Knezović-Ziatarić Dubravka, Celebić Asja
Department of Prosthodontics, School of Dental Medicine, University of Zagreb, Croatia.
Int J Prosthodont. 2003 Nov-Dec;16(6):661-5.
The purpose of the study was to determine the changes in bone mineral density of the mandible in complete and removable free-end saddle denture wearers over a 6-month period.
Twenty removable partial denture patients and 20 complete denture wearers participated. Two dental panoramic radiographs were taken from each patient, the first prior to denture delivery and the second after 6 months of denture wearing. Bone mineral density measurements were performed on panoramic radiographs with a five-step copper stepwedge attached to each film cassette. Bone mineral density values of the measured regions of interest were expressed in equivalents of the stepwedge thickness (mm).
The results revealed minor changes in bone mineral density values of the examined regions in the 6-month period. Under the distal end of complete denture saddles, the bone mineral density values decreased, whereas the values under the distal end of removable partial dentures increased. However, the difference between the first and second measurements was not significant. In each of the examined groups, the bone mineral density values at the gonion increased significantly by approximately 20%. This was attributed to the increased strain forces of the masseter muscle at the gonion after denture delivery.
Significant increase of bone mineral density values was registered 2 mm above the gonion in both complete and removable partial denture wearers. Age and gender were not related to the bone mineral density changes over a 6-month period.
本研究的目的是确定全口可摘游离端鞍基义齿佩戴者和局部可摘义齿佩戴者在6个月期间下颌骨骨密度的变化。
20名局部可摘义齿患者和20名全口义齿佩戴者参与了研究。为每位患者拍摄两张牙科全景X线片，第一张在义齿交付前拍摄，第二张在佩戴义齿6个月后拍摄。使用附着在每个暗盒上的五步铜阶梯楔对全景X线片进行骨密度测量。所测量感兴趣区域的骨密度值以阶梯楔厚度（mm）的当量表示。
结果显示，在6个月期间，所检查区域的骨密度值有轻微变化。在全口义齿鞍基远端下方，骨密度值下降，而局部可摘义齿远端下方的骨密度值上升。然而，第一次和第二次测量之间的差异不显著。在每个检查组中，下颌角处的骨密度值显著增加了约20%。这归因于义齿交付后咬肌在下颌角处的应变力增加。
全口义齿和局部可摘义齿佩戴者在下颌角上方2mm处的骨密度值均显著增加。年龄和性别与6个月期间的骨密度变化无关。
