Raja Gnanadev,1 Joe Iwanaga,2 Marios Loukas,3 and also R. Shane Tubbs4
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The hyoid contributes to plenty of biomechanical processes consisting of swallowing. Additionally, the hyoid bone has actually been studied for over a century in an initiative to catalog and categorize many observed biometric differences. This has actually led to the hyoid being a major structure connected in forensic pathology. In this paper, we talk about a an extremely unusual finding of an adult female hyoid bone.
The hyoid bone is a distinct structure in the human being body for plenty of reasons. The larynx is really cartilaginous area, other than for the sole regional bony structure—the hyoid bone. Famously, the hyoid bone is the just bone in people that does not articulate with any other bone, however only has actually muscular, ligamentous, and also cartilaginous attachments. Provided this peculiarity, it has been defined as “free floating” <1>.
Given the the vast number of muscles is attached come the hyoid, that is no surprise that the hyoid bone contributes to actions such together mastication and also swallowing. Additionally, variations in morphometric data between the sexes have actually been well studied and have had a strong contribution come forensic medicine for decades <2-3>.
Herein, we report an unusual variation of the hyoid bone and also briefly testimonial morphometric researches on hyoid bone anatomy.
During the routine dissection the the head and also neck of one adult mrs Caucasian fresh frozen cadaver, an inexplicable morphology of the hyoid bone was observed. The sternohyoid and also omohyoid muscles room attached come the lower border that the hyoid body together usual. The hyoid bone to be resected indigenous the anterior neck and also the soft tissues on the bone to be removed. The elevation of the body of the hyoid bone then was uncovered to be larger than normal and measured 15.9 mm (Figure 1). However, the greater cornu and also lesser cornu were found to be normal in size and orientation. The worse edge the the human body of the bone was attracted out and presented with an unexplained edge at the website of attachment of the omohyoid and also sternohyoid muscles. No vault scars or proof of trauma was discovered in this specimen in the region dissection. Additionally, no various other anatomical variations to be noted.
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Measurement of the variant hyoid bone.
The hyoid bone is situated inferior come the mandible, and superior to the thyroid cartilage in ~ the level the the third cervical vertebra in the midline. Laryngeal muscles connect on the superior body, inferior body, and also laterally follow me the every of the horns. Embryologically, the cartilage of the 2nd pharyngeal (hyoid) arch creates the lesser horn and that the the third pharyngeal arch offers rise come the greater horn. The ventral side of the 2nd and third pharyngeal arcs fuses to kind the body of the hyoid bone throughout the 4th week the gestation.
This report focuses on the inferior part of the hyoid body wherein the omohyoid and sternohyoid muscle attach. One elongated human body (15.9 mm) along this inferior edge was noted in the specimen.
Many researchers have investigated the sex dimorphism observed regarding the hyoid bone and also the variation appears to it is in consistent across many measurements. These variations encompass angles that measurement from the body to the greater and also lesser tubercles, size of the horns, and also thickness of the body, amongst many others <1-3>. By cataloging this variations, forensic pathologists have been able to use hyoid bone morphology v relatively great accuracy to make determinations related to identifying the deceased <3>. Given the meaning of being able to do this, a relatively complicated categorization system has been occurred for various known shapes of the hyoid. Remarkably, it has been noted that 60% that hyoid skeletal still do not fit right into one of these commonly described categories <4>.
Unfortunately, over there are couple of studies that have analyzed the street from the superior border come the worse border of the body. A search of the literature has yielded just two studies, be separate by over a century, through metrics ~ above this measurement of the hyoid. In 1909, Parsons analyzed the hyoid bone from 108 adult cadavers native male adults (53), female adult (28), and children (27). His results verified an average elevation of 1.2 centimeter for males (range: 1.0-1.6 cm), and 1.0 centimeter for females (range: 0.9-1.2 cm) <5>. In 2012, a team of Japanese researchers analyzed 600 hyoid bones (310 males, 290 females) making use of three-dimensional computed tomography (CT) imaging. Your data closely matched the of the 1909 study mirroring a mean height of 9.4 mm in males (range: 6.3-16.0 mm), and also 7.8 mm in females (range: 3.0-8.8 mm) <6>. However, the specific morphology the the hyoid bone in these situations was no reported.
Finally, there are reported situations of ossification the the muscle that attach to the hyoid bone, e.g., traumatic and genetic myositis ossificans <7>. A evaluation of the literature yielded a single case report ~ above traumatic myositis ossificans in the exceptional belly the the omohyoid. In this case, the ossification to be unilateral, palpable on physical examination, and plainly visible top top radiographs <8>.
Anatomical sports such together the one explained herein, can an outcome in dorn level surgery as the usually positioned and also sized hyoid bone is provided by operated doctor to calculation the C3 vertebral level <9-12>. Furthermore, as the anterior neck is frequently palpated during physical examination, bony variants such as the one explained here could lead come misdiagnosis or at least, unnecessary testing.
The hyoid bone has actually both many unique anatomical features and also clinical relevance in forensic pathology. Therefore, reports that hyoid bone sports are important to anatomists and also clinicians alike.
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