Pinheiro João, Cascallana José Luis, Lopez de Abajo Benito, Otero José Luis, Rodriguez-Calvo Maria Sol
National Institute of Legal Medicine and Forensic Sciences, Largo da Sé Nova, 3000 Coimbra, Portugal.
Institute of Legal Medicine of Galicia, Spain.
Forensic Sci Int. 2018 Sep;290:1-10. doi: 10.1016/j.forsciint.2018.06.019. Epub 2018 Jun 25.
The aims of this investigation were to determine the characteristics and prevalence of anatomical variants of the larynx apparatus and to evaluate the impact of these variants on the accurate diagnosis of laryngeal fractures. A population-based study was carried out, analyzing a series of 207 consecutive autopsied cases in the Institute of Legal Medicine of Galicia (Northwestern Spain). The prevalence of triticeal cartilage was 52.7% and that of agenesis of thyroid horns 10%. Calcification of the stylo-hyoid ligament accounted for 1.4%. We identified three new anatomical variants: the terminal segmentation of the thyroid horns (11.6%), ectopic superior thyroid horns (8%) and lateral thyrohyoid ossification (5.3%). These three names, based on anatomical criteria, are the author's proposal to solve the lack of uniformity in the designation of these variants. Agenesis of thyroid horns were related to the presence of ectopic superior thyroid horns in 93% of cases, either uni or bilateral. The combination of variants was present in 6.8% of the cases, being the terminal segmentation of the thyroid horns in association with triticeal cartilage the most frequent (3.8%). The probability of misdiagnosis due to the presence of anatomical variations in deaths by pressure on the neck was high in this population (71.5%). The prevalence of triticeal cartilage in more than half of the sample, determined an important rate of potential errors (46.4%), followed by the mistaken diagnoses induced by terminal segmentation of thyroid horns (7.3%) and by ectopic superior thyroid horns (6.3%). The likelihood of a misdiagnosed laryngeal fracture was greater if the thyroid cartilage was affected, with a higher proportion of false positives comparing to the hyoid bone (p<0.001). The higher frequency of thyroid fractures in neck pressure together with the prevalence and location of triticeal cartilage on the lower third of the lateral thyrohyoid ligament are the main reasons for these results. Further studies should be done with larger samples to expand epidemiological data and consolidate these results and their influence on the diagnosis of mechanical asphyxias.
本研究的目的是确定喉器官解剖变异的特征和患病率，并评估这些变异对喉骨折准确诊断的影响。开展了一项基于人群的研究，分析了西班牙西北部加利西亚法医学研究所连续207例尸检病例。麦粒软骨的患病率为52.7%，甲状腺角缺如的患病率为10%。茎突舌骨韧带钙化占1.4%。我们发现了三种新的解剖变异：甲状腺角末端节段化（11.6%）、异位上甲状腺角（8%）和外侧甲状舌骨骨化（5.3%）。基于解剖学标准，这三个名称是作者为解决这些变异命名缺乏统一性而提出的。93%的甲状腺角缺如病例与异位上甲状腺角的存在有关，可为单侧或双侧。6.8%的病例存在变异组合，其中甲状腺角末端节段化与麦粒软骨并存最为常见（3.8%）。在该人群中，因颈部受压死亡时解剖变异导致误诊的可能性很高（71.5%）。样本中超过一半存在麦粒软骨，这确定了潜在错误的重要发生率（46.4%），其次是甲状腺角末端节段化（7.3%）和异位上甲状腺角（6.3%）导致的误诊。如果甲状软骨受到影响，喉骨折误诊的可能性更大，与舌骨相比假阳性比例更高（p<0.001）。颈部受压时甲状软骨骨折频率较高，以及麦粒软骨在甲状舌骨韧带外侧下三分之一处的患病率和位置是这些结果的主要原因。应使用更大样本进行进一步研究，以扩大流行病学数据并巩固这些结果及其对机械性窒息诊断的影响。
