Depressor labii inferioris (DLI) excision
The depressor labii inferioris (DLI) muscles move the lower lip downward to expose the bottom teeth during smiling. Often, patients with facial palsy have too much activity in this muscle on the unaffected side of their face. This hyperactivity creates an asymmetry while patients smile, since the unaffected side lower lip moves down but the other side does not. By weakening the healthy DLI muscle, we create a more symmetric smile.
We have two options to weaken the healthy DLI muscle to create a more symmetric smile:
1.) Inject Botox into the healthy-side DLI muscle to weaken it temporarily (lasts about 3-6 months)
2.) Surgically resect the DLI muscle, to provide permanent balance.
Resection of this muscle is very straightforward in the office setting, and there is almost no downside. The entire procedure takes 15-20 minutes, though you should plan to be at the office for a solid hour to hour and half between filling out forms, meeting the team, getting numbed up, etc. After the procedure, you can eat and drink normally after the numbing medication wears off (about 2-3 hours), with care just to avoid very spicy or very hot (temperature) items for the first 72 hours after the procedure. The final effect of the DLI resection can be appreciated after a few weeks. There is no visible scarring, since the incision is located inside the mouth. Occasionally patients experience minor temporary lip numbness, or do not get as much weakening as desired, in which case the procedure can be safely repeated.