Background: The Oro-antral fistulae (OAF) compromises the oral mucosa and the alveolar bone integrity, depleting its capacity to receive dental implants.Purpose: This clinical study aims to assess the clinical outcomes and the radiographic vertical bone gain of an innovative technique that combines the (OAF) closure, bone grafting, and sinus lift. Patients and methods: The study represents a case series conducted on thirteen patients with large (OAF), closed by sliding the buccal advancement flap combined with a distant palatal releasing incision after inverting and elevating the fistulous epithelial tract to set, elevate and conceal the floor of the maxillary sinus from the underlying bone graft. Meanwhile, evaluating the clinical outcomes and justifying a radiographic linear bone height comparison between the sinus floor height preoperatively and three months after. Results: The healing went uneventful, with neither shallowing of the vestibular depth nor obliterating the sinus cavity. The bony sinus floor was admirably elevated, and the grafted defects demonstrated appropriate bone width and height. The mean baseline bone height recorded (9.28 ±2.4 mm) versus ( 17.54 ± 1.6 mm ) for the three months postoperative. The vertical bone gain ranged from (4 to 12.5 mm), with a mean of ( 8.26 ± 2.6 mm), computing a statistically significant linear gain increase ( p < 0.00001). Conclusion: The novel approach provided comprehensive coverage of the oral defect, an appropriate primary elevation of the maxillary sinus with consolidated alveolar graft, cutting short the routine treatment time with the conduction of significant linear bone height gain values.