Atrophic maxillary floor augmentation by mineralized human bone allograft in sinuses of different size: an histologic and histomorphometric analysis

Objective The aims of this work were to histologically examine the healing of mineralized human bone allograft (MHBA) in sinus augmentation for elevating a severe maxillary atrophy ridge (< 2 mm residual ridge height) and to correlate the results to the sinus cavity size. Material and methods A two-stage protocol was conducted in 23 patients, all having crestal bone < 2 mm. A mixture of 80/20 cortical/cancellous of MHBA particles was used to augment sinus using the lateral window approach in narrow (NS; < 15 mm bucco-palatal distance) and wide (WS; >= 15 mm bucco-palatal distance) sinuses, based upon computerized tomography (CT) assessment. A bone core biopsy was taken at implant placement, 6 and 9 months after surgery. Microradiography, histology and histochemistry of methacrylate-embedded sections were performed to analyze and to evaluate the bone and graft amount. Results Newly formed bone around MBHA particles was found in all 28 biopsies. Bone showed a woven structure at 6 months after surgery and a lamellar structure 9 months after surgery. At 6 months after surgery, the 13 NS and 15 WS had 30.5 +/- 8.8% and 20.7 +/- 4.9% mean +/- SD bone formation, respectively. At 9 months after surgery, it was 38.8 +/- 7% (NS) and 30.7 +/- 3% (WS). Residual graft was about 16% (6 months) and 6% (9 months), in both NS and WS. The Mann-Whitney test showed a greater bone formation in NS than in WS (P < 0.005). Conclusions The used 80/20 MHBA mixture appears to promote, in the severe atrophic maxilla, a satisfactory bone formation. Our results prove that the larger the sinus, the longer the maturation time needed to achieve a suitable amount of new bone formation. To cite this article:Maria Soardi C, Spinato S, Zaffe D, Wang H-L. Atrophic maxillary floor augmentation by mineralized human bone allograft in sinuses of different size: an histologic and histomorphometric analysis.Clin. Oral Impl. Res. 22, 2011; 560-566doi: 10.1111/j.1600-0501.2010.02034.x.