This randomized controlled clinical study will evaluate the effectiveness of the inverted buccal periosteal flap in closing recent post-extraction oroantral communications and compare it with the conventional buccal advancement flap. The study will include 24 patients who develop an oroantral communication measuring 3-6 mm after non-surgical extraction of maxillary posterior teeth. Participants will be randomly allocated into two groups: the test group treated with the inverted buccal periosteal flap, and the control group treated with the buccal advancement flap. The primary outcome will be successful clinical closure of the communication, assessed by absence of oroantral fistula, nasal fluid leakage, and air leakage during the Valsalva test. Secondary outcomes will include postoperative pain, facial edema. Patients will be followed for up to 45 days after surgery.

Oroantral communication is an abnormal connection between the oral cavity and the maxillary sinus, most commonly occurring after extraction of maxillary posterior teeth. If not closed properly, it may lead to oroantral fistula or maxillary sinus complications.

This randomized controlled clinical study will compare the inverted buccal periosteal flap with the conventional buccal advancement flap for closure of recent post-extraction oroantral communications. The study will include 24 patients with communications measuring 3-6 mm and diagnosed within 48 hours after non-surgical extraction.

Participants will be randomly divided into two groups. In the test group, closure will be performed using the inverted buccal periosteal flap, where the periosteal layer is dissected, inverted over the defect, and sutured to the palatal tissue without tension. In the control group, closure will be performed using the buccal advancement flap, where a buccal mucoperiosteal flap is advanced palatally and sutured to cover the communication.

Inclusion Criteria:

1. Presence of an oroantral communication (OAC) with a diameter between 3-7 mm.
2. Communication resulting from extraction of posterior maxillary teeth (first molar, second molar, third molar, or second premolar).
3. Recent perforation occurring no more than 48 hours prior to surgical intervention.

Exclusion Criteria:

1. Presence of foreign bodies or residual tooth fragments within the maxillary sinus.
2. Presence of systemic diseases that could impair wound healing (e.g., uncontrolled diabetes, immunosuppression).
3. History of maxillary sinusitis prior to the perforation.
4. Presence of periapical lesions or cysts at the extraction site.
5. Smokers.