Impact of Two Flap Advancement Techniques and Periosteal Suturing on Graft Displacement During Guided Bone Regeneration

This preclinical ex vivo porcine study aimed to evaluate the effects of two flap advancement techniques and periosteal suturing (PS) on graft material displacement during primary wound closure in guided bone regeneration (GBR). Secondary objectives included assessing flap advancement and the impact of soft tissue characteristics on graft displacement. Standardized two-walled horizontal bone defects were created in second premolar sites of pig hemimandibles. Sites were randomized to using either full-thickness flaps with modified periosteal releasing incisions (MPRI) or combination flaps using the mucosal detachment technique (MDT), both with and without PS. Cone-beam computed tomography was used to measure changes in graft material thickness (GMT) at seven incremental levels (L0-L6) relative to the implant platform, before and after primary wound closure. Keratinized mucosa width (KMW), flap thickness (FT), and flap advancement (FA) were also recorded. Sixty-eight horizontal bone augmentation procedures were performed on 34 pig hemimandibles, divided into four groups (MDT+PS, MDT-PS, MPRI+PS, MPRI-PS). Mean overall change in GMT at L0 was -24.5% ± 14.0% for MPRI and - 23.0% ± 14.3% for MDT (p ≥ 0.085). PS reduced graft displacement (-14.2% ± 11.5%) compared with no PS (-33.2% ± 16.9%, p < 0.001). FA was 8.3 ± 1.1 mm (MPRI) and 8.3 ± 1.5 mm (MDT). The mean KMW was 6.8 ± 0.9 mm, and FT ranged from 0.8 to 1.6 mm. PS significantly reduced graft material displacement during primary wound closure, while flap advancement techniques and soft tissue characteristics had no impact on graft stability. Both surgical techniques provided sufficient flap advancement for primary wound closure.