Grafting the Nasal Cavity with 100% Anorganic Bovine Bone: A Clinical and Histomorphometric Pilot Report

Purpose: The aim of the present study was to evaluate bone formation and survival rates for implants after nasal cavity grafting using exclusively anorganic bovine bone (ABB) by means of clinical, radiographic, and histologic/histomorphometric examinations. Materials and Methods: Twelve subjects with edentulous atrophic maxillae were screened for the study; four required bilateral and eight required unilateral nasal cavity grafting. A full-thickness flap was raised to determine the position for the nasal window between the anterior wall of the sinus and the lateral wall of the piriform aperture. A window, 5 to 6 mm wide and 10 to 13 mm high, was created. The window was infractured into the nasal cavity to allow the ABB to be pushed inside and was then covered with a collagen membrane. Cone beam computed tomography (CBCT) was performed before grafting (during screening), after grafting, and 6 months later. Eight months after grafting, from the 16 sites grafted, biopsy cores were taken from three patients using a 2.5-mm trephine and processed to evaluate the percentages of new bone, marrow space, and residual ABB. One screw-form implant was placed in each grafted site and loaded after 3 months. After at least 6 months of loading, the fixed prostheses were removed and all implants placed in grafted areas were tested for mobility. Results: The 6-month CBCTs clearly showed the radiopaque material inside the nasal cavity. The histomorphometric measurements showed 33.34% new bone, 30.30% marrow space, and 36.52% remaining ABB. All implants were osseointegrated and free of pain, infection, and mobility. All implants remained stable at a mean of 13 months after loading (range, 6 to 24 months). Conclusions: The clinical, radiographic, and histomorphometric results showed that nasal cavity grafting with ABB can be an excellent alternative in patients with extensively atrophic maxillae.