title: Reliability of ultrasound evaluation of hyoid-larynx approximation with positional change.
abstract: We evaluated the reliability of ultrasound evaluation of hyoid-larynx approximation with positional change. Twenty healthy volunteers (10 men, 10 women) participated in this study. The distance between the hyoid bone and thyroid cartilage was measured by ultrasound in both the sitting and supine positions. Hyoid-larynx approximation was defined as the shortest distance between the lower tip of the hyoid bone and the upper end of the thyroid cartilage during swallowing. The transducer was placed in a longitudinal position above the midline of the larynx, which allowed visualization of the hyoid bone and thyroid cartilage. Patients were given 5 mL of water and swallowed. The measurement was repeated three times to enable averaging in each position. Using the mean distance at rest and the shortest distance during swallowing, we calculated relative laryngeal elevation. There was no significant difference in resting distance between the hyoid bone and thyroid cartilage with positional change or gender, with identical relative laryngeal elevation. However, there was a negative correlation between the resting and approximation distance and body mass index. In conclusion, ultrasound evaluation in healthy volunteers revealed no difference in hyoid-laryngeal approximation on swallowing in either the supine or sitting position. This finding is likely to be of value in the investigation of dysphagia.
authors.affiliation: Department of Rehabilitation Medicine, Chungnam National University Hospital, School of Medicine, Chungnam National University, Daejeon, South Korea.
authors.forename: So Young
authors.initials: SY
authors.lastname: Ahn
authors.affiliation: Department of Rehabilitation Medicine, Chungnam National University Hospital, School of Medicine, Chungnam National University, Daejeon, South Korea.
authors.forename: Kang Hee
authors.initials: KH
authors.lastname: Cho
authors.affiliation: Department of Rehabilitation Medicine, Chungnam National University Hospital, School of Medicine, Chungnam National University, Daejeon, South Korea.
authors.forename: Jaewon
authors.initials: J
authors.lastname: Beom
authors.affiliation: Korean Food Research Institue, 516 Baekhyun-Dong, Bundang-Ku, Songnam-Si, Kyunggi-Do 463-746, Republic of Korea.
authors.forename: Dong Jun
authors.initials: DJ
authors.lastname: Park
authors.affiliation: Department of Rehabilitation Medicine, Chungnam National University Hospital, School of Medicine, Chungnam National University, Daejeon, South Korea. Electronic address: Drjeesungju@cnuh.co.kr.
authors.forename: Sungju
authors.initials: S
authors.lastname: Jee
authors.affiliation: Department of Rehabilitation Medicine, Chungnam National University Hospital, School of Medicine, Chungnam National University, Daejeon, South Korea.
authors.forename: Jin Hee
authors.initials: JH
authors.lastname: Nam
mesh_terms: D000328:Adult; D059925:Anatomic Landmarks / Q000000981:diagnostic imaging; D003679:Deglutition / Q000502:physiology*; D005260:Female; D006801:Humans; D006928:Hyoid Bone / Q000000981:diagnostic imaging* / Q000502:physiology; D007089:Image Enhancement / Q000379:methods; D007830:Larynx / Q000000981:diagnostic imaging* / Q000502:physiology; D008297:Male; D056888:Patient Positioning / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014463:Ultrasonography / Q000379:methods*
keywords: Dysphagia; Hyoid–larynx approximation; Positional change; Ultrasound