Department of Orthodontics, University Medical Center Mainz, Mainz, Germany.
Clin Oral Implants Res. 2011 Jun;22(6):664-8. doi: 10.1111/j.1600-0501.2010.02021.x. Epub 2010 Oct 6.
To evaluate the necessity of three-dimensional imaging (computed tomography [CT]/cone-beam computed tomography [CBCT]) for paramedian insertion of palatal implants.
Lateral radiographs and CBCT scans were performed from 18 human skulls. For lateral cephalometry, the nasal floor (right/left) and the oral hard palate of all skulls were lined with a tin foil for contrast enhancement. The quantity of vertical bone as measured on lateral radiographs was compared with CBCT measurements obtained in median and parasagittal planes and at minimum bone height. Spearman's rank correlation coefficients were determined for bivariate correlation analysis.
The median palatal bone height on CBCT (mean 8.98 mm; standard deviation [SD] 3.4) was markedly higher than the vertical height seen on lateral radiographs (mean 6.6 mm; SD 3.2). Comparing lateral cephalometry with CBCT, the strongest association was observed at the minimum palatal bone height (r=0.926; P<0.001; Spearman's rank correlation coefficient).
Lateral radiographs allow accurate and adequate assessment of vertical bone before paramedian insertion of palatal implants. The vertical bone dimension as displayed on lateral cephalometry reflects the minimum bone height rather than maximum bone in the median plane. Therefore, a preoperative CT or CBCT is only indicated when the lateral cephalometry reveals a marginal quantity of bone.
评估三维成像（计算机断层扫描[CT]/锥形束 CT[CBCT]）在腭部植入体正中插入中的必要性。
对 18 个人颅骨进行侧位 X 线片和 CBCT 扫描。为了进行侧位头影测量，所有颅骨的鼻底（右侧/左侧）和口腔硬腭均用锡箔衬里以增强对比度。侧位 X 线片上测量的垂直骨量与正中矢状面和旁矢状面以及最小骨高度的 CBCT 测量值进行了比较。采用 Spearman 秩相关系数进行了双变量相关分析。
CBCT 上的正中腭骨高度（平均值 8.98mm；标准差[SD]3.4）明显高于侧位 X 线片上的垂直高度（平均值 6.6mm；SD3.2）。将侧位头影测量与 CBCT 进行比较，在最小腭骨高度处观察到最强的相关性（r=0.926；P<0.001；Spearman 秩相关系数）。
侧位 X 线片可在正中插入腭部植入体之前准确充分地评估垂直骨量。侧位头影测量所显示的垂直骨维度反映了最小骨高度，而不是正中平面的最大骨高度。因此，仅当侧位头影测量显示骨量不足时，才需要进行术前 CT 或 CBCT。
