Belt buckle ectropion: a distinct mechanism of lower eyelid malposition after Mohs reconstruction

Belt buckle ectropion is a newly recognized mechanism of lower eyelid malposition following Mohs reconstruction. Unlike cicatricial ectropion caused by vertical skin shortage, this variant results from horizontal flap tension acting on a lax tarsus. We retrospectively reviewed three patients who developed postoperative ectropion following subciliary Mohs reconstruction without lid margin involvement. Mechanism, management, and outcomes were analyzed. In all cases, the ectropion resulted from horizontal anterior lamellar tension producing anterior tarsal tilt, confirmed by a negative forced traction test. One case resolved spontaneously, and two required lateral tarsal strip procedures, both yielding successful anatomic and functional outcomes. Belt buckle ectropion represents a distinct post-reconstructive malposition mechanism, correctable with horizontal tarsal tightening rather than skin grafting. Recognition of this pattern may prevent misclassification as cicatricial ectropion and guide appropriate surgical management.