People say the eyes are windows to the soul, but if you want to figure out how someone's feeling without gazing lovingly into their eyes, there's a different body part that gives you a quick answer - the mouth. A smile, a frown, pursed lips or an open O-shape are expressions that give away one's emotions. Unfortunately, certain factors can affect the appearance of our mouth. Some people naturally have thin or tight lips, and aging adds wrinkles around the mouth.

That's why many people opt for lip augmentation, not just to correct issues with the lips, but to enhance one's natural appearance. A recent Science Daily release discussed the trend of lip augmentation, and offered a few tips for those interested in the procedure.

Typical signs of aging that prompt a lip augmentation involve a drooping around the mouth, and lip lines that go beyond the red part of the lips.

Usually when doctors talk about lip augmentation, they are referring to a procedure involving the injection of hyaluronic acid to enlarge and plump the lips. These injectable cosmetics fill in depressed areas around the mouth, or they may stimulate collagen production, which naturally plumps the lips. This is caused naturally by the aging process, but can be accelerated by years of smoking or excessive exposure to the sun without protection.

Many plastic surgeons tend to opt for lighter injections the first time around, and then add more in a second treatment if necessary. This is because too much of an injection could lead to an unnatural look, something most cosmetic surgery patients want to avoid.

Patients can speak to a board-certified plastic surgeon to help decide if they are a good candidate for the procedure. According to Science Daily, those who have a large space between the base of their nose and the beginning of their lips may not be the best candidates, as a procedure can create an unflattering "duck bill" look. There are still other options for treating signs of aging around the mouth, such as Botox injections.

Patients can expect their new look to last six months or longer. According to the American Society for Aesthetic Plastic Surgery, lip augmentations offer minimal to no recovery time, meaning most patients can return to their normal activities immediately following the injection, or a day later if sedated. Patients who are curious about plastic surgery but are afraid of permanent commitments may want to consider lip augmentation, since the procedure is temporary.