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.
1 Learn more about DHMOs. 2  PPO Dental Insurance Plans: Another type of managed care plan is called a preferred provider organization (PPO). 3  Consumers with PPOs select a dentist from a network of preferred dental providers who have agreed to provide dental care to members at reduced rates.