Our improved understanding of the pathophysiology of facial lines, wrinkles, and furrows has broadened the treatment options for a variety of facial cosmetic blemishes. The persistence or recurrence of certain facial rhytids after surgery has confirmed the lack of full comprehension of their origin. Glabellar forehead furrows (frown lines) and lateral canthal rhytids (crow's feet) have been the most popular facial lines that have been shown to be mostly the result of regional hyperkinetic muscles, and their eradication may be more suitable, at times, to chemodenervation than to soft-tissue fillers, skin resurfacing, or surgical resection. Aesthetic surgical procedures that have yielded suboptimal results may also occur from failure to recognize other causative factors including hyperkinetic or dynamic musculature, which may contribute to etiology of the visible soft-tissue changes and lack of persistent effect after surgery. Chemodenervation with botulinum toxin A (Botox) has proven to be useful both as a primary treatment for certain facial rhytids and as an adjunctive agent for a variety of facial aesthetic procedures to obtain optimal results.
The logical approach to facial rejuvenation is facilitated when one first (through an assessment and diagnosis of the nature of the pathology) differentiates quantitative from qualitative changes in facial soft tissue. Quantitative and malpositional changes have traditionally required a surgical approach: the excision or repositioning of soft tissue (skin, muscle, and fat). Conversely, qualitative changes may require the fortification of the soft tissue by mechanical, chemo- or laserexfoliation, or augmentation of a particular soft-tissue plane. Most recently, a focus has been directed to prevention with sun protection, skin care, and improved nutrition as well as the realization of other causative risk factors that include hyperfunctional and dynamic components of facial lines.
Hyperdynamic (hyperkinetic, hyperfunctional) or long-term facial muscular animation seems to contribute to the etiology of many undesired facial rhytids and furrows. The presumption that facial lines were the result of, in part, forces generated by local muscular actions was first observed post-mortem on a microanatomic basis by Pierard and Lapiere. 1 Focal denervation of particular facial muscles has been shown to improve overall facial appearance not only by temporarily eliminating rhytids but also by improving malpositional changes of the overlying soft tissue and possibly the results of particular facial aesthetic surgical procedures discussed herein.