Furcation Grading - Glickman Classification

Grade I

• Incipient.
• Just barely detectable with examination hand instruments.

Grade II

• Early bone loss.
• Examination hand instrument goes partially into the furcation, but not all the way through.
• Furcation may be grade II on both sides of the tooth, but are not connected.

Grade III

• Advanced bone loss.
• Examination hand instrument goes all the way through furcation, to other side of tooth.
• Furcation is through-and-through.

Grade IV

• Through-and-through, plus furcation is clinically visible due to gingival recession.

The AAP definition of a furcation is "The anatomic area of a multirooted tooth where the roots diverge".