Oroantral CommunicationAOCNCT07476664
Acute Oroantral Communication Closure: Resorbable Collagen Membrane vs. Buccal Advancement Flap Outcomes
A study testing Resorbable collagen membrane OAC closure and Buccal advancement flap OAC closure in people with Oroantral Communication and Acute Oroantral Communication, run by Medical University of Silesia at 1 site in Poland.
Trial summary
Oroantral communication (OAC) is an abnormal opening between the oral cavity and the maxillary sinus that may occur after extraction of posterior maxillary teeth. If not treated promptly, it can lead to sinus contamination, chronic infection, and development of an oroantral fistula requiring more complex surgical… Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Oroantral Communication, Acute Oroantral Communication, Oroantral Fistula
- What is being tested?
- Resorbable collagen membrane OAC closure and Buccal advancement flap OAC closure
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 24 participants
- Where
- 1 sitePoland
- Study dates
- 1 May 2021to 1 Dec 2025
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Adults aged 18 years or older
- Acute oroantral communication diagnosed within 24 hours after extraction of a maxillary posterior tooth
- General health status permitting outpatient dental surgery
- Indication for single-tooth extraction in the posterior maxilla
- Systemic conditions not contraindicating minor oral surgery
- Ability and willingness to attend scheduled follow-up visits
- Provision of written informed consent
Who cannot join
- Oroantral communication present for more than 24 hours
- Chronic inflammatory disease of the maxillary sinus
- History of head and neck neoplastic disease or its treatment
- Pregnancy
- Systemic diseases preventing outpatient surgical treatment
- Blood disorders or coagulation abnormalities
Show all 10Show fewer
- Ongoing anticoagulant therapy
- Immunosuppressive therapy
- Age under 18 years
- History of multiple previous surgical procedures in the study area
Trial locations and contacts
1 site in 1 country.
Poland1 site
University Dental Clinic of the Silesian Medical University in Katowice
Bytom
About this study
Oroantral communication (OAC) is an abnormal opening between the oral cavity and the maxillary sinus that may occur after extraction of posterior maxillary teeth. If not treated promptly, it can lead to sinus contamination, chronic infection, and development of an oroantral fistula requiring more complex surgical management. The standard surgical treatment is closure with a buccal advancement flap (Rehrmann technique). However, this method may reduce vestibular depth, displace the mucogingival junction, and decrease the width of keratinized gingiva.
This prospective clinical study compares two surgical approaches for closure of acute OAC diagnosed within 24 hours after tooth extraction: placement of a resorbable collagen membrane beneath the mucosa versus the conventional buccal advancement flap. Clinical and radiographic parameters related to soft tissue architecture, postoperative recovery, and bone healing are evaluated during a 90-day follow-up period.
Read the detailed description
Oroantral communication (OAC) is a pathological connection between the oral cavity and the maxillary sinus most commonly occurring after extraction of posterior maxillary teeth. The close anatomical relationship between the sinus floor and the roots of maxillary molars and premolars increases the risk of perforation of the Schneiderian membrane during dental extraction. If an OAC is not diagnosed and treated promptly, microbial contamination of the sinus may occur, potentially resulting in chronic maxillary sinusitis and epithelialization of the tract with formation of an oroantral fistula. Early closure of acute defects within 24-48 hours is therefore generally recommended.
The buccal advancement flap described by Rehrmann is the most frequently used surgical technique for closure of acute OAC because of its technical simplicity and predictable closure of the defect. Nevertheless, advancement of the buccal mucoperiosteal flap may alter local soft tissue anatomy, including reduction of vestibular depth, displacement of the mucogingival junction, and loss of keratinized gingiva. These anatomical changes may affect oral hygiene and may complicate future prosthetic or implant therapy.
Biomaterial-based techniques that preserve soft tissue architecture represent a potential alternative approach. Resorbable collagen membranes are widely used in guided tissue regeneration and guided bone regeneration due to their biocompatibility, clot stabilization properties, and barrier function. Heterologous collagen membranes, such as Creos Xenoprotect, are designed to integrate with surrounding tissues and gradually resorb without the need for surgical removal. Their use for closure of acute OAC has been described in clinical reports; however, comparative clinical data against conventional flap techniques remain limited.
