Defining the Facial extend of the Platysma Muscle

A Review of 71 Consecutive Face-lifts

Anil R. Shah, MD; David Rosenberg, MD

Objective: To delineate the superior (facial) extent of the platysma muscle.

Methods: A total of 142 facial halves were examined from 71 consecutive deep-plane rhytidectomies performed over a period of 3 months. The platysma muscle was identi­fied and isolated during the procedure. The superior ex­tent of the platysma was measured along the line cre­ated by the angle of the mandible to the malar eminence, also known as the malar mandibular line.

Results: On average, the platysma extended 3.98 cm along the malar mandibular line, superiorly from the in­ferior border of the mandible. The platysma was located 3.09 cm inferiorly from the malar eminence along the ma­lar mandibular line. On average, the platysma muscle oc­cupied 56% of the malar mandibular line.

Conclusion: The platysma muscle may have a more sig­nificant facial extension than previously described.
Arch Facial Plast Surg. 2009;11(6):405-408

DESPITE THE MYRIAD OF face-lift techniques avail­able, few surgeons who perform face-lifts would question the role that the platysma muscle plays in rejuvenation of the aging neck.1 However, the extension of the platysma into the face has not been well described. Many anatomy textbooks depict the platysma muscle with its supe­rior border limited by the inferior edge of the mandible (Figure 1). 2 However, we believe that the platysma muscle has a sig­nificant facial extension onto the face (Figure 2). One of us (D.R.) has devel­oped a technique—a variant of deep­plane rhytidectomy—in which the pla­tysma muscle is isolated within the face and neck. Based on more than 7 years of experience with this technique and more than 1000 patients treated, the platysma muscle has been shown to constitute a critical component in the facial aging pro­cess. To support this theory, we per­formed a prospective anatomic study on 71 consecutive patients undergoing rhytidectomy.

During deep-plane rhytidectomy, a unique anatomic perspective exists when the dissection takes place along the un­dersurface of the platysma muscle (Figure 3 and Figure 4). When the mas­seteric fibers are released and separated, the extent of the platysma muscle can be clearly seen, based on the directional as­pects of the muscle fibers and the often thick nature of the facial platysma. Dur­ing surgery, attenuation of the facial pla­tysma can be seen clearly at the midface along its superior extent.

The platysma muscle is a thin sheet­like muscle that originates on the fascia of the deltoid and pectoral regions and runs superiorly and medially, inserting on the mandible, the skin of the cheek, the com­missure of the mouth, and the orbicu­laris oris muscle. 3 The only bony inser­tion of the muscle lies on the anterior third of the mandible. When the platysma muscle tenses, it lifts the neck out (accen­tuating platysmal bands) and lowers the eyelids and midface (accentuating the ma­lar and nasolabial folds) and the man­dible (making the neck shorter and wider), making it the major muscle responsible for the emotive response of surprise. Clini­cally, the actions created by the platysma clearly demonstrate a significant facial component.
Many of the mentioned findings asso­ciated with platysma muscle activity are seen with natural aging.4 With advancing age, the platysma tends to become thin­ner and less defined. 3 In addition, nor­mal aging will cause the platysma muscle to sag and weaken, which creates un­ which creates unsightly platysmal bands or ptosis of the muscle and un­derlying tissues.

The platysma is the most superficial muscular layer of the face and is innervated by the cervical branch of the facial nerve. Embryologically, the platysma muscle is derived from the more superficially lying platysma fas­cia rather than the deeper-lying sphincter colli, in which the muscles of the face arise.5 Beneath the platysma muscle within the face lies an embryologic glide plane that sepa­rates the platysma muscle, derived from the second bran­chial arch, from the deeper-lying masseter, a derivative of the first branchial arch.

The goal of this study was to measure the superior ex­tent of the facial platysma muscle. The implications and applications of our findings are briefly discussed.

METHODS

Based on more than 7 years of experience and more than 1000 patients in whom this technique has been used, we conducted a prospective study in which the anatomy of the platysma was analyzed in 71 consecutive deep-plane facelifts performed from October 1 through December 31, 2007. Patients included in this study underwent primary, revision, and multiple revision facelifts.

All procedures in this study were performed by one of us (D.R.). The technique used is a unique variant of a deep-plane rhytidectomy, in which the platysma muscle is isolated and iden­tified within the face and neck. To isolate the facial compo­nent of the platysma, a No. 10 blade scalpel is used to dissect the superficial musculoaponeurotic system (SMAS) laterally from the line created by the true zygomatic insertion point to the angle of the mandible. Dissection deep to the platysma muscle occurs approximately 1 cm posterior to the nasolabial fold along the face and 2 cm below the mandible. Oblique fibers of the platysma muscle are clearly seen on the undersurface of the dis­section, distinguishing it from the underlying muscles in the face. The direction of the fibers of the platysma muscle distin­guish it from other underlying muscles along the face.

