UCSD School of Medicine: Hugh Greenway’s Annual Superficial Anatomy and Cutaneous Surgery

SAN DIEGO – A chief goal during cutaneous surgery in the facial region should be to avoid disturbing or crossing contour lines such as the alar fold, the junction of the eyebrow and forehead, and the eyelid margin, according to Dr. Jenny Kim.

"Alterations in these aesthetic lines will have a profound impact on an individual’s appearance," Dr. Kim said at the meeting sponsored by the University of California, San Diego School of Medicine and the Scripps Clinic. "Functional complications may also result from crossing these lines."

If the defect involves one or more cosmetic units, such as the cheek and nose, "repair each unit separately," advised Dr. Kim, associate professor of medicine and dermatology at the University of California, Los Angeles. "This allows for incisions to be hidden along contour lines and will provide you with a better aesthetic appearance."

She also recommends marking contour lines prior to challenging repairs, such as those in the vermilion border of the lip or in the nasolabial fold.

Skin tension lines, she said, follow the direction of the greatest intrinsic tension in the skin. Also known as maximal skin tension lines, relaxed skin tension lines, and Langer’s lines, skin tension lines "are less well defined compared with contour lines, and incisions placed parallel to these lines heal with a finer, more cosmetically pleasing scar," Dr. Kim said.

Unlike contour lines, skin tension lines vary widely among individuals due to various intrinsic and extrinsic factors "One of the most important intrinsic factors is the collagen in our dermis," she said. "Type I and type III collagen provide 70%-80% of wound volume in the dermis as well as tensile properties of the skin. It resists extensibility under tension and elongates with prolonged tension."

On the other hand, she continued, elastic tissue "will easily be extensible under minimal tension. It has the capacity to resume its original shape after tension is released. Elastic fibers maintain static tension of the skin and provide tensile strength."

Elastic tissue has an increased tension vector parallel to skin tension lines and a decreased tension vector perpendicular to skin tension lines. "These are some of the reasons why you want your wound to be parallel to your skin tension lines," said Dr. Kim, who is also a codirector of the medical school’s Procedural Dermatology Fellowship.

Extrinsic factors that play a role in skin tension lines include the muscles of facial expression, sun damage, aging, and smoking. Aging, for example, leads to fragmentation and loss of elastic fiber, "which is why there’s more variability in skin tension lines as you age," she said.

In order to best determine skin tension lines prior to surgery, have the patient sit upright. "This is because the lines can appear different when a person is lying down versus sitting due to gravity," Dr. Kim said. "Creases and folds secondary to muscle movement can be determined by having patients move facial muscles."

She makes it a point to mark skin tension lines before using anesthesia, "as the swelling from anesthesia makes these lines visible and a patient may not be able to contract muscles later. Draw in the skin tension lines before beginning the surgery. You want to make sure that you maintain function [of the lines], especially around the eyes and the mouth. Evaluate each patient individually, because there are always exceptions to our rules."

Dr. Kim said that she had no relevant financial conflicts to disclose.

SAN DIEGO – A chief goal during cutaneous surgery in the facial region should be to avoid disturbing or crossing contour lines such as the alar fold, the junction of the eyebrow and forehead, and the eyelid margin, according to Dr. Jenny Kim.

"Alterations in these aesthetic lines will have a profound impact on an individual’s appearance," Dr. Kim said at the meeting sponsored by the University of California, San Diego School of Medicine and the Scripps Clinic. "Functional complications may also result from crossing these lines."

If the defect involves one or more cosmetic units, such as the cheek and nose, "repair each unit separately," advised Dr. Kim, associate professor of medicine and dermatology at the University of California, Los Angeles. "This allows for incisions to be hidden along contour lines and will provide you with a better aesthetic appearance."

She also recommends marking contour lines prior to challenging repairs, such as those in the vermilion border of the lip or in the nasolabial fold.

Skin tension lines, she said, follow the direction of the greatest intrinsic tension in the skin. Also known as maximal skin tension lines, relaxed skin tension lines, and Langer’s lines, skin tension lines "are less well defined compared with contour lines, and incisions placed parallel to these lines heal with a finer, more cosmetically pleasing scar," Dr. Kim said.

Unlike contour lines, skin tension lines vary widely among individuals due to various intrinsic and extrinsic factors "One of the most important intrinsic factors is the collagen in our dermis," she said. "Type I and type III collagen provide 70%-80% of wound volume in the dermis as well as tensile properties of the skin. It resists extensibility under tension and elongates with prolonged tension."

