Preoperative buccal bone volume predicts long‐term graft retention following augmentation in the esthetic zone: A retrospective case series

OBJECTIVES: Buccal bone augmentation in the esthetic zone is routinely used to achieve optimal clinical outcomes. Nonetheless, long‐term data are sparse, and it is unknown how baseline buccal bone volume affects the retention of the augmented volume over time. MATERIAL AND METHODS: This is a long‐term follow‐up retrospective case series. After a preoperative computed tomography scan, implants were placed in the anterior maxilla following guided bone regeneration, autogenous block grafting, or both. At the follow‐up, patients received a computed tomography scan and a clinical examination. Buccal bone volume was the primary outcome. Buccal bone thickness, peri‐implant, and esthetic parameters were secondary outcomes. RESULTS: After a median follow‐up of 6.7 years (interquartile range: 4.9–9.4), 28 implants in 19 patients (median age at augmentation: 43.3 years, interquartile range: 34.4–56.7, 53% female) were followed up. Preoperative buccal bone volume at baseline (V(0)) showed a moderate correlation to final buccal bone volume (V(t), r(s) = .43) but a strong correlation to the absolute volumetric change (ΔV = V(t)–V(0), r(s) = −.80). A linear mixed model for V(t) had a large intercept of 91.39 (p < .001) and a rather small slope of .11 for V(0) (p = .11). Observed differences between treatments were not statistically significant in the mixed model. V(0) above 105 mm(3) predicted a negative volume change (ΔV < 0) with a specificity of 100% and a sensitivity of 96%. CONCLUSIONS: The results suggest higher gains in sites with lower V(0) and point to a cutoff V(0) above which the augmented volume is not retained long‐term.