Dual fixation for FGG in the posterior mandible: 17% shrinkage and no complications at 12 months

Achieving adequate keratinized tissue width (KTW) around implants in the posterior mandible remains one of the more demanding soft tissue challenges in implantology. The free gingival graft (FGG) is the gold standard for KTW augmentation, yet graft contraction — particularly in a region subject to muscular pull and limited access — can significantly undermine the final result. This retrospective case series by Yang et al. introduces a Dual Anchoring Technique (DAT) designed to mechanically stabilize the graft during the critical healing phase, thereby reducing shrinkage and improving dimensional predictability.

The study enrolled 25 systemically healthy patients (49 implant sites) presenting with KTW less than 2 mm following bone augmentation procedures. The DAT combines two fixation elements: orthodontic anchor screws, placed at the coronal margin of the graft to prevent apical displacement, and membrane tacks, used to secure the graft body against the periosteum. This dual fixation system addresses the main vector forces responsible for graft migration and contraction in the posterior mandible. The primary outcome was KTW change from baseline (T₀) to 12 months (T₅). Secondary outcomes included graft shrinkage rate, operative time, complications, and patient-reported outcome measures via VAS scores.

Results were clinically compelling. Mean KTW increased from 0.67 ± 0.12 mm at baseline to 11.00 ± 0.87 mm at one month, stabilizing at 8.70 ± 0.84 mm at 12 months — a net gain of 8.02 ± 0.82 mm (p < .001). Graft shrinkage at 12 months averaged 17.48 ± 3.41%, with 85% of total contraction occurring within the first three months. Operative times were efficient: 26.40 ± 1.90 min for single-site procedures and 33.31 ± 2.08 min for two-site cases. No intraoperative or postoperative complications were recorded, and VAS pain scores reached negligible levels by day 14, suggesting good patient tolerance.

The shrinkage rate of approximately 17.5% compares favorably with figures reported in the literature for conventional FGG techniques, which typically range from 25% to over 40% depending on the fixation method and site. The near-complete contraction within the first three months reinforces the importance of early mechanical stabilization — precisely the window in which the DAT exerts its greatest mechanical influence.

For the practicing periodontist or implantologist, the take-home message is straightforward: in the posterior mandible, where anatomy and muscular dynamics conspire against graft stability, a dual fixation strategy using readily available hardware can meaningfully improve outcomes. The technique is reproducible, time-efficient, and associated with low morbidity. Limitations inherent to the retrospective design and the absence of a control group warrant cautious interpretation, but the consistency of results across 49 sites over 12 months provides a credible foundation for prospective investigation.