The present study is designed as a prospective, non-randomized comparative clinical investigation evaluating two surgical methods for closure of acute oroantral communications diagnosed within 24 hours after extraction of posterior maxillary teeth. Adult patients presenting with clinically and radiographically confirmed OAC are screened for eligibility and allocated to treatment according to the predefined clinical protocol.
In the experimental group, closure of the communication is performed using a resorbable heterogeneous collagen membrane (Creos Xenoprotect) placed in a submucosal position to cover the defect. Limited mucoperiosteal elevation is performed as necessary, and the membrane is stabilized using sutures to achieve tension-free closure.
In the control group, closure is performed using the conventional Rehrmann buccal advancement flap. After preparation of the extraction socket, a trapezoidal mucoperiosteal flap with vertical releasing incisions is elevated, mobilized using periosteal releasing incisions, and advanced coronally to achieve primary closure of the defect.
The size of the oroantral communication is measured clinically using a calibrated periodontal probe and confirmed with limited-field cone-beam computed tomography (CBCT). Standardized perioperative management is applied in both groups, including socket debridement, smoothing of bony margins, sinus precautions, and scheduled postoperative follow-up.
- Conditions
- Oroantral Communication, Acute Oroantral Communication, Oroantral Fistula, Post-extraction Maxillary Sinus Communication
- Being tested
- Resorbable collagen membrane OAC closure, Buccal advancement flap OAC closure
- Keywords
- oroantral communication, acute OAC, buccal advancement flap, Rehrmann flap, oral surgery, CBCT bone density, vestibular depth preservation
- Medical subject headings
- Oroantral Fistula
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Resorbable collagen membrane OAC closureProcedure or surgery
Also called Creos Xenoprotect, Collagen membrane closure, Submucosal membrane technique
Minimally invasive closure of acute oroantral communication using a resorbable heterogeneous collagen membrane placed in a submucosal position. After extraction socket debridement and smoothing of sharp bony margins, the membrane was trimmed to overlap the defect and inserted beneath the mucosa to fully cover the communication. Limited mucoperiosteal elevation was performed without vertical releasing incisions. The membrane was stabilized using horizontal mattress sutures to achieve tension-free coverage and was left to integrate and resorb spontaneously. Standardized postoperative antibiotics, sinus precautions, and follow-up visits were applied.
Buccal advancement flap OAC closureProcedure or surgery
Also called Rehrmann flap, Rehrmann technique, Buccal advancement flap
Conventional surgical closure of acute oroantral communication using a coronally advanced buccal mucoperiosteal flap. Following socket debridement and smoothing of bony margins, a trapezoidal full-thickness flap with vertical releasing incisions was elevated. Periosteal releasing incisions were performed to allow tension-free coronal advancement of the flap over the defect. Primary closure was achieved with interrupted sutures. Postoperative management, including antibiotics, sinus precautions, and scheduled follow-up, was standardized across study groups.
| Study group | Role | What they receive |
|---|---|---|
| Resorbable Collagen Membrane Closure | Experimental | Participants with acute oroantral communication diagnosed within 24 hours after extraction underwent minimally invasive closure using a resorbable heterogeneous collagen membrane (Creos Xenoprotect). After socket debridement and smoothing of sharp bony margins, the membrane was trimmed and inserted in a submucosal position to fully cover the defect. Limited mucoperiosteal elevation was performed without vertical releasing incisions. The membrane was stabilized with horizontal mattress sutures and allowed to integrate and resorb spontaneously. Standardized postoperative care, antibiotics, and follow-up were provided. Receives: Procedure: Resorbable collagen membrane OAC closure |
| Buccal Advancement Flap (Rehrmann) | Active comparator | Participants with acute oroantral communication diagnosed within 24 hours after extraction underwent closure using the conventional Rehrmann buccal advancement flap. Following socket debridement and smoothing of bony margins, a trapezoidal full-thickness mucoperiosteal flap with vertical releasing incisions was elevated, mobilized with periosteal releasing incisions, and advanced coronally to achieve tension-free primary closure. Standardized postoperative care, antibiotics, and follow-up identical to the experimental arm were applied. Receives: Procedure: Buccal advancement flap OAC closure |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in vestibular depth from baseline to 90 days
The primary outcome was the change in oral vestibular depth at the surgical site, measured in millimeters using a calibrated WHO periodontal probe. Measurements were obtained at baseline (day 0) and during follow-up visits. The endpoint reflects preservation of soft tissue architecture after oroantral communication closure. Greater preservation (smaller reduction from baseline) indicates a more favorable clinical outcome for future prosthetic or implant rehabilitation.
