**2.2 The donor site**

Retromolar/ramus region is the gold standard of this technique. It can provide cortical bone blocks of 3-4 mm thickness, 2–3 cm length, 8-12 mm width (height). In the present case, the left retromolar area was the donor site. Under general anesthesia, administration of IV Augmentin 1 gr, Iv Dexamethasone 20 mg, and local anesthesia with a vasoconstrictor. A full-thickness mucoperiosteal flap was reflected with mid-crestal incision distal to the second premolar. The incision was extended through the retromolar region and the external oblique ridge to the ramus. An anterior release incision was performed at the first premolar and extended to the vestibular depth. This flap exposed the left augmented site (teeth 36 and 37 region), and the donor site of the bone block. In addition, it allowed visualization of the lateral and inferior border of the mandible, the buccal shelf, and the mental neurovascular bundle. The length (posterior–anterior) of the bone block, the width (superior–inferior) were determined and done by three complete osteotomies; posterior, anterior, and inferior (**Figure 2a**), using a micro-Saw (Dentsply Friadent, Mannheim, Germany). The superior (crestal) edge was perforated with small holes by small round bur in a straight hand-piece, those holes determined the thickness of the bone block. The block harvest was completed by a straight osteotome that was tapped along the superior holes. The block was carefully released and removed to avoid injury to inferior alveolar neurovascular bundles, and the donor site was left for spontaneous regeneration.

#### **Figure 2.**

*The donor site and the Wedge preparation. (a) The bone block harvesting from the left retromolar area. (b–f) Multiple splitting of the bone blocks results in multiple small bone wedges. (g–j) Transverse splitting of the harvested bone block, as an additional option to create the bone wedges.*
