Relationship between flap microcirculation and hard tissue changes following alveolar ridge augmentation: a prospective case series.

Objectives: To assess blood flow alterations after horizontal Guided Bone Regeneration (GBR) and to evaluate correlations between blood flow and hard tissue changes.

Method and materials: Twelve mandibular surgical sites were involved in the current case series. GBR was carried out using a split-thickness flap design. Blood circulation was assessed with Laser Speckle Contrast Imaging at baseline as well as 1, 4, 6, 11, 13, 20, 27, and 34 days after the surgery, subsequently on a monthly basis until 6 months. Hard tissue alterations were measured horizontally and vertically using linear measurements. The first measurement point was 2 mm distal to the distal surface of the last tooth; additional measurement points were placed every 3 mm up to the 15th mm. Volumetric hard tissue loss and gain were also assessed.

Results: Baseline blood circulation was statistically significantly higher on the buccal side. On the first postoperative day, all regions presented a statistically significant decrease in blood flow circulation. The buccal-inner region presented significant ischemia on day 6. Mean volumetric hard tissue gain and loss were 712.62 ± 317.08 mm3 and 222.431 ± 103.19 mm3, respectively. Mean baseline alveolar ridge width was 4.82 ± 1.02 mm, 6 months ridge width averaged 7.21 ± 0.99 mm. Vertical resorption measured 1.24 ± 0.5 mm. Correlations between blood flow changes and hard tissue alterations were only found on Day 34 and Day 60.

Conclusion: Laser Speckle Contrast Imaging is an efficient method to measure flap microcirculation. No correlation was found between flap microcirculation changes hard tissue and alterations.