Loch Carolina, Grando Liliane J, Meurer Maria I, Zastrow Michella, Fernandes Angela, Simões-Lopes Paulo C
1 Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand.
2 Departamento de Ecologia e Zoologia, Laboratório de Mamíferos Aquáticos, Universidade Federal de Santa Catarina. Florianópolis, Santa Catarina, Brazil.
Zoolog Sci. 2017 Aug;34(4):295-299. doi: 10.2108/zs160151.
This study proposes a simple standardized method for the production of analog X-ray images of dolphin teeth, and to explore its potential use as a complementary technique in the evaluation of dental pathology in small cetaceans. We investigated exposure times that produced the best results, and whether radiographs helped in the diagnosis of macroscopic abnormalities. Teeth of six species of dolphins (Delphinidae: Tursiops truncatus, Steno bredanensis, Sotalia guianensis, Delphinus sp., Stenella coeruleoalba, and Stenella frontalis) were X-rayed in an analog dental X-ray machine operating at 70 kVp and 7 mA. Intraoral size 2 standard films were used, and the focus-film distance was standardised at 35 cm. Those species with smaller teeth (total length 12-20 mm) had the best results when exposed for 0.3 seconds, while species with larger teeth (30-45 mm) had to be exposed for 0.4 seconds for their best result. Three independent examiners analysed all the images taken. The average pairwise percent agreement was 73% (Fleiss' Kappa = 0.229), suggesting fair agreement between examiners. Analog X-ray images produced were useful in complementing the diagnosis of dental pathology and abnormalities in dolphins, in addition to allowing the observation of internal details and lesion depths, which would not be possible with conventional macroscopic methods. The use of analog X-ray imaging is easily applicable to the study of dolphin teeth, with low operating costs and simple logistics compared to other non-destructive analytical approaches such as Micro-CT.
本研究提出了一种用于制作海豚牙齿模拟X射线图像的简单标准化方法，并探索其作为评估小型鲸类动物牙齿病理学补充技术的潜在用途。我们研究了产生最佳效果的曝光时间，以及X光片是否有助于诊断宏观异常。在一台以70 kVp和7 mA运行的模拟牙科X光机中，对六种海豚（海豚科：宽吻海豚、布雷德氏海豚、圭亚那海豚、海豚属、条纹原海豚和额斑原海豚）的牙齿进行了X光检查。使用口腔内尺寸2的标准胶片，焦点-胶片距离标准化为35 cm。牙齿较小（全长12 - 20毫米）的物种在曝光0.3秒时效果最佳，而牙齿较大（30 - 45毫米）的物种则需曝光0.4秒才能获得最佳效果。三位独立的检查人员分析了所有拍摄的图像。平均两两百分比一致性为73%（Fleiss' Kappa = 0.229），表明检查人员之间的一致性尚可。除了能够观察到内部细节和病变深度（这是传统宏观方法无法做到的）之外，所产生的模拟X射线图像还可用于补充海豚牙齿病理学和异常情况的诊断。与其他非破坏性分析方法（如微型CT）相比，模拟X射线成像易于应用于海豚牙齿的研究，运营成本低且操作流程简单。
