Brian S Coan1, Emma Neff, Srinivasan Mukundan, Jeffrey R Marcus. 1. Durham, N.C. From the Interdisciplinary Craniofacial Imaging Laboratory; the Department of Surgery, Division of Plastic Surgery; the Department of Radiology; and the Department of Biomedical Engineering, Duke University; and CARE Plastic Surgery, P.A.
Abstract
BACKGROUND: The physiologic effects of specific rhinoplasty maneuvers are incompletely understood, largely because of a limited ability to objectively examine such interventions. The purpose of this study was to develop and validate a cadaveric model for rhinoplasty testing. METHODS: Ten cadaver heads were methodically prepared to simulate ventilatory conditions. Airway dimensions were measured with three-dimensional computed tomography and acoustic rhinometry. Airflow, pressure, and resistance were measured under conditions of both inhalation and exhalation. Resistance was determined using active anterior rhinomanometry and a continuously variable pressure gradient. Anatomic and physiologic properties were first compared against normative data. Measurements were then taken after application of an adhesive external midvault dilator (BreatheRight; GlaxoSmithKline). RESULTS: The average minimal cross-sectional areas by acoustic rhinometry and by computed tomography were 0.87 cm2 and 0.84 cm2 per nostril, respectively (n = 20). The average distance from the nostril to the internal nasal valve was 1.7 cm by acoustic rhinometry and 1.5 cm by computed tomography, consistent with published in vivo normative data at the internal nasal valve. The average resistance with simulated exhalation closely approximated known normative values. With the application of the adhesive nasal dilator, the average area (acoustic rhinometry) increased by 50 percent at the internal nasal valve. During inhalation, the resistance decreased by 21 percent following application of the adhesive dilator. CONCLUSIONS: The model provides an accurate representation of nasal anatomy and physiology suitable for objective analysis of rhinoplasty maneuvers. The objective modalities used herein may be applied to rhinoplasty study using this model with accuracy and reproducibility. The external dilator increased area at the internal valve (minimal cross-sectional area) and decreased resistance.
BACKGROUND: The physiologic effects of specific rhinoplasty maneuvers are incompletely understood, largely because of a limited ability to objectively examine such interventions. The purpose of this study was to develop and validate a cadaveric model for rhinoplasty testing. METHODS: Ten cadaver heads were methodically prepared to simulate ventilatory conditions. Airway dimensions were measured with three-dimensional computed tomography and acoustic rhinometry. Airflow, pressure, and resistance were measured under conditions of both inhalation and exhalation. Resistance was determined using active anterior rhinomanometry and a continuously variable pressure gradient. Anatomic and physiologic properties were first compared against normative data. Measurements were then taken after application of an adhesive external midvault dilator (BreatheRight; GlaxoSmithKline). RESULTS: The average minimal cross-sectional areas by acoustic rhinometry and by computed tomography were 0.87 cm2 and 0.84 cm2 per nostril, respectively (n = 20). The average distance from the nostril to the internal nasal valve was 1.7 cm by acoustic rhinometry and 1.5 cm by computed tomography, consistent with published in vivo normative data at the internal nasal valve. The average resistance with simulated exhalation closely approximated known normative values. With the application of the adhesive nasal dilator, the average area (acoustic rhinometry) increased by 50 percent at the internal nasal valve. During inhalation, the resistance decreased by 21 percent following application of the adhesive dilator. CONCLUSIONS: The model provides an accurate representation of nasal anatomy and physiology suitable for objective analysis of rhinoplasty maneuvers. The objective modalities used herein may be applied to rhinoplasty study using this model with accuracy and reproducibility. The external dilator increased area at the internal valve (minimal cross-sectional area) and decreased resistance.