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.