Measured: Baseline (day 0) to 90 days postoperatively
Secondary outcomes (4)
Change in keratinized gingiva width
Width of keratinized gingiva at the surgical site measured in millimeters with a calibrated WHO periodontal probe at baseline and follow-up visits. The outcome assesses preservation of keratinized tissue after oroantral communication closure. Greater preservation indicates a more favorable soft tissue result for long-term oral hygiene and prosthetic planning.
Measured: Baseline (day 0) to 90 days postoperatively
Change in alveolar socket width
Buccopalatal width of the post-extraction alveolar socket measured clinically and radiographically at predefined time points. This parameter evaluates dimensional stability of the alveolar ridge following closure of oroantral communication. Smaller reduction from baseline indicates better preservation of ridge architecture.
Measured: Baseline (day 0) to 90 days postoperatively
Postoperative pain intensity (VAS)
Patient-reported pain assessed using a 100 mm Visual Analogue Scale (VAS), where 0 indicates no pain and 100 indicates worst imaginable pain. Patients marked their pain level at each follow-up visit. Lower scores indicate better postoperative comfort.
Measured: Postoperative days 1, 7, and 14
Incidence of postoperative complications
Occurrence of adverse postoperative events including swelling, hematoma, epistaxis, wound dehiscence, persistent oroantral communication, fistula formation, or clinical signs of sinusitis. Events were recorded during scheduled follow-up visits.
Measured: Up to 90 days postoperatively
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted17 Mar 2026
- Study start1 May 2021
- Primary completion1 Dec 2025
- Study completion1 Dec 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Oroantral CommunicationStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Model description
- This was a prospective, non-randomized, parallel-group clinical study comparing two surgical techniques for acute oroantral communication closure. Eligible adult patients diagnosed within 24 hours after maxillary posterior tooth extraction were allocated to either submucosal placement of a resorbable collagen membrane or closure using the Rehrmann buccal advancement flap. All procedures were performed by the same experienced oral surgeon using standardized perioperative protocols. Clinical and radiographic outcomes were evaluated over a 90-day follow-up period.
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 24 participants (actual)
Sponsor and investigators
- Lead sponsor
- Medical University of Silesia
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07476664
- Sponsor's protocol ID
- PCN/0022/KB1/94/20/21
- Acronym
- AOC
- Status last verified
- Feb 2026
- First submitted
- 27 Feb 2026
- Last updated
- 17 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 17 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Acute Oroantral Communication Closure: Resorbable Collagen Membrane vs. Buccal Advancement Flap Outcomes
- ClinicalTrials.gov ID
- NCT07476664
- Acronym / sponsor ID
- AOC / PCN/0022/KB1/94/20/21
- Conditions
- Oroantral Communication, Acute Oroantral Communication, Oroantral Fistula, Post-extraction Maxillary Sinus Communication
- Keywords
- oroantral communication, acute OAC, buccal advancement flap, Rehrmann flap, oral surgery, CBCT bone density, vestibular depth preservation
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 24 participants (actual)
- Lead sponsor
- Medical University of SilesiaUniversity, hospital or other
- Study start
- 1 May 2021 (actual)
- Primary completion
- 1 Dec 2025 (actual)
- Study completion
- 1 Dec 2025 (actual)
- First posted
- 17 Mar 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Oroantral communication (OAC) is an abnormal opening between the oral cavity and the maxillary sinus that may occur after extraction of posterior maxillary teeth. If not treated promptly, it can lead to sinus contamination, chronic infection, and development of an oroantral fistula requiring more complex surgical management. The standard surgical treatment is closure with a buccal advancement flap (Rehrmann technique). However, this method may reduce vestibular depth, displace the mucogingival junction, and decrease the width of keratinized gingiva.
