Definition: The term "platycephalous" is a medical term that refers to a condition where the head of the neck is smaller than the rest of the body. This can occur in various conditions, including sleep apnea, which affects breathing and reduces the amount of oxygen that enters the bloodstream. The name "platycephalous" comes from the Greek word "platys", meaning "flat" or "plain," as well as "cephale", meaning "head". It is often used