Palatal island flap (PIF) is an established technique for closure of oroantral fistulae (OAFs). However, conventional transfer methods commonly require submucosal tunnelling, in which the flap and vascular pedicle are advanced through a confined space between the mucosa and underlying bone. We describe a modified open-route palatal island flap (OR-PIF) technique that incorporates the transfer pathway into the incision design, enables flap elevation from the alveolar side, permits gradual pedicle dissection under direct visualization, and eliminates the need for submucosal tunnelling. The technique was applied in four patients with extraction-related OAFs. One patient with a large bony defect underwent additional reconstruction using a pedicled buccal fat pad flap based on intraoperative judgment. Complete fistula closure was achieved in all patients, with no recurrence, flap necrosis, or major complications during follow-up. This OR-PIF technique allows flap transfer under direct visualization throughout the procedure and may facilitate direct observation and careful intraoperative handling of the greater palatine vascular pedicle. These potential advantages remain theoretical and require confirmation in larger comparative studies.