Preoperative evaluation at rest

Without activation of the brow depressors, this patient has minimal vertical rhytids in her forehead, and she is therefore an excellent candidate for botulinum toxin treatment of her brow depressors ( Figure 50.1 ). For patients with deep, visible rhytids at rest, reasonable expectations should be given and a discussion of the risks, benefits, and alternatives of dermal filler injections for residual vertical rhytids is undertaken. Photographic documentation in the resting and contracting state should be performed.

Preoperative evaluation of dynamic rhytids

With contraction of the brow depressors, this patient exhibits deep vertical furrows or “eleven lines” in the glabella ( Figure 50.2A ). The predominant brow depressors include the midline procerus muscle (yellow), which is located superficial to the paired corrugator supercilii (green) and depressor supercilii muscles (green) ( Figure 50.2B ). The two supercilii muscles have a curvilinear configuration and, with contraction, they act to bring the brows in closer approximation, leading to vertical furrows ( Figure 50.2C ). The vertically oriented procerus muscle causes downward contraction of the brow that leads to transverse furrows across the nasal bridge ( Figure 50.2D ). Note that the corrugator often extends past the mid pupillary line, where it inserts into the superficial dermis. Also, the vertical portion of the orbicularis oculi muscle exerts a downward vector on the brow.