Dear Dr. Roach: I have venous insufficiency and have a laser procedure by a vein specialist coming up in a couple of weeks. I don't know much about the procedure and wondered if you can expound on it. I am 79 but get told that I look 14 or more years younger. I exercise a lot (aerobics/weights, Pilates), eat well, and usually stay in good health.

I do have some blood vessels starting to show up on one leg. What causes this? What happens to the blood that tries to go through the vein, which doesn't work once the vein is killed by a laser? When the vein is killed, where does the blood go? It's all so confusing.

-- J.W.

Answer: I think of the venous system as streets going through a town. There is at least one main road (sometimes more than one) and lots of side streets. If the main road slows down even a little, cars will drive on the side streets to reach their destination, which can back up the side streets pretty quickly.

In the lower leg, you have a couple of deep major veins, known as the peroneal and tibial veins, which come together to form the popliteal vein. "Venous insufficiency" means that the veins aren't working adequately, usually because the valves that prevent backward flow have failed. So, the pressure in the vein is higher than it ought to be.

This forces the blood to seek other ways back into the heart, including the superficial veins, which can then swell and become painful. Your vein specialist is going to treat those with the laser, preventing blood flow. It's just as if the city put up barriers to close up the side streets.

This is good because the superficial veins won't be swollen, which is unsightly, can lead to ulceration, and may cause discomfort. The blood will simply be forced to go down the "main highway" (the deep peroneal and tibial veins) by the saphenous vein. Other veins deep in the leg will also expand to accommodate additional traffic, so to speak. These large veins do not leak as much and tend not to cause symptoms.

Dear Dr. Roach: I had a molar extracted (the first one, closest to the front), and my periodontist insists on an implant. I don't want it done. My smile is fine, and I don't think my teeth have shifted. Money, pain, recovery - I don't want to go through it.

-- J.D.M.

Answer: It's certainly your decision, but I recommend you do something to replace the molar. It does not have to be an implant; removable partial dentures are another option. But since 90% of your chewing efficiency comes from your first molars, you are likely to notice an improved quality of life from some treatment.

Additional benefits include preventing jawbone loss, which protects the teeth that are nearby. Your teeth may not have shifted yet, but they can in the future due to misalignment, which, in turn, leads to tooth decay.

Contact Dr. Roach at ToYourGoodHealth@med.cornell.edu.