Treatment of microstomia, whether congenital or acquired, has long challenged the ingenuity of surgeons. In all instances, the challenge remains the ability to preserve function and provide and maintain reasonable aesthetics. The following case report presents 2 different cases of surgical correction of microstomia, resulting from flap reconstructions after perioral tumor surgery. We developed a technique that uses pericommissural mucomuscular advancement flap, "a simple fishtail flap," and used this to correct deformed oral commissures in an attempt to elongate the oral aperture in a functional and aesthetically acceptable manner without recurrence. Results have shown that, with the use of our fishtail design, we can restore the unique architecture of the oral commissure with the postoperative intercommissural distance improved by more than 10 mm and the interincisal width enlarged by approximately 5 mm. Our solution was functional and aesthetically acceptable, as well as simpler and cheaper, in comparison with the traditional surgical methods that are usually expensive, complex, and less practical. We believe that, in cases in which either the contracture is mild or a commissurotomy can be expected to increase the width and the general size of the oral aperture, this relatively conservative technique, if judiciously used, can be performed with ease and safety with good results.