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.
A flexible dental plan with no need for referrals. Preferred Provider Organization (PPO)* dental insurance plans provide flexible dental health plan options. 1  Members can visit any licensed dentist without a referral.  The plan provides coverage for preventive, basic and major services.**.