"'Your mouth is filthy.' So opens this revolting volume in the Gross Human Body in Action: Augmented Reality series (6 titles), setting a putrid tone for the chapters to follow. While the book contains a few pleasant photos of smiling children and families, it is dominated by closeups of tongues, teeth, and lips, often marred by sores, tartar, or dripping saliva. By delving into disgusting aspects of the mouth, the text fuels an underlying approbation of dental hygiene. In addition to the aforementioned photos, readers will be treated to pictures--three of which produce 3D images when viewed through the free Lerner AR app--and discussions of bacteria, mouth amoebas, taste buds, and cavities. A bullet list of 'Gross Mouth Facts' wraps up this rudimentary, interestingly repugnant health lesson."--Booklist.