The importance of the platysma muscle in plastic surgery is well known. During surgery, we have observed that the platysmal fibres do not merely decussate and interlace from each side but that sometimes one side of the muscle overlaps and covers the other side. The aim of this study was to clarify the precise anatomical variations in the decussation and overlapping patterns of the platysma muscle in 70 Korean cadavers. We defined three groups (types I-III) and four patterns (types A-D) according to the length of decussation and the pattern of overlapping, respectively. In 60 specimens (85.7%) we observed decussation and in 10 (14.3%) we did not. In type I there was 0-20 mm of decussating fibres below the mandibular border (43% of specimens). In type II, the decussation of fibres extended over more than 20 mm (43% of specimens). Type III had no decussation (14% of specimens). The proportions of type A (interlacing pattern), type B (right dominant), type C (left dominant) and type D (no decussation) were 41%, 29%, 16% and 14%, respectively. In 45% of the specimens, one side of the platysma covered and overlapped the other side. This is relevant to the removal of the subplatysmal fat in corset platysmaplasty, submental Z-plasty and vertical myectomy of the platysma muscle.
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