Schmidt E F, Webber R L, Ruttimann U E, Loesche W J
Department of Oral Biology, University of Michigan, School of Dentistry, Ann Arbor 48109.
J Periodontol. 1988 Oct;59(10):633-8. doi: 10.1902/jop.1988.59.10.633.
Changes in the periodontal alveolar bone are often evaluated by comparing a series of radiographs taken over time. This investigation used a technique that allowed the image registration to be geometrically standardized each time a radiograph was taken. Radiographs of 24 patients from an ongoing double-blind, clinical study using metronidazole were obtained: (1) before any treatment, (2) at the completion of scaling and root planing and surgery (when performed) and (3) during the maintenance phase. One hundred six (106) paired comparisons were analyzed by subtraction radiography using a computerized system. Of these, 95 (89%) exhibited a minimal degree of geometric distortion and could be successfully substracted. Most areas (67%) showed no change in bone structure following periodontal treatment. Bone gain was noted in 12% of the sites examined, while bone loss was seen in 21% of the sites. This bone loss was statistically associated with sites that had received some form of surgical treatment.
牙周牙槽骨的变化通常通过比较一系列随时间拍摄的X光片来评估。本研究采用了一种技术，每次拍摄X光片时都能使图像配准在几何上标准化。从一项正在进行的使用甲硝唑的双盲临床研究中获取了24名患者的X光片：（1）在任何治疗前，（2）在洁治和根面平整及手术（如果进行）完成时，以及（3）在维护阶段。使用计算机系统通过减影放射摄影分析了106对配对比较。其中，95对（89%）表现出最小程度的几何失真，并且可以成功相减。大多数区域（67%）在牙周治疗后骨结构没有变化。在所检查的部位中，12%有骨量增加，而21%的部位有骨丢失。这种骨丢失在统计学上与接受过某种形式手术治疗的部位相关。
