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.
There are many different types of dental insurance plans, PPOs, DMOs, Medicaid, Union dental plans, and discount dental plans, each having different rules and restrictions on coverage for braces (or Invisalign) and sorting out these differences can be a daunting task. PPO Insurance Plans.