Introduction To Oral Pathology Lecture Notes PDF

Field of Dentistry Lecture : Introduction to oral pathology Introduction and definitions  Etiology of a disease: The multifactorial and/ or predisposing factors that affect the development of a disease or group of diseases. Cause of a disease: The only confirme...

Field of Dentistry Lecture : Introduction to oral pathology Introduction and definitions  Etiology of a disease: The multifactorial and/ or predisposing factors that affect the development of a disease or group of diseases. Cause of a disease: The only confirmed direct cause or factor that gives rise to the disease or abnormal condition. Genetic causes: Alteration in a specific gene where its phenotype results in a specific feature in the body. It is either inherited or acquired (induced). Macule Flat, not-raised, circumscribed, and non-palpable lesion Such as a freckle Papule Palpable solid, elevated, circumscribed lesion, up to 5mm in largest diameter Such as acne Nodule Elevated, solid, and circumscribed lesion, more than 5 mm in diameter Such as fibroma or lipoma Vesicle Elevated, circumscribed, containing fluid (not pus), up to 5 mm in diameter Such as herpes simplex lesions Bulla Elevated, circumscribed, containing fluid (not pus), more than 5 mm in diameter Such as large lesion of thermal burn of skin Adaptive changes Atrophy * Shrinkage in the size of a cell by loss of cell substance * The entire tissue or organ diminishes in size Hypertrophy * The increase of cell size, leading to an increase of the organ size * The hypertrophied organ has no new cells * The cellular enlargement is due to synthesis of more intracellular components  * An increase in the Hyperplasia number of cells in an organ or tissue, which usually increases the organ size or volume * In response to stress or endocrine stimulation Neoplasia and tumor Neoplasia means new cells leading to abnormal mass of tissue, the growth of which is uncontrolled Neoplasia and tumor On the other hand, tumor is a swelling whether due to inflammation, hemorrhage, edema, or neoplasia Microscopic pathologic terms Hyperkeratosis Thickening of the stratum corneum Parakeratosis Retention of the nuclei in the stratum corium Acanthosis Thickening of the prickle cell layer  * Is a reversible change in which one Metaplasia adult cell type (as epithelial or mesenchymal) is replaced by another adult cell type * Such as squamous metaplasia  Dysplasia Is not an adaptive process, but an alteration or variation in size, shape and organization in adult cells Hypoplasia * Is not adaptive in nature * It represents a less severe form of failure of an organ to develop * Hypoplasia implies reduction in the functional mass of the affected organ  Radio-opaque, well-defined. Radiolucent, well-defined. Mixed radiolucent/ radio- opaque: here it appears target-like