A retromolar bone graft is a viable procedure for OAF closure. However, harvesting of a retromolar bone can occasionally be combined with removal of the third molar, which may affect acceptance of the procedure by patients [44]. When compared to chin bone grafts, the significant disadvantage of the retromolar donor area is the confined amount of bone available [45]. The incision is made medial to the external oblique ridge in an anterior direction and terminated in the first molar area to avoid interference with the mental nerve branches. A mucoperiosteal flap is elevated, and the exposed bone area is evaluated in consideration of the amount of bone needed at the defect site. A microreciprocating saw is used to make the osteotomies. The bone block is carefully lifted to ensure that the inferior alveolar nerve is not trapped within the graft. Osseous irregularities are trimmed with chisels or by using a large bur. The flap is repositioned and sutured [45].

Zygomatic bone is a suitable donor site for OAF closure. The technique is indicated when a modest amount of bone is needed [46]. In this procedure, an incision is made through the alveolar mucosa about 5 mm above the mucogingival junction, starting between the first and second molars, and proceeds anteriorly to the first premolar area. A full-thickness flap is raised with a periosteal elevator. The dissection extends to the inferior aspect of the infraorbital nerve and around the inferior half of the body of the zygoma. The lateral border of the maxillary sinus is visualized, and the inferior border of the orbital rim is palpated. Bone harvesting is started just above the inferior border of the zygomatic rim and lateral from the maxillary sinus. The incision is closed with running or interrupted resorbable sutures [46].

This method offers the advantage of proximity of the donor area to the recipient area, which minimizes surgical time and patient discomfort [46]. Moreover, surgical postoperative complications after zygomatic bone harvesting are minimal.