Benefits and Limitations of Entry-Level 3-Dimensional Printing of Maxillofacial Skeletal Models

A protocol for creating exceptionally low-cost 3-dimensional (3-D) maxillofacial skeletal models does not require proficiency with computer software or intensive labor. Small and less affluent centers can produce models with little loss in accuracy and clinical utility.

To highlight the feasibility and methods of introducing in-house, entry-level additive manufacturing (3-D printing) technology to otolaryngologic craniofacial reconstruction and to describe its clinical applications and limitations, including a comparison with available vendor models.

This case series of 6 models (3 pairs) compared cost, side-by-side anatomical model fidelity, and clinical versatility using entry-level, in-house 3-D pediatric mandible model production vs high-end, third-party vendor modeling, including a review of the literature. Comparisons were made at an urban pediatric otolaryngology practice among patients who had previously undergone pediatric craniofacial reconstruction with use of a commercially produced medical model for surgical planning. Each vendor model had been produced using computed tomographic imaging data. With the use of this same data source, in-house models were printed in polylactic acid using a commercially available printer. Data were collected from November 1 to December 30, 2015.

Models created from these 2 methods of production were assessed for fidelity of surface anatomy, resilience to manipulation and plate bending, cost of production, speed of production, sterilizability, virtual surgical planning options, and alveolar nerve canal and tooth root visibility in mandibles.

For the quantitative comparisons between in-house models (1 neonatal, 1 pediatric, and 1 adult model) and their commercial counterparts, the mean value of 7 independent measurements was analyzed from each of 3 model pairs. Caliper measurements from models produced through entry-level, in-house manufacturing were comparable to those taken from commercially produced counterparts, suggesting an acceptable degree of accuracy (0.54 mm; 95% CI, 0.36-0.72 mm). Fixed costs for in-house production included acquiring an entry-level printer (retail $2899) and an annual software subscription ($699 per year). After purchase of these initial assets, the printing cost for an in-house mandible was approximately $90, with 98% of that cost related to labor. Physical qualities of entry-level, in-house models such as nerve canal visibility, tooth root visibility, and sterilizability were inferior compared with commercially-produced stereolithic renderings.

This low-cost method of in-house, entry-level 3-D printing of straightforward, skeletal models may suit a general otolaryngology practice that performs maxillofacial reconstruction. Although commercial modeling offers several unique features, such as sterilizable materials and advanced virtual planning, in-house modeling also produces renderings with high fidelity, which may be used as tools for education and surgical planning, including preoperative plate bending.

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