On the other hand, she continued, elastic tissue "will easily be extensible under minimal tension. It has the capacity to resume its original shape after tension is released. Elastic fibers maintain static tension of the skin and provide tensile strength."

Elastic tissue has an increased tension vector parallel to skin tension lines and a decreased tension vector perpendicular to skin tension lines. "These are some of the reasons why you want your wound to be parallel to your skin tension lines," said Dr. Kim, who is also a codirector of the medical school’s Procedural Dermatology Fellowship.

Extrinsic factors that play a role in skin tension lines include the muscles of facial expression, sun damage, aging, and smoking. Aging, for example, leads to fragmentation and loss of elastic fiber, "which is why there’s more variability in skin tension lines as you age," she said.

In order to best determine skin tension lines prior to surgery, have the patient sit upright. "This is because the lines can appear different when a person is lying down versus sitting due to gravity," Dr. Kim said. "Creases and folds secondary to muscle movement can be determined by having patients move facial muscles."

She makes it a point to mark skin tension lines before using anesthesia, "as the swelling from anesthesia makes these lines visible and a patient may not be able to contract muscles later. Draw in the skin tension lines before beginning the surgery. You want to make sure that you maintain function [of the lines], especially around the eyes and the mouth. Evaluate each patient individually, because there are always exceptions to our rules."

Dr. Kim said that she had no relevant financial conflicts to disclose.

SAN DIEGO – A chief goal during cutaneous surgery in the facial region should be to avoid disturbing or crossing contour lines such as the alar fold, the junction of the eyebrow and forehead, and the eyelid margin, according to Dr. Jenny Kim.

"Alterations in these aesthetic lines will have a profound impact on an individual’s appearance," Dr. Kim said at the meeting sponsored by the University of California, San Diego School of Medicine and the Scripps Clinic. "Functional complications may also result from crossing these lines."

If the defect involves one or more cosmetic units, such as the cheek and nose, "repair each unit separately," advised Dr. Kim, associate professor of medicine and dermatology at the University of California, Los Angeles. "This allows for incisions to be hidden along contour lines and will provide you with a better aesthetic appearance."

She also recommends marking contour lines prior to challenging repairs, such as those in the vermilion border of the lip or in the nasolabial fold.

Skin tension lines, she said, follow the direction of the greatest intrinsic tension in the skin. Also known as maximal skin tension lines, relaxed skin tension lines, and Langer’s lines, skin tension lines "are less well defined compared with contour lines, and incisions placed parallel to these lines heal with a finer, more cosmetically pleasing scar," Dr. Kim said.

Unlike contour lines, skin tension lines vary widely among individuals due to various intrinsic and extrinsic factors "One of the most important intrinsic factors is the collagen in our dermis," she said. "Type I and type III collagen provide 70%-80% of wound volume in the dermis as well as tensile properties of the skin. It resists extensibility under tension and elongates with prolonged tension."

On the other hand, she continued, elastic tissue "will easily be extensible under minimal tension. It has the capacity to resume its original shape after tension is released. Elastic fibers maintain static tension of the skin and provide tensile strength."

Elastic tissue has an increased tension vector parallel to skin tension lines and a decreased tension vector perpendicular to skin tension lines. "These are some of the reasons why you want your wound to be parallel to your skin tension lines," said Dr. Kim, who is also a codirector of the medical school’s Procedural Dermatology Fellowship.

Extrinsic factors that play a role in skin tension lines include the muscles of facial expression, sun damage, aging, and smoking. Aging, for example, leads to fragmentation and loss of elastic fiber, "which is why there’s more variability in skin tension lines as you age," she said.

In order to best determine skin tension lines prior to surgery, have the patient sit upright. "This is because the lines can appear different when a person is lying down versus sitting due to gravity," Dr. Kim said. "Creases and folds secondary to muscle movement can be determined by having patients move facial muscles."

She makes it a point to mark skin tension lines before using anesthesia, "as the swelling from anesthesia makes these lines visible and a patient may not be able to contract muscles later. Draw in the skin tension lines before beginning the surgery. You want to make sure that you maintain function [of the lines], especially around the eyes and the mouth. Evaluate each patient individually, because there are always exceptions to our rules."

Dr. Kim said that she had no relevant financial conflicts to disclose.