Laryngeal anatomical variants and their impact on the diagnosis of mechanical asphyxias by neck pressure

Triticeal cartilage: a meta-analysis of prevalence and morphologic evaluation

PURPOSE

The triticeal cartilage, situated within the lateral thyrohyoid membrane, remains elusive in function yet crucial in clinical contexts. Composed of hyaline cartilage, it is prone to ossification, potentially leading to diagnostic challenges such as misidentification with atherosclerosis or fractures.

METHODS

This study, aiming to establish its prevalence and highlight clinical relevance, conducted a systematic review across several electronic databases such as Medline, PUBMED, Scopus, Google Scholar, Web of Science, SpringerLink and Sciencedirect using keywords "triticeal cartilage", "triticeous cartilage" or "cartilago triticea". An assurance tool for anatomical investigations was used to assess the quality of the methodology (AQUA). A random effects model was utilized to determine the pooled prevalence.

RESULTS

The true prevalence of triticeal cartilage was found to be variable, with an overall pooled proportion of 43% while crude prevalence were 50.6%. Its crude prevalence was notably higher in women compared to men, in contrary true prevalence was higher in men, posing sex-related disparities. It was mostly seen bilaterally. When the morphologic characteristics of the cartilage were evaluated, classification differences were observed in terms of shape, with a mean length of 5.48 mm, a mean width of 3.04 mm and a mean weight of 62.32 mg. The vertebral level at which the TC was located was mostly C4. The degree of calcification of the cartilage was most commonly mild.

CONCLUSION

In conclusion, triticeal cartilage holds significant clinical importance, necessitating vigilance during diagnostic evaluations and surgical approaches. Further studies are imperative to elucidate its function comprehensively and refine diagnostic strategies, ensuring optimal patient care in neck-related pathologies.

Investigation of triticeal cartilage anatomy in forensic autopsy cases

PURPOSE

This study aims to determine the presence and morphology of triticeal cartilage (TrC) through autopsy cases and to examine its relationship with age, gender, and height, thus contributing to clinical practices and forensic perspective.

MATERIALS AND METHODS

 Our study was conducted on a total of 84 autopsy cases between the ages of 20-90 years who came to Tokat Forensic Medicine Institute. The laryngeal region was palpated to determine whether TrC was present. The dimensions of the TrC and the length of the upper horn of thyroid cartilage (UHThC) were measured with precise digital calipers, and its weight was measured with an accurate digital scale.

RESULTS

The presence of TrC was identified in 56% of the autopsy cases examined. The prevalence of TrC was higher in males (61.9%) than in females (23.1%). It was determined to be bilateral in 45% of the cases and unilateral in 11%. TrCs had a cylindrical shape in 68.2%, an oval shape in 25.8%, and a pyramidal shape in 5.8%. The average weight of TrC was 67.93 ± 33.91 mg on the right side and 72.67 ± 32.23 mg on the left. As the individual's height increased, the weight of TrC increased (p < 0.001). Additionally, there was a strong positive correlation between the lengths of TrC and UHThC and the individual's height (p < 0.001).

CONCLUSION

TrC may be confused with UHThC fractures. Therefore, we believe that knowledge of the presence and morphology of TrC will contribute to clinical approaches and forensic cases, especially in relation to the neck region.

