Growing lesser horn of the hyoid in human fetuses with special references to muscles attaching to it
Year: 2026
Type: article
Abstract: OBJECTIVES: The hyoid lesser horn (LH) forms a transient joint with the greater horn in human fetuses. The chondroglossus muscle attaches to the LH; however, its morphology remains unclear. We hypothesized that the muscles involved in LH accelerate joint formation. METHODS: We examined 34 human fetuses with crown-rump length of 39-230 mm. RESULTS: The LH joint was bilaterally absent in eight fetuses; the largest specimen "without" joints was 110 mm crown-rump length, whereas the smallest specimen "with" joints was 55 mm. The chondroglossus was identified as oblique muscle fibers attached to the LH medial aspect (23/34). The chondroglossus, Adjacent to the transverse lingual muscle (TLM), the chondroglossus ran supero-antero-medially to join the genioglossus. The TLM (21/34) and middle pharyngeal constrictor (pars chondropharyngica; 21/34) originated from the LH. The latter ran posteriorly from the LH medial to the hypoglossal nerve, whereas the middle constrictor arose largely from the greater horn. Notably, without LH attachment, the anterior margin of the mylohyoideus muscle (MPCM) was connected to the TLM using thick fascia wrapped around the LH. Therefore, LH disrupts the muscular ring surrounding the oropharynx. CONCLUSIONS: The variation in joint formation timing (9-16 weeks gestational age) suggests that the chondroglossus, TLM, and MPCM development do not require joint movement. Alternatively, an elongated greater horn may provide joint-like space.
Source: Journal of Oral Biosciences
Authors: Jose Francisco Rodríguez-Vázquez, Kenta Abe, Kazuma Morita, Yuki Yoshihashi, Masahito Yamamoto, Shin-ichi Abe
Language: English
Subfield: Rheumatology
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
Estimated APC paid: $2,950
OpenAlex ID: W7124166163