Jung T, Tschernitschek H, Hippen H, Schneider B, Borchers L
Department of Prosthetic Dentistry, School of Dentistry, Medical University of Hanover, Germany.
Dentomaxillofac Radiol. 2004 Mar;33(2):119-24. doi: 10.1259/dmfr/13491574.
The styloid process (SP) is often denoted as elongated when it is longer than 30 mm or 33 mm. These dimensions, based on early reports, do not respect the natural variation of the SP. The aim of this study is to investigate the natural variation of the length of the SP. Knowing this variation is a prerequisite for consistent terminology in anatomy and anthropology; it is essential for the classification of the SP as elongated on panoramic radiographs (PRs).
1000 consecutive PRs of a normal population were retrieved from inactive files at the Dental School of the Hannover Medical University. Measurements of the length of the SPs were made directly on the radiographs from the caudal margin of the tympanic plate to the tip of the SP.
On 521 of the 1000 PRs the length of the SP could be measured at least on one side. As there was no significant difference between distributions on the left and right side, both sides were combined to give a total of 837 measurements. The median was 28.0 mm, the interquartile range was from 23.0 mm to 36.0 mm. The distribution depends significantly on age and gender. The 90th percentile varies between 42 mm for women under 35 years and 49 mm for men aged over 35 years.
The medians in our sample correspond to the thresholds for elongated SP quoted in the literature. Our results show that these thresholds are too low, since they are exceeded in 50% of normal patients. We propose that the SP should be considered to be elongated only if its length exceeds 45 mm, which corresponds to the average of the 90th percentiles for different sex and age groups.
当茎突（SP）长度超过30毫米或33毫米时，通常被认为是过长。基于早期报告的这些尺寸并未考虑到SP的自然变异。本研究的目的是调查SP长度的自然变异。了解这种变异是解剖学和人类学中术语一致性的先决条件；对于在全景X线片（PR）上判定SP过长至关重要。
从汉诺威医科大学牙科学院的闲置档案中检索出1000例正常人群的连续PR。直接在X线片上测量SP的长度，从鼓室板的尾缘至SP的尖端。
在1000例PR中的521例上，至少能在一侧测量SP的长度。由于左右两侧分布无显著差异，将两侧数据合并，共得到837次测量结果。中位数为28.0毫米，四分位间距为23.0毫米至36.0毫米。分布情况显著取决于年龄和性别。第90百分位数在35岁以下女性中为42毫米，在35岁以上男性中为49毫米。
我们样本中的中位数与文献中引用的SP过长阈值相对应。我们的结果表明这些阈值过低，因为在50%的正常患者中都超过了这些阈值。我们建议仅当SP长度超过45毫米时才应认为其过长，45毫米对应不同性别和年龄组第90百分位数的平均值。