Post-pubertal developmental trajectories of laryngeal shape and size in humans

Laryngeal morphotypes have been hypothesized related to both phonation and to laryngeal pathologies. Morphotypes have not been validated or demonstrated quantitatively and sources of shape and size variation are incompletely understood but are critical for the explanation of behavioral changes (e.g., changes of physical properties of a voice) and for therapeutic approaches to the larynx. This is the first study to take this crucial step and results are likely to have implications for surgeons and speech language pathologists. A stratified human sample was interrogated for phenotypic variation of the vocal organ. First, computed tomography image stacks were used to generate three-dimensional reconstructions of the thyroid cartilage. Then cartilage shapes were quantified using multivariate statistical analysis of high dimensional shape data from margins and surfaces of the thyroid cartilage. The effects of sex, age, body mass index (BMI) and body height on size and shape differences were analyzed. We found that sex, age, BMI and the age-sex interaction showed significant effects on the mixed sex sample. Among males, only age showed a strong effect. The thyroid cartilage increased in overall size, and the angulation between left and right lamina decreased in older males. Age, BMI and the age-height interaction were statistically significant factors within females. The angulation between left and right lamina increased in older females and was smaller in females with greater BMI. A cluster analysis confirmed the strong age effect on larynx shape in males and a complex interaction between the age, BMI and height variables in the female sample. The investigation demonstrated that age and BMI, two risk factors in a range of clinical conditions, are associated with shape and size variation of the human larynx. The effects influence shape differently in female and male larynges. The male-female shape dichotomy is partly size-dependent but predominantly size-independent.

Anthropological analysis of trauma in throat bone and cartilage: A review

In their analysis of recovered human remains, forensic anthropologists encounter structures of the throat (hyoid bone, thyroid cartilage/bone, cricoid cartilage/bone) that may present evidence of trauma. The recent published literature provides guidelines for the detection and interpretation of fractures in these tissues. Such traumatic injury frequently is associated with victims of hanging and strangulation, but many other causes have been recognized. Although the hyoid is not always recovered in skeletonized remains, it can reveal evidence of perimortem trauma and must be interpreted appropriately.

Unilateral and bilateral agenesis of the upper thyroid horns - A morphometric analysis of the larynx

The agenesis of one or both upper thyroid horns (UTH) cannot be considered rare with an incidence ranging between 0.8-9.4%. Studies so far have mostly described frequencies, yet surveys on its morphology and traumatology are missing. It is unknown to what extent this anatomical variant impacts the overall symmetry of the larynx. For the trauma reconstruction after cervical trauma this knowledge is required as an asymmetric larynx can show a different fracture pattern. In this investigation, larynxes with unilateral (n=21)/bilateral (n=5) agenesis of the upper thyroid horn(s) and a control group with regular larynxes (n=23) were juxtaposed. Various measurements were taken after μ-CT scanning. In total 10 distances/angles for the thyroid cartilage and 8 for the cricoid cartilage were compared. Using intra-individual and matched pair comparisons the symmetry was assessed. The results of this investigation showed significant differences in the intra-individual and pairwise comparison for the opening angle and the length of the thyroid alae although the lateral inclination of the thyroid alae showed no significant difference. Combining these three parameters into one symmetry score, the comparison was not significant. This research demonstrates that neither unilateral nor bilateral agenesis of the UTH is related to a structural disbalance of the larynx. Thus, different fracture patterns or vulnerabilities are not to be expected.

Symmetrical Apophyses on the Posterior Margins of the Thyroid Cartilage: A Previously Undescribed Anatomical Variation With Potential Forensic Implications

Differential diagnosis between normal/variant anatomy and pathological/traumatic findings represents one of the main matters of investigation of the so-called forensic clinical anatomy. In the literature, many anatomical variations of the laryngeal thyroid cartilage have been reported, with potential implications in forensic pathology. They include triticeal cartilages, foramen thyroideum, asymmetry, segmentation or agenesis of the superior thyroid horns, bone connections with the hyoid bone, absence of cricothyroid facets, hypertrophy of the inferior thyroid tubercle, and asymmetries in the thyroid notch, isthmus, or length of the inferior horn. In this report, we describe a laryngeal anatomical variation never described before, consisting of 2 apophyses symmetrically arising from the posterior margins of the thyroid laminae. Postmortem computed tomography performed on the laryngeal visceral block excluded previous traumatic injuries or natural pathologies of the laryngeal cartilages, confirming the congenital origin of the finding. An "omega epiglottis" and 3 laryngeal cysts in the piriform sinuses also coexisted, suggesting the possibility of underlying common developmental mechanisms.