Dictionary

black eye Bruising of the eyelid and/or the area around the eye as a result of trauma to the eye. Colloquially known as a shiner.

Black Death See bubonic plague.

BKA Below-the-knee amputation. See amputation.

bitewing X-ray A dental X-ray that depicts how the teeth fit together on one side of the mouth.

bite In dental terms, how well the teeth fit together (occlude) in the mouth.

bisphosphonate A class of drugs used to strengthen bone. Bisphosphonates are used to treat osteoporosis and the bone pain from diseases such as metastatic breast cancer, multiple myeloma, and Paget’s disease. Bone is in a constant state of remodeling, whereby new bone is laid down by cells called osteoblasts, while old bone is removed by…

bisexual 1 An individual who engages in both heterosexual and homosexual sexual relations. Bisexual can also refer to the corresponding lifestyle. 2 In physical biology, bisexual refers to an individual who was born with gonadal tissue of both sexes (that is, both testicular and ovarian tissue). Also known as true hermaphrodite.

birthrate The number of live births divided by the average population, or by the population at midyear. Also known as crude birthrate.

birthmark A discoloration of the skin that may or may not be raised and is present at birth. Most birthmarks are harmless. Occasionally a specific type of birthmark can be a visible marker for a more serious health problem. See also café au lait; port-wine stain.

birth defect Any defect present in a baby at birth. Birth defects involve many different tissues, including the brain, heart, lungs, liver, bones, and intestinal tract. These defects can occur for many reasons, including genetic conditions and toxic exposures of the fetus (for example, to alcohol). All parents are at risk of having a baby…

birth control pill See oral contraceptive.

birth control The practice of exercising some level of control over contraception. Birth control methods are many, and they vary in effectiveness. The most effective method is abstinence from sex, followed by oral, injectible, or implanted contraceptives; barrier methods used consistently and with spermicidal gel; and the basal temperature method, if used carefully and consistently….