The vertical course of bone regeneration in maxillary sinus floor augmentations: A histomorphometric analysis of human biopsies

Abstract

Background: Maxillary sinus floor augmentation (MSFA) is a well-established and predictable augmentation method in severely resorbed maxillae. However, data on the vertical course of bone graft consolidation within the maxillary sinus are rare. The aim of the present study was to quantify the vertical distribution of new bone formation (nBF) in MSFA and to characterize the vertical gradient of bone graft consolidation. Methods: Eighty-five human sinus biopsies were harvested 6 ± 1 months after MSFA. Histological thin-ground sections were prepared and histomorphometrically analyzed. The volume of newly formed bone (nBV/TV) was measured in serial zones of 100 μm proceeding from the bottom of the sinus floor (SF) up to the apical top of the biopsy. The gradient of nBV/TV within the augmentation area was determined by the vertical distribution of nBV/TV along these zones. Results: In the premolar region, nBV/TV slightly declined from 20.4% in the zone adjacent to the SF to 17.7% at a distance of 8 mm. The gradient was steeper in the molar region: nBV/TV decreased from 18.7% to 12.8%. This decline was even more distinct when the volume fraction and the height of the residual bone of the SF were low. Conclusions: nBF follows a gradient from native bone of the SF towards the apical part of the augmentation area. The distance to primordial bone thus plays a critical role for bone regeneration in MSFA, particularly in the molar region.

Does new bone formation vary in different sites within the same maxillary sinus after lateral augmentation? A prospective histomorphometric study

“…Our findings indirectly confirmed a very recent investigation evaluating the vertical gradient of bone graft consolidation in biopsies harvested 6 months after lateral sinus augmentation (Beck et al, 2021 ). This latter study showed that %NFMT gradually decreases from sinus floor towards the apical part of the augmentation area: this negative gradient was moderate in the premolar area and steeper in the molar area.…”

Radiographic and Histomorphometric Evaluation of Biomaterials Used for Lateral Sinus Augmentation: A Systematic Review on the Effect of Residual Bone Height and Vertical Graft Size on New Bone Formation and Graft Shrinkage

“…Similarly, Corbella et al hypothesized that if the sinus floor had only a thin layer of cortical bone, a lower percentage of NBF was to be expected, as compared to less atrophic cases in which the additional presence of cancellous bone could guarantee better regeneration potential [ 34 ]. Since the regenerative potential starts from the residual bone, NBF may also be affected by the harvesting technique and by the vertical gradient of graft consolidation in the collected specimens [ 71 ]. Beck et al, analysing histological thin-ground sections, demonstrated that NBF decreased with increasing distance from the residual sinus floor since the residual graft encapsulated by fibrous tissue had remained in the apical part of the augmented area [ 71 ].…”

“…Since the regenerative potential starts from the residual bone, NBF may also be affected by the harvesting technique and by the vertical gradient of graft consolidation in the collected specimens [ 71 ]. Beck et al, analysing histological thin-ground sections, demonstrated that NBF decreased with increasing distance from the residual sinus floor since the residual graft encapsulated by fibrous tissue had remained in the apical part of the augmented area [ 71 ].…”

“…The obtained results suggested that a lower Schneiderian membrane elevation may be sufficient to trigger its osteogenic potential efficiently, as compared to grafting a greater amount of biomaterial, which would be counterproductive. Similarly, Beck et al also concluded that a large augmentation height, particularly in the molar region, would not promote high NBF in an apical area within the grafted region [ 71 ].…”

Association between Cone-Beam Computed Tomography and Histological and Immunohistochemical Features in Periapical Lesions Correlated with Thickened Maxillary Sinus Mucosa

“…Healing after periapical lesions is of utmost importance, especially when considering the subsequent treatment plan that can involve implant placement or sinus lifting. The extent of the periapical lesion dictates the size of the osseous defect that results after dental extraction [ 45 ]. As such, the inflammatory infiltrate can play a major role in healing after dental extraction or apical resection [ 11 , 46 ].…”