Dictionary

perineum The area between the anus and the scrotum in the male and between the anus and the vulva in the female. See also episiotomy.

periodontal Having to do with the gums and supporting structures of the teeth.

periodontal disease A bacterial infection that destroys the attachment fibers and supporting bones that hold the teeth in the mouth. Left untreated, periodontal disease can lead to tooth loss. The main cause of periodontal disease is bacterial plaque, a sticky, colorless film that constantly forms on teeth.

periodontics The branch of dentistry that is concerned with prevention, diagnosis, and treatment of diseases that affect the gums and supporting structures of the teeth.

periodontitis Gum disease with inflammation of the gums. See also periodontal disease.

perioperative Literally, around (the time of) surgery. More specifically, the period of time extending from when the patient goes into the hospital, clinic, or doctor’s office for surgery until the time the patient is discharged home.

periosteal Pertaining to the periosteum.

periosteoma A benign tumor that arises from the periosteum. Also known as periostoma.

periosteum A dense membrane composed of fibrous connective tissue that closely wraps all bone except that of the articulating surfaces in joints, which is covered by a synovial membrane.

periostitis Inflammation of the periosteum.

penis, small See micropenis.

percentile The percentage of individuals in a group who have achieved a certain quantity—such as height, weight, or head circumference—or a developmental milestone. For example, the fiftieth percentile for walking well is 12 months of age.