Concepts in eyelid biomechanics with clinical implications.

The inner canthal orbicularis drives spontaneous blinking of the eyelids and is richly innervated by a branching network of twigs based largely on the buccal branch of the facial nerve. This segment of the orbicularis is relatively resistant to denervation from subciliary incisional approaches. Combined with proper eyelid tension, contraction of this segment of orbicularis results in the normal physiologic blink mechanism. The authors discuss how to achieve proper eyelid tension and position intraoperatively during the treatment of patients with a range of orbital morphologies.