This textbook gives a comprehensive overview of oral histology and oral histopathology. It discusses the microscopic features of normal structures and the cellular changes that occur during the disease processes. Essential knowledge is provided on clinically diagnosed and biopsied samples of lesions and the mechanism involved in the pathological process. The book is divided into three parts: Part one, Oral Histology, serves as a foundation and explains the structure and development of different oral tissues. Part two, Oral Histopathology, presents a classification of diseases and discusses salient microscopic features. Part three, Investigative Oral Pathology, is designed to inform students and clinicians of the methodologies available and used to diagnose oral diseases microscopically. The book and its combined approach to oral histology and histopathology are useful for students and clinicians working in oral pathology, oral surgery, special needs dentistry, and oral health therapy. It also meets the needs of preclinical and clinical dentistry students.