Most people know that smoking can leave yellow or brown marks on teeth. That visible change is real, but it is only the surface of a much larger oral-health picture. Tobacco smoke and nicotine affect the tissues that hold teeth in place, the mouth’s ability to heal, saliva flow, taste and smell, and the way the immune system responds to bacteria. Vaping and other nicotine products can create some related concerns as well, even when they do not produce the same smoke exposure. Oral health is closely tied to everyday…