About what percent of lower front teeth bone loss is there before a tooth becomes loose and requires extraction?

Depends-which teeth?: Think of the root as shaped like an ice cream cone. Hold the cone with two hands all the way up to the scoop. Now take away the top hand. How much control remains? Same thing in the mouth, I have seen front tooth cases with almost 90% vertical bone loss survive. Multi- rooted/molar teeth? Poorer prognosis. Ask your dentist for a qualified referral if s/he not able to provide treatment.

Dental eval needed : This will vary with each individual. Some of the other factors involved are related to the bite, biting forces, grinding, diet, oral hygiene, smoking, and habits. Some patients can have advanced bone loss and the teeth can still be solid and can remain for a long time. Brush, floss, have your teeth cleaned at the interval recommended by your dentist or periodontist.

60%: It also depends on the health of th complete support mechanism in the gum tissue.

Varies: Depends on the amount and position of the remaining teeth and the biting forces placed on the tooth. Also, somewhat on the strength of your bone. On average, once you have lost 30 -40 % of the bone the teeth are noticeably looser and often painful when biting. See the periodontist -- the expert in gums / bone support. Good luck.