Expansion hyoidplasty. 1983 First-Place Resident Research Award: clinical category.

An inspiratory, circumferential, passive collapse of the hypopharyngeal lumen is the mechanism of airway obstruction in some patients with "idiopathic" obstructive sleep apnea syndrome. While permanent tracheotomy has resolved the obstruction and reversed the associated cardiopulmonary sequelae, it is not without complications. The expansion hyoidplasty was conceived as an alternative. The hyoid bone is trisected just medial to each lesser cornu, then held in an expanded position by a permanent brace. The greater cornua with attached middle constrictor and hyoglossus are moved laterally, while the body of the hyoid with attached geniohyoid and genioglossus shifts the base of tongue anteriorly. The procedure is potentially reversible. Twenty dogs were studied before and after hyoid expansion, 10 for superior hypopharyngeal pressure-volume measurements and 10 for the closing-pressure study. Pressure-volume studies demonstrated a consistent expansion of the superior hypopharynx. Deglutition and laryngeal competence wee not grossly affected. Reexamination of four animals in the closing-pressure group 1 year postoperatively demonstrated stability of the hyoid expansion and no evidence of serious parahyoid tissue complications.