Blending of the lateral deep slip of the platysma muscle into the buccinator muscle

Purpose The aim of this study was to clarify the prevalence of blending of the lateral deep slip of the platysma into the buccinator, and the morphologic and spatial relationships thereof. Methods The lateral deep slip of the platysma was investigated in 42 specimens of embalmed adult Korean cadavers. Results The lateral deep slip of the platysma was observed in 17 of the 42 specimens (40.5 %). When present, it divided from the deep portion (16 specimens, 38.1 %) or the lateral portion (1 specimen, 2.4 %) of the platysma pars modiolaris. The lateral deep slip passed deep to the facial artery, where it blended into the inferior part of the buccinator. The blending site was located inferolateral to the modiolus. After blending into the buccinator, the fibers of the lateral deep slip coursed longitudinally with the inferior fibers of the buccinator. Conclusion The present description of the topography of the lateral deep slip of the platysma and its relationship with surrounding structures could improve the understanding of the detailed movements of the lower face and the related EMG activities, with the data also being useful when performing facial surgery.