BACKGROUND: The thin labial alveolar wall (LAW) of anterior maxillary teeth is prone to resorption after flap surgery, jeopardizing aesthetic outcomes. This study evaluated whether extended guided bone regeneration (GBR) to cover the LAW of adjacent teeth mitigates this bone loss. METHODS: In this retrospective cohort study, we categorized adjacent teeth into three groups according to the intraoperative extension of the graft relative to the LAW: Non-Extended GBR (NE-GBR; graft confined to edentulous site), Partially Extended GBR (PE-GBR; graft on partial BBW), and Fully Extended GBR (FE-GBR; graft covering BBW to the crest). Horizontal LAW thickness and vertical distance from cementoenamel junction to the alveolar crest were measured on superimposed pre-operative and 6-month post-operative CBCT scans. RESULTS: Analysis included 135 adjacent teeth (80 patients). Significant horizontal resorption occurred in the NE-GBR (- 0.40 ± 0.32 mm) and PE-GBR (- 0.43 ± 0.44 mm) groups (p < 0.001), while the FE-GBR group maintained stable dimensions (0.15 ± 0.75 mm, p = 0.523). Vertically, the FE-GBR group showed a significant dimensional gain (0.43 ± 1.10 mm, p < 0.001), unlike the resorption seen in other groups. Mixed-effects models confirmed FE-GBR as a significant positive predictor for both horizontal (β = 0.48, p < 0.001) and vertical (β = 0.48, p = 0.001) dimensional preservation. CONCLUSIONS: Fully extended GBR to cover the LAW up to the crest appears to counteract post-surgical reduction, better preserving radiographic alveolar ridge dimensions in the aesthetic zone over a 6-month period. TRIAL REGISTRATION: This study protocol was approved by the Institutional Review Board (LCYJ20250303005) and was registered in the Chinese Clinical Trial Registry (ChiCTR2500099603).
Zeng et al. (Wed,) studied this question.