Computed tomographic study of the effect of a tongue-tie on hyoid apparatus position and nasopharyngeal dimensions in anesthetized horses

• Published in: American journal of veterinary research Vol. 62; no. 12; pp. 1865 - 1869
• Main Authors: Cornelisse, C J, Rosenstein, D S, Derksen, F J, Holcombe, S J
• Format: Journal Article
• Language: English
• Published: United States 01-12-2001
• Subjects: Anesthesia - veterinary; Animals; Horses - anatomy & histology; Horses - physiology; Hyoid Bone - anatomy & histology; Hyoid Bone - physiology; Nasopharynx - anatomy & histology; Nasopharynx - physiology; Restraint, Physical - veterinary; Statistics, Nonparametric; Tomography, X-Ray Computed - veterinary; Tongue - anatomy & histology; Tongue - physiology
• ISSN: 0002-9645
• DOI: 10.2460/ajvr.2001.62.1865

To determine the effect of manual tongue protrusion on the dimensions of the hyoid apparatus, nasopharynx, and oropharynx in anesthetized horses. tongue protrusion on the dimensions of the hyoid.
5 adult horses.
Horses were anesthetized and positioned in sternal recumbency for 2 sequential computed tomographic (CT) scans. Images were acquired with the tongue in a natural position inside the mouth. Then, the tongue was pulled rostrally and secured, and a second CT scan was performed. Dorsoventral length of the hyoid apparatus and angles of the basisphenoid, basihyoid, and ceratohyoid were measured on 3-dimensional reconstructed CT images. Cross-sectional diameters and areas of the nasopharynx and oropharynx were determined on reformatted images in the transverse and longitudinal planes, using osseous landmarks for consistency. Results were tested between the 2 groups to determine significant differences.
We were unable to detect a significant difference between any of the lengths or angles of the hyoid apparatus measured with or without rostral protrusion of the tongue. Similarly, nasopharyngeal and oropharyngeal diameters and cross-sectional areas were not significantly different with or without rostral protrusion of the tongue.
Tying the tongue rostrally out of a horse's mouth did not influence the position of the hyoid apparatus or dimensions of the nasopharynx or oropharynx in anesthetized horses. Currently, no data suggest that application of a tongue-tie is effective for maintaining stability and patency of the nasopharyngeal or orolaryngeal airways in horses during races.