This prospective clinical study compares two surgical approaches for closure of acute OAC diagnosed within 24 hours after tooth extraction: placement of a resorbable collagen membrane beneath the mucosa versus the conventional buccal advancement flap. Clinical and radiographic parameters related to soft tissue architecture, postoperative recovery, and bone healing are evaluated during a 90-day follow-up period.
Detailed description
Oroantral communication (OAC) is a pathological connection between the oral cavity and the maxillary sinus most commonly occurring after extraction of posterior maxillary teeth. The close anatomical relationship between the sinus floor and the roots of maxillary molars and premolars increases the risk of perforation of the Schneiderian membrane during dental extraction. If an OAC is not diagnosed and treated promptly, microbial contamination of the sinus may occur, potentially resulting in chronic maxillary sinusitis and epithelialization of the tract with formation of an oroantral fistula. Early closure of acute defects within 24-48 hours is therefore generally recommended.
The buccal advancement flap described by Rehrmann is the most frequently used surgical technique for closure of acute OAC because of its technical simplicity and predictable closure of the defect. Nevertheless, advancement of the buccal mucoperiosteal flap may alter local soft tissue anatomy, including reduction of vestibular depth, displacement of the mucogingival junction, and loss of keratinized gingiva. These anatomical changes may affect oral hygiene and may complicate future prosthetic or implant therapy.
Biomaterial-based techniques that preserve soft tissue architecture represent a potential alternative approach. Resorbable collagen membranes are widely used in guided tissue regeneration and guided bone regeneration due to their biocompatibility, clot stabilization properties, and barrier function. Heterologous collagen membranes, such as Creos Xenoprotect, are designed to integrate with surrounding tissues and gradually resorb without the need for surgical removal. Their use for closure of acute OAC has been described in clinical reports; however, comparative clinical data against conventional flap techniques remain limited.
The present study is designed as a prospective, non-randomized comparative clinical investigation evaluating two surgical methods for closure of acute oroantral communications diagnosed within 24 hours after extraction of posterior maxillary teeth. Adult patients presenting with clinically and radiographically confirmed OAC are screened for eligibility and allocated to treatment according to the predefined clinical protocol.
In the experimental group, closure of the communication is performed using a resorbable heterogeneous collagen membrane (Creos Xenoprotect) placed in a submucosal position to cover the defect. Limited mucoperiosteal elevation is performed as necessary, and the membrane is stabilized using sutures to achieve tension-free closure.
In the control group, closure is performed using the conventional Rehrmann buccal advancement flap. After preparation of the extraction socket, a trapezoidal mucoperiosteal flap with vertical releasing incisions is elevated, mobilized using periosteal releasing incisions, and advanced coronally to achieve primary closure of the defect.
The size of the oroantral communication is measured clinically using a calibrated periodontal probe and confirmed with limited-field cone-beam computed tomography (CBCT). Standardized perioperative management is applied in both groups, including socket debridement, smoothing of bony margins, sinus precautions, and scheduled postoperative follow-up.
Study design
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 2
- Model description
- This was a prospective, non-randomized, parallel-group clinical study comparing two surgical techniques for acute oroantral communication closure. Eligible adult patients diagnosed within 24 hours after maxillary posterior tooth extraction were allocated to either submucosal placement of a resorbable collagen membrane or closure using the Rehrmann buccal advancement flap. All procedures were performed by the same experienced oral surgeon using standardized perioperative protocols. Clinical and radiographic outcomes were evaluated over a 90-day follow-up period.
