topics related to the oral cavity are briefly addressed in this article, from anatomical variations that, when recognized, avoid unnecessary investigations, to diseases that affect exclusively the mouth, mucocutaneous diseases, as well as oral manifestations of systemic diseases. A complete clinical examination comprises the examination of the mouth, and this approach facilitates clinical practice, shortening the path to diagnosis in the outpatient clinic as well as with in-hospital patients. The objective of this article is to encourage the examination of the oral cavity as a useful tool in medical practice, helping to recognize diseases in this location. recognized investigations mouth practice inhospital hospital patients location

Abstract Langerhans cell histiocytosis is a rare clonal proliferative disease, characterized by the infiltration of one or multiple organs by histiocytes. Due to the diversity of signs and symptoms, the diagnosis of this disease is often late. The estimated incidence in adults is one to two cases per million, but the disease is probably underdiagnosed in this population. This report presents a case of disseminated Langerhans cell histiocytosis. The authors highlight the most characteristic aspects of this rare and heterogeneous disease, which usually presents as a challenging clinical diagnosis.