A 67-year-old male patient sought implant rehabilitation for the purposes of restoration of occlusal support and assistance with chewing difficulties. Clinical and radiological examinations revealed that teeth were absent 26–27. The clearance from the alveolar ridge to the opposing teeth was 20 mm (Fig. 1). A CT scan showed that the distance from the reabsorbed ridge to the floor of the maxillary sinus was approximately 26: 6.1 mm and 27: 7.5 mm, and the width of clearance was approximately 8 mm. The alveolar bone defect in this case was the loss of ridge height with normal ridge width, class II according to the Seibert classification [20]. Additionally, septa and a thickened sinus membrane were evident within the maxillary sinus (Fig. 2).

As a preoperative diagnosis, it was determined that the septa and a thickened sinus membrane meant that sinus lift augmentation was difficult, and bone augmentation to the crown side was required, but the morphology of the alveolar ridge had been well maintained. The treatment options included using short implants, but evidence on their long-term outcome was still limited at that time.

It was determined that the best treatment involved segmental osteotomy and placement of an interpositional graft using the bone removed from the ramus of the mandible to restore the posterior maxillary alveolar ridge, prior to placement of dental implants.

The operative procedure was performed after the induction of general anesthesia using a 1/160,000 xylocaine solution with epinephrine 1:100,000. A linear incision was made 3 mm above the mucogingival junction. The mucoperiosteum was detached, and the vertical and horizontal osteotomies were prepared using micro-saws. Chisels were used to finalize the osteotomies and to mobilize the bony segment. Care was taken not to damage the palatal mucosa. The surgery proceed to the removal of a bone graft block (17 × 10 × 4 mm) from the ramus of the left mandible and the adaptation thereof to the recipient site with the cortical portion facing the vestibular side (Fig. 3). The device formed by the mobilized bone segment and the interposed bone graft block was fixed using WY-type microplates and screws (Stryker Japan, Tokyo, Japan). Crushed autologous bone was applied to the region of the graft (Fig. 3). The procedure was finalized using a running stitch for closure with 5-0 nylon catgut.