A movable 3D printed model that demonstrates the movements of the arytenoid cartilages and vocal folds in the larynx
Authors: Nasar Rakin Tammam , Zumwalt Ann 
Published: April 2020

Breathing, swallowing, coughing, and voice production are controlled by tightly coordinated actions of intrinsic muscles of the larynx. Students report having difficulty with understanding the movements of cartilages, muscles, and vocal folds in 3D space. Cadaveric dissections have limitations to demonstrating these movements due to limited accessibility, small structures, and difficulty with simulating muscle contraction. In this project we developed a 3D printed model and used an interactive website of the larynx to teach laryngeal muscle actions as a supplement to cadaveric dissection. We hypothesized that students trained on the 3D model would perform better at solving clinical questions involving intrinsic muscles of the larynx compared to students trained using the interactive website.

The model was printed from a 3D model of the larynx created by the University of Dundee and BodyParts3D and the Database Center for Life Science https://sketchfab.com/3d‐models/anatomy‐of‐the‐larynx‐a00bc73a303c46248db6a13a88b23404. The model was assembled using the 3D printed cartilages and rubber bands which represented muscles. When a student tugs on the rubber band, the arytenoid cartilages and vocal folds move in the same action as when the muscle contracts in normal conditions. The interactive website is from Dr. Ahmet Sinav https://www1.columbia.edu/sec/itc/hs/medical/anatomy_resources/anatomy/larynx/ and shows animations of the muscle actions as well as video footage from a transnasal endoscopic procedure. One group of students was trained on the movements of the larynx using the website and the other the model. Both groups were then asked to answer clinical questions based on both the model and website.

Overall mean scores on the quiz were 90.9% for the students trained on the model (n=22) and 81.6% for the students trained on the website (n=17) a difference that was not statistically significant based on a Mann‐Whitney U test (p=0.19). Students also rated the model and the website using a 1–5 Likert scale. The students trained on the model reported mean ratings of 4.09 and 3.91 for the model and website respectively. A Wilcoxon Sign test was conducted, and the difference was not statistically significant (p= 0.32). The students trained on the model reported mean ratings of 4.33 and 3.94 for the model and website respective. A Wilcoxon Sign test was conducted and the difference was not statistically significant (p= 0.11). The majority of students (27 out of 39) reported that the lesson clarified the anatomy and/or the actions of the muscles of the larynx, regardless of learning modality. Some students reported that the lesson was a great supplement to cadaveric dissection of the larynx because not everyone could participate in the dissections simultaneously, so they could attend the lesson when they could not dissect. While the differences between the two groups were not statistically significant, both groups of students performed well on the clinical questions and they reported that the lesson was an effective supplement to the dissection.

Lateral view of the 3D printed model of the larynx with labels

Figure 1

Posterior view of the 3D printed model of the larynx with labels

Figure 2