Struggling to open mouth since SMAS lip augmentation, 1.5 years post op - What could be causing this?

Thank you for your question.

What you are describing may be related to the combination of SMAS and scar tissue build-up in the upper lip, following your surgery.

The SMAS layer is generally strong enough to hold tension, but would not usually be as rigid as what you are describing. Scar tissue developed around it may reduce its flexibility.

Removing the SMAS from the upper lip is likely to be difficult. It may however be possible to divide the SMAS implant in one or several areas so that it allows expansion of the mouth but maintains the shape of the lips when relaxed.

It is preferable to discuss this with your surgeon who would knows exactly how they tend to create the tunnel for the lip augmentation.

You may have had some nerve damage, especially with the buccal fat removal so that you cannot pucker your lips or open your mouth as wide. An examination is needed to be certain.