if you read weston prices book you will see that the ancient civilizations that ate organ meats, including liver, all had fantastic sets of teeth well into old life, with no tooth decay or crooked teeth. as soon as those same cultures adopted modern diet, which includes the eschewing of organ meats, their teeth immediately began deteriorating.
the liver is the most nutrient dense meat in the animals body. therefore you eat less of it.
do you eat any animals products at all? or are you a vegetarian?