This article is from the WSSF 2017 AFRMA Rat & Mouse Tales news-magazine.

Did You Know?  The mandible incisors of rats and mice (lower front teeth) are mobile and loosely rooted in the lower jaw. They are naturally ⅔ to ¾ longer than the top maxillary incisors.

A Champagne Satin (with white teeth, see It’s In The Teeth WSSF 2011) showing the longer mandible incisors. Mouse owned and bred by Karen Robbins, Karen’s Kritters. Photo ©2010 Craig Robbins.

From Veterinary Nursing of Exotic Pets by Simon J. Girling, John Wiley & Sons, 2013, ISBN 978-0-470-65917-5.