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 ) showed a moderate correlation to final buccal bone volume (V , r  = .43) but a strong correlation to the absolute volumetric change (ΔV = V -V , r  = -.80). A linear mixed model for V had a large intercept of 91.39 (p < .001) and a rather small slope of .11 for V (p = .11). Observed differences between treatments were not statistically significant in the mixed model. V above 105 mm 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 and point to a cutoff V above which the augmented volume is not retained long-term.