Deep-seated mycoses of the oral cavity and orofacial sphere represent a group of serious fungal infections that can have major repercussions on patients' health, particularly in immunocompromised individuals. This book discusses infections caused by various fungi such as Candida, Aspergillus, mucoral fungi... highlighting the diagnostic and therapeutic challenges they pose due to their ability to mimic other pathologies and their potential to lead to severe complications.The book begins with an overview of the pathogenesis and epidemiology of deep mycoses, highlighting the increase in their incidence due to factors such as HIV/AIDS, anti-cancer treatments, and organ transplants. Varied clinical manifestations, from localized lesions to extensive tissue involvement, are detailed, with descriptions of symptoms which, if not treated promptly, can lead to significant morbidity.