An interventional study of Buccal Periosteal Inversion Flap and Buccal Advancement Flap in Acute Oroantral Communication, sponsored by Medical University of Graz. Not yet recruiting at 1 site in Austria. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-10-23.
Sponsored by Medical University of Graz · Not applicable, Interventional, and Treatment
This prospective randomized controlled clinical trial will compare the Buccal Periosteal Inversion Flap (BUPI) with the Buccal Advancement Flap (BAF) for the primary surgical closure of acute oro-antral communications (OAC) following tooth extraction in the posterior maxilla.
The primary objective is to determine whether the BUPI technique results in better preservation of keratinized gingival width compared with the BAF technique three months after surgery.
Secondary outcomes include successful closure rate of OACs, postoperative pain, swelling and bleeding, wound dehiscence or recurrence of the OAC, postoperative sinusitis or infection, reoperation rate, and operating time.
Participants will be randomly allocated in a 1:1 ratio to either BUPI or BAF. Clinical examinations and intraoral scans will be performed before surgery and at follow-up visits after 14 days, one month, and three months.
An OAC is a pathological communication between the oral cavity and the maxillary sinus and occurs most commonly following extraction of posterior maxillary teeth. Surgical closure is indicated to reduce the risk of maxillary sinusitis.
The Buccal Advancement Flap (BAF) is an established technique for primary closure of acute OACs. However, advancement of the buccal soft tissue results often in a reduction of keratinized gingival width and flattening of the oral vestibule, which may negatively affect subsequent prosthetic or implant treatment.
The Buccal Periosteal Inversion Flap (BUPI) is an alternative technique in which the periosteal layer of a buccal mucoperiosteal flap is separated from the overlying mucosa and inverted to cover the OAC. The overlying mucosa can therefore remain largely in its original position.
The study will prospectively compare both surgical techniques in adult participants presenting with an acute OAC following tooth extraction in the posterior maxilla.
After confirmation of eligibility and written informed consent, participants will undergo a baseline intraoral scan of the relevant quadrant and Periodontal Screening and Recording (PSR) of the relevant sextant. Participants will subsequently be randomized in a 1:1 ratio to BUPI or BAF using the Medical University of Graz randomization system.
The primary endpoint is the change in keratinized gingival width between baseline and three months after surgery. Keratinized gingival width will be measured between the mucogingival junction and the midpoint of the alveolar ridge using digital intraoral scans obtained with a 3Shape TRIOS 6 intraoral scanner. Measurements will be performed using 3D Slicer software.
Participants will document postoperative pain, swelling, and bleeding using a visual analog scale ranging from 0 to 10 on the day of surgery and for the subsequent seven postoperative days.
Clinical follow-up examinations will be performed after 14 days, one month, and three months.
Medical University of Graz is the lead sponsor of 470 studies on the registry; 98 are open to participants now.
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Exclusion Criteria:
Participants assigned to this group will undergo surgical closure of the acute oro-antral communication using the Buccal Periosteal Inversion Flap.
Procedure: Buccal Periosteal Inversion Flap
Participants assigned to this group will undergo surgical closure of the acute oro-antral communication using the Buccal Advancement Flap.
Procedure: Buccal Advancement Flap
Following elevation of a trapezoidal buccal mucoperiosteal flap, the periosteum is dissected from the overlying buccal mucosa from apical to coronal. The mobilized periosteal layer is inverted over the oro-antral communication and sutured to the palatal soft tissue to achieve tension-free closure, while the overlying buccal mucosa is largely maintained in its original position.
Also known as: BUPI, Inverted Periosteal Flap, Buccal Periosteal Flap
Following elevation of a trapezoidal buccal mucoperiosteal flap, the periosteum is incised to allow mobilization of the flap. The entire mucoperiosteal flap is advanced over the oro-antral communication to the palatal soft tissue to achieve tension-free primary closure.
Also known as: BAF, Rehrmann Flap, Rehrmann Plastic
Change in Width of Keratinized Gingiva
Change in keratinized gingival width in millimeters between the preoperative baseline assessment and the three-month postoperative assessment. Keratinized gingival width will be measured between the mucogingival junction and the midpoint of the alveolar ridge using digital intraoral scans obtained with a 3Shape TRIOS 6 intraoral scanner and analyzed using 3D Slicer software.
Time frame: Baseline to 3 months after surgery
Successful Closure of the Oro-Antral Communication
Clinical success will be defined as complete closure of the oro-antral communication without persistent communication between the oral cavity and maxillary sinus. The proportion of successfully closed oro-antral communications will be calculated for each study group.
Time frame: 14 days after surgery
Postoperative Pain
Participants will record their daily maximum postoperative pain once daily in the afternoon using a visual analog scale from 0 to 10, where 0 represents no pain and 10 represents very severe pain.
Time frame: Day 0 through postoperative day 7
Postoperative Swelling
Participants will record their daily maximum postoperative swelling once daily in the afternoon using a visual analog scale from 0 to 10, where 0 represents no swelling and 10 represents very severe swelling.
Time frame: Day 0 through postoperative day 7
Postoperative bleeding
Participants will record their daily maximum postoperative bleeding once daily in the afternoon using a visual analog scale from 0 to 10, where 0 represents no postoperative bleeding and 10 represents very severe postoperative bleeding.
Time frame: Day 0 through postoperative day 7
Number of Participants with Postoperative Wound dehiscence
Presence or absence of postoperative separation of the sutured buccal and palatal soft tissues will be clinically assessed 14 days after surgery. Participants will be classified as having wound dehiscence if separation of the wound edges is observed. If wound dehiscence is present, its dimensions will additionally be quantified using the intraoral scan.
Time frame: 14 days after surgery
Dimensions of Postoperative Wound Dehiscence
Among participants with postoperative wound dehiscence, the maximum dimensions of the separation of the sutured buccal and palatal soft tissues will be measured in milimeters using an intraoral scan 14 days after surgerx.
Time frame: 14 days after surgery
Number of Participants with Recurrent or Persistent Oro-Antral Communication
Occurrence of a persistent or recurrent communication between the oral cavity and maxillary sinus during follow-up will be recorded.
Time frame: Up to 3 months after surgery
Number of Participants with Postoperative Sinusitis or Infection
Occurrence of clinically diagnosed postoperative maxillary sinusitis or local infection at the follow-up examination after 14 days will be recorded. Clinical signs and symptoms may include facial pain, pressure sensation, purulent nasal discharge, intraoral purulent drainage, fever, or other clinically relevant signs of infection.
Time frame: 14 days after surgery
Reoperation rate
Percentage of participants in each study group requiring surgical revision because of insufficient closure of the oro-antral communication.
Time frame: 14 days after surgery
Operative time
Duration of the surgical procedure measured from the first surgical incision to completion of the final suture, recorded in minutes and seconds.
Time frame: Intraoperatively on Day 0
Plan to share: Undecided — Not applicable at this time.
Start is estimated for Oct 2026; primary completion for Dec 2027, 14 months later.
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From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is not yet recruiting, as verified in Sep 2026. You cannot join it, but the record below documents what was studied.
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Oroantral Fistula