P-141 Development of an anatomically realistic pediatric oral- and nasal-breathing facial cast model for in vitro aerosol drug delivery studies

• Published in: Journal of aerosol medicine and pulmonary drug delivery Vol. 22; no. 2; p. 185
• Main Authors: Bosco, AP, Alfredson, T, Carpenter-Crawford, E, Cook, RO, Stenz, J
• Format: Journal Article
• Language: English
• Published: 01.06.2009
• ISSN: 1941-2711

Age-specific, anatomically realistic models are important when comparing in vitro aerosol performance measurements to in vivo deposition and clinical response. A pediatric facial cast model has been developed that incorporates a nasal airway path in addition to an oral airway path to more accurately simulate the upper respiratory tract (URT) components preceding the larynx of a pediatric patient. 3D scans of 2 and 3 year old subjects created using a Head and Face 3D Scanner (Cyberwear Inc, USA) were accessed from an existing database. Anthropological texts were consulted to determine appropriate facial landmarks to align and average the scans. Scans were orientated using these facial landmarks to create surface data and composite average scans which were imported into CAD software for manipulation and construction of the test apparatus. A soft durometer thermoplastic urethane (TPU) source (Contour Fabricators, Inc.; USA), used in prosthetic flesh construction, was obtained to provide a skin surface with realistic pliability. A rigid substrate off-set from the averaged face surface was developed to support the soft durometer TPU material while still providing realistic indention and sealing in the presence of an applied force (i.e. face mask). An interchangeable oral module was developed for both face mask and mouthpiece testing which included a nasal airway path to more accurately simulate the pre-laryngeal components of the URT. The use of this facial cast model in estimating mass output and drug delivery is currently being validated in vitro using flow-volume simulation and cascade impaction methods.