Yamaura T, Abe S, Tamatsu Y, Rhee S, Hashimoto M, Ide Y
Department of Anatomy, Tokyo Dental College, Chiba, Japan.
Bull Tokyo Dent Coll. 1998 Nov;39(4):287-92.
The placement of dental implants in the molar region of the maxilla is often difficult because of the presence of the maxillary sinus. It has recently been postulated that the pillar of bone consisting of the maxillary tuberosity, the pterygoid process of the sphenoid bone, and the pyramidal process of the palatine bone, which is located at the posterior part of the maxilla, is suitable for fixing implants in the maxilla. In this study, we morphometrically examined the figure of the pillar of bone in dentate and edentulous maxillary bone specimens. The posterior part of the maxilla, including the pterygoid process of the sphenoid bone and pyramidal process of the palatine bone was embedded in polyester resin. Serial transverse sections 500 microns thick were prepared, and soft X-ray photographs were taken. Three-dimensional images of the pillar of bone were reconstructed from the contour in the soft X-ray images, and the height inclination angles, and volume of the pillar were measured. In dentulous specimens, the imaginary approximation line of the center of the gravity of the pillar of bone in the posterior part of the maxilla was inclined antero-posteriorly at an angle of 76.5 +/- 3.0 degrees from the anterior to posterior direction against the Frankfurt horizontal plane and bucco-palatally at 17.2 +/- 2.7 degrees to the medial direction against the sagittal plane. In edentulous specimens, the pillar of bone was inclined antero-posteriorly at 67.3 +/- 5.0 degrees against the Frankfurt horizontal plane and bucco-palatally at 14.1 +/- 2.1 degrees against the sagittal plane. The volume of the pillar of bone was greater in edentulous specimens than those in the dentulous specimens. The present results will enable setting up a standard for implant surgery dentulous specimens.
由于上颌窦的存在，在上颌磨牙区植入牙种植体往往具有挑战性。最近有研究推测，位于上颌后部由上颌结节、蝶骨翼突和腭骨锥突组成的骨柱适合于上颌种植体的固定。在本研究中，我们对有牙和无牙上颌骨标本中的骨柱形态进行了测量分析。将上颌后部，包括蝶骨翼突和腭骨锥突，嵌入聚酯树脂中。制备了500微米厚的连续横切片，并拍摄了软X线照片。根据软X线图像中的轮廓重建骨柱的三维图像，并测量骨柱的高度、倾斜角度和体积。在有牙标本中，上颌后部骨柱重心的假想近似线相对于法兰克福水平面从前往后倾斜76.5±3.0度，相对于矢状面从颊侧到腭侧朝内侧倾斜17.2±2.7度。在无牙标本中，骨柱相对于法兰克福水平面从前往后倾斜67.3±5.0度，相对于矢状面从颊侧到腭侧朝内侧倾斜14.1±2.1度。无牙标本中骨柱的体积大于有牙标本。本研究结果将有助于建立有牙标本种植手术的标准。
