Môczáir [14] described closing alveolar fistulas by the buccal sliding flap, shifting the flap one tooth distally. This technique produces only a negligible change in the depth of the buccal vestibule. A drawback of this approach is that it requires a large amount of dentogingival detachment in order to facilitate the shift, which may result in gingival recession and periodontal disease.

The first description of a technique for closing oroantral fistula using a full-thickness palatal flap based on greater palatine artery dates back to Ashley [15]. Advantages of the palatal flap include high vascularity, generous thickness, and quality of tissue. Moreover, this flap is more resilient, less prone to infection, very resistant to lacerations, and does not lead to lowering of the vestibule. However, the most significant disadvantages are flap necrosis [15], exposed bony surface, pain, and development of surface irregularities as a result of secondary epithelialization post operatively [2]. In 1980, Ehrl employed this technique with wide fistulas of 1 cm in diameter [16]. The technique consists of excising the epithelium from its edges and incising the palatal fibro-mucosa so as to create a flap with a posterior base, supplied by the greater palatine artery. The anterior extension of the flap must be wide enough to exceed the diameter of the bony defect and long enough to allow lateral rotation. Tension-free suturing should be performed [8].

The palatal flap has different forms that can be classified by thickness, namely, mucoperiosteal, or by the direction of movement, namely, straight advancement flap, rotation advancement flap, hinged flap, pedicled island flap, anteriorly based flap, submucosal connective tissue pedicle flap, and submucosal island flap.

The palatal mucoperiosteal rotation flap is particularly recommended for the late repair of oroantral fistula [8]. The base of the flap should be broad enough to cover the defect. A full-thickness palatal flap is typically performed lateral to vascular supply and 3 mm apical to the marginal gingiva of the teeth. The mucoperiosteal flap is raised from the anterior to posterior, rotated, and sutured to secure a tension-free closure of the fistula. [8]. With this technique, kinking formation at the rotation point and the base of the flap may compromise the vascular supply [8]. The most important advantages of the technique are rich vascularization, excellent thickness, and easy accessibility.