Does the optimal layer of the skin include the orbicularis oculi muscle when elevating cheek rotation flap? Naohiro Ishii, Masayoshi Takayama, Shigeki Sakai, Kazuo Kishi Journal of Cutaneous and Aesthetic Surgery 2019 12(2):112-117 Background: The cheek rotation flap is widely used as an optimal technique for lower eyelid reconstruction; however, the elevation layer of the skin including the orbicularis oculi muscle (OOM) remains unresolved. Materials and Methods: Between February 2006 and October 2012, 11 patients who underwent repair of partial-thickness defects of the lower eyelids using the cheek rotation flap were included in this prospective study. We investigated the influence of elevating the layer of skin including the OOM on the incidence of perioperative complications, operation time, long-term postoperative morphology, and function of the lower eyelid. The layer of flap elevation was deep to the OOM in four patients (deep to OOM cases) and superficial to the OOM in seven (superficial to OOM cases). Results: The superficial to OOM cases had a similar incidence of perioperative complications including flap congestion as the deep to OOM cases. However, the superficial to OOM cases required a significantly longer operation time. Furthermore, lid retraction was found in all of the deep to OOM cases and none of the superficial to OOM cases. In addition, the postoperative results in all the superficial to OOM cases showed satisfactory contours of the lower eyelid without revision surgery. However, many of the deep to OOM cases needed revision surgery to improve lid retraction. Conclusion: The cheek rotation flap should be elevated in superficial to the OOM cases because postoperative lid retraction occurred significantly more in the deep to OOM cases than in the superficial to OOM cases, although elaborate dissection may prolong the operation time.