The depressor anguli oris (DAO) muscle attaches to the corner of the mouth and the bottom of the mandible (lower jaw), just to the side of the chin. It is one of the muscles which helps make a frown/express disdain. 

Patients with chronic facial palsy from recovered Bell’s Palsy, Ramsay Hunt syndrome, Lyme disease, acoustic neuroma surgery, or trauma, often have too much activity in this muscle on the affected side of their face. This hyperactivity not only pulls down on and restricts the smile, but also can cause tightness, spasm and pain in the cheek and mouth area. 

To remedy this downward pull and smile restriction, we have two options:

1.) Inject Botox into the DAO muscle, which helps relax the downward pull temporarily (lasts about 3-4 months)

2.) Surgically resect the DAO muscle, to permanently relax the downward pull and unlock the smile.

 

The DAO resection procedure itself is performed in the office, and takes about 45 minutes (plan to be at the office for about 90 minutes though, between filling out forms, meeting the team, getting numbed up, etc.). 

When you check in for the procedure, you’ll be taken to one of our exam rooms on the 9th floor, where you’ll be greeted by the surgical team, and marked out with a purple marking pen and given a few numbing injections on the outside of the DAO muscle (chin area) and inside of the mouth (inside the lower lip) which will cause the area to become fully anesthetized.  Next, you’ll be taken into our procedure room, where we’ll get you settled comfortably, and we’ll begin the procedure. 

Because you’ll be numb, you shouldn’t feel anything sharp.  An incision is made inside the lower lip, and fibers of the muscle are identified and removed. 

We then place a few dissolving stitches to close the incision, and you’ll be given a few days of an antibiotic, as well as a small prescription for pain medicine. 

Most patients find that they do just fine on extra strength Tylenol, but we do send you home for a script for something a little stronger just in case. 

You can eat and drink normally after the numbing medication wears off (about 2-3 hours), but avoid excessively hot or spicy foods for 72 hours. 

As you heal, you may develop some swelling on the inside of the mouth over the area where the muscle was removed. This phenomenon is completely normal, and resolves with time--most patients feel like they have some swelling (on the inside of the mouth—not noticeable to anyone but you) and mild tenderness for a few weeks after the procedure, and then that fullness shrinks down to a small little “ridge” inside the mouth. 

After three weeks, patients are encouraged to begin a little gentle scar tissue massage to the area to expedite resolution of the swelling. Please see the postop link below for more specific postop instructions.