Using Botox® in the DAO Muscle

Author

Dr. Stephen Cosentino

The depressor anguli oris (DAO) muscle helps control facial movement around the corners of the mouth. With age, gravity and other factors weaken the muscle, pushing deep fat toward the superficial layers of the chin and turning down the corners of the mouth. This condition is commonly known as “sad smile.”

Targeted botulinum toxin type A injections can temporarily halt this action, reducing the telltale signs of aging in the chin and mouth area. Once all but ignored in favor of injection sites in the upper two-thirds of the face, the depressor anguli oris muscle is now an increasingly popular Botox® injection site.

DAO Muscle Botox Injections: What They Treat

Low-dose Botox injections may temporarily tighten the DAO muscle, counteracting the downward orientation that tends to increase with age. This helps lift the corners of the mouth and lessens the “sad smile” effect.

DAO muscle Botox injections may also reduce the appearance of lines, wrinkles, and dimples in the surrounding areas of the chin. Many providers complement DAO muscle Botox with soft tissue dermal fillers, adding volume and youthfulness to the area.

DAO Muscle Botox Injection Process

The DAO muscle is not a “typical” Botox injection site and has only recently become popular with patients and providers. Care is needed to reduce potential side effects and complications and to ensure effective treatment.

Where to Inject Botox in the DAO Muscle

For best results, the provider should inject Botox on both sides of the mouth. A standard dose is 2 to 4 units per side.

The provider may reduce the risk of complications by injecting into the distal (outer) section of the muscle on each side, close to the motor endplate. To avoid possible lip asymmetry, the provider must not inject Botox into the depressor labii muscle.

How to Inject Botox in the DAO Muscle

The optimal injection depth is in the range of 5 mm, though this can vary from patient to patient. Too-superficial injections will not produce the desired results, and too-deep injections can cause Botox to spread regionally and affect other muscle groups.

Patient Considerations for DAO Muscle Botox Injections

What should patients know before consenting to DAO muscle Botox injections? Here are some common questions and concerns.

Am I a Good Candidate for DAO Muscle Botox Injections?

If you have concerns about age-related downturning of your mouth, you may be a good candidate for DAO muscle Botox injections. During the initial consultation, your provider will examine your lower face as you frown to assess your facial anatomy and determine if Botox is a suitable treatment.

What Are the Risks?

Botox side effects are typically mild and temporary, but the DAO muscle’s location among other important muscle groups does heighten the risk a bit.

Lip asymmetry and “frozen smile” can occur after improperly placed injections, along with “standard” Botox side effects like pain and tenderness, mild swelling, and minor bleeding. For best results, work with a provider who has completed advanced Botox and dermal filler training.

How Long Is the Recovery Time?

You’ll need to take it easy for 24 hours following your procedure but should be able to return to normal activity after that. Listen carefully to your provider’s post-procedure instructions.

How Long Do the Results Last?

DAO muscle Botox injections generally produce visible results for three to six months. The effects may be more durable if dermal fillers are used as well.