Clinical implications of the extension of platysmal fibers on the middle and lower face

Background: Despite the area of insertion of the facial portion of the platysma being broad and highly variable, the details of its pattern of extension and morphology are not well described in the medical literature. The aim of this study was to clarify the extension patterns of the platysma on the middle and lower face by topographic examination and detailed dissection. Methods: A detailed dissection was performed in the cheek region of 34 cadaveric specimens. The anatomical aspects of the extent of the platysma were classified according to its area of coverage on the cheek. Results: The location of the posterior fibers of the platysma passing behind the mandibular angle were located 17.1 ± 8.8 mm (mean ± SD) from the mandibular angle. The platysma was classified into patterns (A, B-1, B-2, and C) according to its coverage area: in type A (8.8 percent), areas S1 to S2, M1 to M3, and I1 to I3 were partially covered by the platysma; in type B-1 (58.8 percent), areas M1 to M3 and I1 to I3 were partially covered; in type B-2 (26.5 percent), areas M1 to M2 and I1 to I3 were partially covered; and in type C (5.9 percent), areas I1 to I3 were partially covered. Conclusion: The description of the extent of the facial portion of the platysma presented in this article provides detailed anatomical knowledge regarding the midface, and represents fundamentally important knowledge for surgeons conducting rhytidectomy and other facial operations.