Alveolar Bone Morphologic Predictors for Guided Bone Regeneration Outcome in Anterior Maxilla

This study aimed to explore the influence of alveolar bone morphologic variables on the outcome of guided bone regeneration (GBR) in the anterior maxilla region.

Twenty-eight patients who received single maxillary anterior tooth delayed implant placed simultaneously with GBR were recruited. Baseline data including age, gender, implant site, implant brand, and bone graft materials were recorded. The resorption rate of the grafted bone (RRGB), labial bone width at 0 mm, 2 mm, and 4 mm apical to the implant platform at Tn (LBW0_{Tn, LBW2}), implant angulation (IA), maximum bone graft thickness (MBGT), bone graft volume (BGV), and the initial bone morphologic variables bone concavity depth (BCD) and bone concavity angulation (BCA) were measured. The Pearson correlation analysis, analysis of variance (ANOVA), and optimal binning method were used to explore the potential predictors for GBR.

Among 28 patients, the labial bone width of implant and bone graft volume decreased significantly when measured 6 months after surgery. The mean percentage of RRGB was 49.78%. RRGB was not correlated with gender, age, bone graft material, IA, MBGT, bone graft volume at T1, implant site, and implant brand (P > .05). BCD and BCA were each moderately correlated with RRGB (r = -0.872 [P < .001] and r = 0.686 [P < .001], respectively). A BCD ≥1.03 mm and a BCA <155.30° resulted in a significantly lower percentage of RRGB (P < .001).

A significant grafted bone materials volume reduction was detected after GBR with collagen membrane and deproteinized bovine bone mineral (DBBM). The initial bone morphology can influence GBR outcome, and a bone concavity with a depth ≥1.03 mm and an angulation <155.30° led to a lower RRGB. BCD and BCA can be used as variables to predict the outcome of GBR.