title: Intracordal injection technique: materials and injection site.
abstract: OBJECTIVE
  Various materials have been used for intracordal injection to treat deficiencies in glottal closure. However, specific injection sites and materials are desirable for various conditions. Here, we reviewed injection sites and materials.
  
  
  METHODS
  By considering the characteristics of injection materials used in Japan to date as well as the normal structure of the vocal cord, we have determined injection materials and sites suitable for different type of disease.
  
  
  RESULTS
  Collagen obtained commercially for injection consists mainly of type I collagen, as does autologous fascia. When this material is injected into the superficial layer of the lamina propria mucosae of the vocal cord, the wave motion of the mucosa during phonation is disturbed. This material therefore should be injected deeper into the lamina propria. Indications for collagen injection include unilateral recurrent laryngeal nerve paralysis. Even when injected into the lamina propria, fat tissue does not disturb mucosal wave motion, and is useful for treating vocal cord atrophy or sulcus vocalis.
  
  
  CONCLUSIONS
  When intracordal injection is used in vocal rehabilitation, material and site should be selected, based on the cause of glottal dysfunction.
authors.affiliation: Department of Otorhinolaryngology, Tokai University School of Medicine, Tokai University Tokyo Hospital, 1-2-5 Yoyogi, Shibuya-ku, Tokyo, Japan. otamura@tok.u-tokai.ac.jp
authors.forename: Etsuyo
authors.initials: E
authors.lastname: Tamura
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Fukuda
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Tabata
mesh_terms: D000818:Animals; D024042:Collagen Type I / Q000008:administration & dosage / Q000627:therapeutic use; D006801:Humans; D007267:Injections / Q000379:methods*; D007564:Japan; D014182:Transplantation, Autologous; D014827:Vocal Cords / Q000033:anatomy & histology / Q000473:pathology*; D014832:Voice Disorders / Q000628:therapy
chemical_list: D024042:Collagen Type I