上顎前方歯槽突起部に下顎骨片を用いてベニアグラフトした症例の 臨床的・放射線学的検討

抄録

Purpose:To assess quantitative changes in bone width before and after bone grafting in cases of veneer grafting to the maxillary ridge with block bone harvested from the mandible and to measure the width of the labial/buccal bones of implant bodies 5 years or more after superstructure placement.
Materials and Methods:We assessed 14 sites in 11 cases. The ridge bone width was measured at the time of veneer grafting as well as upon implant placement (four to six months later). The measurement sites were the 5-, 10-, and 15-mm horizontal bone widths at 5-mm intervals going vertically toward the floor of the nasal cavity, with the references points of the crest of the alveolar process. For cases in which five or more years had elapsed since the superstructure placement, 21 sites where implant bodies were placed were imaged by conebeam computed tomography(CT) , and the widths of the labial/buccal bone of the implant body were measured and assessed.
Results:The ridge bone width at the time of veneer grafting was 2.3±0.8 mm at the 5-mm position, 3.7±1.4 mm at the 10-mm position, and 5.3±1.8 mm at the 15-mm position going toward the floor of the nasal cavity from the crest of the alveolar process. The bone widths of the same sites again upon implant placement were 6.6±0.7 mm at the 5-mm position, 8.0±1.3 mm at the 10-mm position, and 8.7±1.4 mm at the 15-mm position. The diameter width measurements of the labial/buccal bone of the implants in 15 out of 21 sites where five or more years had elapsed since the superstructure placement and visualization with cone-beam CT was possible were 1.8±0.6 mm at the 5-mm position and 2.3±0.6 mm at the 10-mm position from the platform.
Conclusion:Veneer grafting with block bone harvested from the mandible to the maxillary alveolar process resulted in the ability to acquire the necessary horizontal bone mass for implant placement. Even when five years had elapsed since the superstructure placement, the labial/buccal bone of the implant body had maintained a thickness of 1.5 mm or greater, suggesting that this state will continue to be maintained.