| Arm | Type | Receives |
|---|---|---|
| Resorbable Collagen Membrane Closure | Experimental | Procedure: Resorbable collagen membrane OAC closureParticipants with acute oroantral communication diagnosed within 24 hours after extraction underwent minimally invasive closure using a resorbable heterogeneous collagen membrane (Creos Xenoprotect). After socket debridement and smoothing of sharp bony margins, the membrane was trimmed and inserted in a submucosal position to fully cover the defect. Limited mucoperiosteal elevation was performed without vertical releasing incisions. The membrane was stabilized with horizontal mattress sutures and allowed to integrate and resorb spontaneously. Standardized postoperative care, antibiotics, and follow-up were provided. |
| Buccal Advancement Flap (Rehrmann) | Active comparator | Procedure: Buccal advancement flap OAC closureParticipants with acute oroantral communication diagnosed within 24 hours after extraction underwent closure using the conventional Rehrmann buccal advancement flap. Following socket debridement and smoothing of bony margins, a trapezoidal full-thickness mucoperiosteal flap with vertical releasing incisions was elevated, mobilized with periosteal releasing incisions, and advanced coronally to achieve tension-free primary closure. Standardized postoperative care, antibiotics, and follow-up identical to the experimental arm were applied. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (7 listed)
- Adults aged 18 years or older
- Acute oroantral communication diagnosed within 24 hours after extraction of a maxillary posterior tooth
- General health status permitting outpatient dental surgery
- Indication for single-tooth extraction in the posterior maxilla
- Systemic conditions not contraindicating minor oral surgery
Key exclusion criteria (10 listed)
- Oroantral communication present for more than 24 hours
- Chronic inflammatory disease of the maxillary sinus
- History of head and neck neoplastic disease or its treatment
- Pregnancy
- Systemic diseases preventing outpatient surgical treatment
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Resorbable collagen membrane OAC closureAlso: Creos Xenoprotect, Collagen membrane closure, Submucosal membrane techniqueMinimally invasive closure of acute oroantral communication using a resorbable heterogeneous collagen membrane placed in a submucosal position. After extraction socket debridement and smoothing of sharp bony margins, the membrane was trimmed to overlap the defect and inserted beneath the mucosa to fully cover the communication. Limited mucoperiosteal elevation was performed without vertical releasing incisions. The membrane was stabilized using horizontal mattress sutures to achieve tension-free coverage and was left to integrate and resorb spontaneously. Standardized postoperative antibiotics, sinus precautions, and follow-up visits were applied. | Procedure or surgery | Resorbable Collagen Membrane Closure |
| Buccal advancement flap OAC closureAlso: Rehrmann flap, Rehrmann technique, Buccal advancement flapConventional surgical closure of acute oroantral communication using a coronally advanced buccal mucoperiosteal flap. Following socket debridement and smoothing of bony margins, a trapezoidal full-thickness flap with vertical releasing incisions was elevated. Periosteal releasing incisions were performed to allow tension-free coronal advancement of the flap over the defect. Primary closure was achieved with interrupted sutures. Postoperative management, including antibiotics, sinus precautions, and scheduled follow-up, was standardized across study groups. | Procedure or surgery | Buccal Advancement Flap (Rehrmann) |
Primary outcome
Change in vestibular depth from baseline to 90 days
Time frame: Baseline (day 0) to 90 days postoperatively
The primary outcome was the change in oral vestibular depth at the surgical site, measured in millimeters using a calibrated WHO periodontal probe. Measurements were obtained at baseline (day 0) and during follow-up visits. The endpoint reflects preservation of soft tissue architecture after oroantral communication closure. Greater preservation (smaller reduction from baseline) indicates a more favorable clinical outcome for future prosthetic or implant rehabilitation.
4 secondary outcomes
Change in keratinized gingiva width
Time frame: Baseline (day 0) to 90 days postoperatively
Change in alveolar socket width
Time frame: Baseline (day 0) to 90 days postoperatively
Postoperative pain intensity (VAS)
Time frame: Postoperative days 1, 7, and 14
Incidence of postoperative complications
Time frame: Up to 90 days postoperatively
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 17 Mar 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Resorbable collagen membrane OAC closure and Buccal advancement flap OAC closure in people with Oroantral Communication and Acute Oroantral Communication, run by Medical University of Silesia at 1 site in Poland.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 7 inclusion and 10 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 17 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Poland. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in vestibular depth from baseline to 90 days (time frame: Baseline (day 0) to 90 days postoperatively). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 17 Mar 2026.