Morphogenesis of the second pharyngeal arch cartilage (Reichert's cartilage) in human embryos

Abstract

This study was performed on 50 human embryos and fetuses between 7 and 17 weeks of development. Reichert's cartilage is formed in the second pharyngeal arch in two segments. The longer cranial or styloid segment is continuous with the otic capsule; its inferior end is angulated and is situated very close to the oropharynx. The smaller caudal segment is in contact with the body and greater horn of the hyoid cartilaginous structure. No cartilage forms between these segments. The persistent angulation of the inferior end of the cranial or styloid segment of Reichert's cartilage and its important neurovascular relationships may help explain the symptomatology of Eagle's syndrome.

The Origin of the Variations of the Hyoid Apparatus in Human

“…We did not observe a clear asymmetric development of the HA, even the found angulations of RC were bilateral, as in previous paper by Rodrıguez-Vazquez et al (2006). Alpoz et al (2014) noted that there was statistically no significant influence of gender on the symmetry of the styloid chain complex.…”

Unilateral complete articulated ossification and aberrant thickening of the stylohyoid chain

“…The styloid segment (cranial part) was attached superiorly to the skull base whereas the hyoid segment (caudal part) was attached inferiorly to the body and greater horn of the hyoid cartilaginous structure. No cartilage had formed between these two segments except for one specimen in which a continuous cartilaginous structure was evident unilaterally (8). This unique variation and the theory that the styloid process continues to ossify slowly into adulthood may explain the complete ossification of the stylohyoid chain (2,6,(8)(9)(10).…”

Calcificación del ligamento estilohiodeo y apófisis estiloides elongada: hallazgo durante una necropsia médico legal por muerte súbita

“…Su longitud puede variar desde 2 a 3 cm [11][12][13] y hasta 8 cm en algunos reportes [6,7]. Sirve como punto de origen para los músculos estilohioideo, estilogloso y estilofaríngeo, y para los ligamentos estilohioideo y estilomandibular; además, se encuentra contiguo a las arterias carótida externa e interna en relación con los barorreceptores y el plexo perivascular carotídeo [4,5] El ligamento estilohioideo se extiende desde la porción distal de la apófisis estiloides hacia el asta menor del hueso hioides, y a diferencia de la apófi-sis estiloides, su remanente distal, de características fibrosas, puede presentar posibilidad de osificación [1,4,5,[9][10][11][12][13].…”