【Introduction】
Endoscopic nasal surgery and artificial lacrimal duct insertion require a high level of anatomical structure recognition ability and operational precision. Traditional training relies on cadaver specimens or animal models, but these methods have many limitations, including limited access to specimens, insufficient anatomical variations, and ethical issues.

3D printing technology has enhanced our understanding of the mechanisms of eye diseases and the human anatomy. 3D printed models can visually present complex anatomical structures, helping students understand human anatomy and providing an economical and effective alternative for regions with limited resources. Compared with traditional cadaver models, 3D printed models are cheaper and easier to replicate, and have great application prospects in the field of medical education.

This study applied 3D printed nasal models to the training of nasal endoscopy and artificial lacrimal duct insertion, aiming to verify its educational effectiveness.

source:Li H, Li D, Sun H. Application of 3D-Printed nasal models in lacrimal surgery training. Head Face Med. 2026 Jan 2;22(1):14. doi: 10.1186/s13005-025-00579-6. PMID: 41484907; PMCID: PMC12882591.


【Materials and Methods】
Model Construction
This study collected 10 nasal CT scan images of adult patients who were treated at Beijing Tongren Hospital (slice thickness: 0.625 mm). The three-dimensional structure of the nasal cavity was reconstructed using Mimics software (version 20.0), with a focus on the nasal septum, superior turbinate, middle turbinate, inferior turbinate, uncinate process, ethmoid sinus cavity, lacrimal sac fossa, and nasolacrimal duct opening. The reconstructed tissues were converted into STL format for dissection design and printing layout, then sliced, and the color and hardness were selected.

The photopolymer resin was used (soft tissue Shore hardness 35A, bone tissue Shore hardness 60D; transmittance: 30%). The model was printed using the WJP (white inkjet printing) technology. The model retained 0.3 mm of mucosal folds and a 1.5 mm depth of the lacrimal sac fossa, and simulated intraoperative mucosal bleeding through the integrated red dye channel.

Training Design
Anatomical structure identification: Participants used a 0°/30° nasal endoscope to observe the middle turbinate, middle meatus, inferior turbinate, and inferior meatus; identify the opening of the maxillary sinus and the opening of the inferior nasolacrimal duct. Record the anatomical structure identification rate before and after training. At the same time, record the endoscopic operation time for completing this task.

Artificial lacrimal duct insertion procedure: First, the subject inserts the lacrimal probe through the upper and lower lacrimal puncta and the lacrimal canaliculus into the lacrimal sac and the nasolacrimal duct. The probe enters the lower nasolacrimal duct opening and then the lower nasal passage. Then, an artificial lacrimal duct guide wire is inserted. The guide wire is held by a nasal clamp and pulled out through the anterior nasal passage, with both ends tied.


【Results】
The Degree of Realism of the Model's Anatomical Structure
The 3D-printed nasal model constructed based on human CT data successfully replicated the complete anatomical structure of the nasal cavity and lacrimal duct system, including: the nasal tip, nasal base, nasal septum, upper, middle and lower nasal conchae, nasal passage, maxillary sinus opening, nasolacrimal duct opening, hook process, ethmoid sinus, posterior nasal aperture, etc.; at the same time, it clearly presented the degree of gasification of the middle nasal concha, the precise position of the nasolacrimal duct opening, as well as the nasopharyngeal structures such as the eustachian tube opening, pharyngeal recess, and posterior pharyngeal wall, fully meeting the anatomical detail requirements for training, providing a simulation scene close to clinical practice for trainees.

Quantitative Analysis of Training Effectiveness
All 24 trainees participated in the training. Among them, 50% had experience in endoscopic nasal/tear duct surgery, while the other 50% had less experience or no experience at all. After training with 3D printed models, the trainees' recognition rate of anatomical structures significantly improved (p < 0.0001), the time for endoscopic nasal surgery was significantly shortened (p < 0.001), and the qualification rate of tear duct implantation positioning reached 95.8% (23/24).


【Discussion】
This study explored the feasibility and effectiveness of 3D-printed nasal models in nasal endoscopy examinations and artificial lacrimal duct intubation training. The model significantly enhanced the trainees' understanding and mastery of the lacrimal duct anatomy, and received high satisfaction ratings.

Studies have shown that students who use 3D printed models perform better in anatomy tests than those who use traditional teaching methods. For instance, 3D printed heart models are particularly suitable for teaching congenital heart diseases as they can clearly display complex anatomical variations. 3D printed temporal bone models have also been proven to be more effective than traditional cadaver models, especially in demonstrating the complex structures of the outer, middle, and inner ear. Moreover, 3D printed models provide high-fidelity, reusable simulators for surgical training. 3D printed jawbone models have shown comparable effectiveness to animal models in oral surgery skills training, while avoiding ethical and cost issues.


【Conclusion】
The 3D-printed nasal model provides an efficient and cost-effective solution for training in nasal endoscopy and artificial tear duct insertion. It significantly enhances the trainees' understanding of anatomy and surgical skills. This technology is expected to become a core tool for training in otolaryngology and ophthalmology surgeries, especially in resource-poor areas and for the practice of complex surgeries.