Hypoplasia is underdevelopment or incomplete development of a tissue or organ. Although the term isn't always used precisely, it properly refers to an inadequate or below-normal number of cells. Hypoplasia is similar to aplasia, but less severe. It is the opposite of hyperplasia (too many cells). The name is derived from the Greek: hypo, meaning low, and plasis, which refers to molding or forming. The adjective form is hypoplastic. Hypoplasia can be present in any tissue or organ. It is descript… (More on Hypoplasia)