For our study, the platysma muscle was measured along the line created by the angle of the mandible to the malar eminence, also known as the mandibular malar line (MML), by the same surgeon (D.R.). These landmarks were chosen in part because they were easily palpated and replicable from one patient to another. In addition, the fibers of the pla­tysma muscle tend to parallel this line. The superior extent of the platysma muscle was measured from the inferior bor­der of the angle of the mandible along the MML to the attenuation point of the platysma (Figure 5, line A). An additional measure was taken from the malar eminence to the superior border of the platysma along the MML, termed line B (Figure 5). The distance of the MML was calculated in every patient, because of the normal variance associated with face size.

RESULTS

Overall, 71 consecutive patients underwent deep-plane rhytidectomies in which the platysma muscle was measured. Sixty-four patients were women and 7 were men. Seventeen patients had undergone previous rhytidectomies, whereas 54 underwent primary face-lifts.

For all patients, the average distance of line A, the su­perior extent of the platysma muscle along the MML from the angle of the mandible, was found to be 3.98 cm. The average distance from the malar eminence to the supe­rior border of the platysma muscle along the MML, line B, was 3.09 cm. The platysma muscle occupied 56% of the distance of the MML.

In the 7 male patients in the study, line A averaged 3.65 cm, whereas line B averaged 3.15 cm, occupying 54% of the face. Line A in the 64 female patients averaged 4.12 cm, whereas line B averaged 3.09 cm, occupying 57% of the face. When we compared male and female patients, we found that the distance was greater and that the fa­cial platysma occupied a higher percentage of the face in female patients, although the difference was not sta­tistically significant.

In the 17 patients undergoing revision face-lifts, line A averaged 3.27 cm, whereas line B averaged 3.04 cm, meaning that the platysma occupied 52% of the face. Fifty­four patients underwent primary rhytidectomy, and lines A and B in these patients averaged 4.32 and 3.11 cm, re­spectively, with the platysma occupying 58% of the face. The facial platysma was found to be lower along the MML in patients undergoing revision compared with primary rhytidectomy.

COMMENT

This is, to our knowledge, the first study to formally determine the facial extent of the platysma. The traditional view of the platysma (see Figure 1) depicts a muscle that is mostly cervical in nature. However, our study demonstrates that the platysma muscle has a significant extension onto the face (see Figure 2).

There are several reasons why we believe that the fa­cial component of the platysma has been underappreci­ated. Typically, anatomists use an outside-in approach when studying muscle layers. The intimate relationship between the overlying fascia and fibers of the platysma may obscure this relationship and make it difficult to use this approach. By using a natural embryologic glide plane during the procedure, the undersurface of the platysma muscle can readily be visualized (see Figure 3). In addition, facial rejuvenation has focused specifically on the SMAS. Although the SMAS clearly plays a role in facial rejuvenation, much of the credit given to the SMAS may in fact be owed to the facial platysma.

The SMAS is often considered an anatomic extension of the platysma. The SMAS is a fibrous fatty layer that was described as a distinct facial component in the land­mark study by Mitz and Peyroine.6 We believe that dis­tinguishing the SMAS from the platysma is important for several reasons. First, the face and neck should be thought of as a unified concept rather than separate compo­nents. When the SMAS and platysma are treated as 2 sepa­rate components, we have seen noticeable sagging along the jawline and an unnatural component, creating a vi­sual disharmony along the face. Treating the face and neck as a single unit will allow for a more natural appearance (Figure 6). To keep the platysma muscle as a single unit and not attenuate its lateral fibers, we start the dissec­tion laterally. In addition, in our experience, minimiz­ing the subcutaneous elevation of the flap will lead to fewer postoperative vascular issues.

Other authors studying aspects of facial anatomy have noted the extent of the platysma in the face. Mendelson et al 7 recently described the anatomy of the jowl and noted the platysma muscle overlaying this area. When study­ing the anatomy of the midface, Gassner et al8 also noted that the platysma muscle was present within the face. We found that the platysma muscle was actually lower in the face in patients undergoing revision face-lifts com­pared with patients undergoing primary face-lifts. Deep­plane rhytidectomy techniques were not used for the pre­vious procedure for any of the patients who underwent a revision face-lift. A future study examining the loca­tion of the platysma muscle based on previous tech­niques may provide insight into the differences attrib­uted to various rhytidectomy techniques and their role in repositioning the facial platysma. Because of the low numbers in this study, a definitive conclusion would not be advisable.

Our method of measuring the platysma muscle in a surgical setting should be noted. We wanted a method that could be easily replicated. In addition, the platysma muscle fibers extend across the face at an angle, rather than perpendicular to the Frankfort horizontal line. Clini­cal implications of this study demonstrate that the pla­tysma muscle may change face and neck rejuvenation into a unified concept rather than dividing it into the 2 com­ponents of SMAS and platysma. In conclusion, our study supports the notion that the platysma muscle has a significant facial component. Fur­ther anatomic studies are necessary. The facial platysma muscle may play a larger role in surgical procedures on the aging face than previously thought.

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