title: Ceratocricoid muscle: an embryological and anatomical study.
abstract: This study aimed to document the prevalence and morphology of the ceratocricoid muscle in a large sample of fetuses and adults and to explain its possible origin in a sample of embryos. Forty-five embryos, thirty-four fetuses, and ninety human larynges from adults with no known laryngeal pathology were studied. The muscle was observed in 23% of the fetal sample and in 14% of the adult sample. No significant differences were observed in the laterality in any of the groups. The ceratocricoid muscle is attached between the cricoid lamina and the inferior horn of the thyroid cartilage and also into the capsule of the cricothyroid joint. The muscle is innervated by several branches (between one and three) from the anterior division of the recurrent laryngeal nerve as it courses behind the cricothyroid joint. The ceratocricoid muscle develops from tissue within the mesenchymal bridge which connects the external and internal laryngeal sphincters or rings from embryonic stages 15-20. The close relationship of the ceratocricoid muscle to the recurrent laryngeal nerve could mean that it can exert pressure on this nerve. This may be a possible explanation for the causation of certain idiopathic recurrent laryngeal nerve palsies.
authors.affiliation: Departamento de Anatomía y Embriología Humana I, Universidad Complutense de Madrid, Madrid 08040, Spain.
authors.forename: Eva
authors.initials: E
authors.lastname: Maranillo
authors.forename: Teresa
authors.initials: T
authors.lastname: Vázquez
authors.forename: Rosa
authors.initials: R
authors.lastname: Mirapeix
authors.forename: Xavier
authors.initials: X
authors.lastname: León
authors.forename: Stephen
authors.initials: S
authors.lastname: McHanwell
authors.forename: Miquel
authors.initials: M
authors.lastname: Quer
authors.forename: José Ramón
authors.initials: JR
authors.lastname: Sañudo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003413:Cricoid Cartilage / Q000033:anatomy & histology / Q000196:embryology; D005260:Female; D005333:Fetus / Q000033:anatomy & histology / Q000196:embryology; D006801:Humans; D007823:Laryngeal Nerves / Q000033:anatomy & histology / Q000196:embryology; D007830:Larynx / Q000033:anatomy & histology* / Q000196:embryology*; D008297:Male; D008875:Middle Aged; D009132:Muscles / Q000033:anatomy & histology* / Q000196:embryology* / Q000294:innervation; D013957:Thyroid Cartilage / Q000033:anatomy & histology / Q000196:embryology; D014826:Vocal Cord Paralysis / Q000209:etiology