The GI, or digestive, tract extends from mouth to anus (see the image below). The division of the GI tract into upper and lower is a matter of some confusion and debate.
Dental PPO insurance plans, also known as dental preferred provider organizations or DPPOs, are a popular dental insurance option due to their flexibility in allowing insured members to choose dentists and dental specialists.
Preferred Provider Organization â PPO. What is a 'Preferred Provider Organization â PPO'. A preferred provider organization (PPO) is a type of health insurance arrangement that allows plan participants relative freedom to choose the doctors and hospitals they want to visit.