Benign Paroxysmal Positional Vertigo: an innovative teaching method based on a 3D-printed human labyrinth to perform diagnostic and therapeutic maneuvers

Benign paroxysmal positional vertigo (BPPV) is the most common cause of vertiginous symptoms encountered in clinical practice. It is believed to be caused by the presence in semicircular canals of detached otolithic material from the utricle and saccule; this activates the ampullary receptors and therefore leads to an incorrect perception of rotational movement. The symptoms of BPPV are by definition positional, namely evoked by specific head positions that vary depending on the side and the canal involved. The diagnostic maneuvers for all variants of BPPV rely on bringing the patients to the respective eliciting positions, while the treatment is mainly based on canalith repositioning maneuvers (CRPs), that are meant to lead the otolithic debris back to the otolithic organs. The educational approach to BPPV has been traditionally based on written material and videos, besides participating in clinical practice; some innovations in teaching BPPV have been tried, focused on either the teaching methods or creating virtual or tangible 3D models. This study intends to test a new 3D model that can be both easily accessible and faithful to reality; therefore, the model was obtained from a 3D-printed reproduction of a healthy skull and labyrinth. After having found and tested the most fitting dimensions and materials for the 3D printed model, we recreated the pathophysiology of BPPV of the posterior semicircular canal. We presented thus the model to different groups of students and medical doctors who performed the Semont and modified Epley maneuvers twice on the skull model, the first before and the second after observing the mechanics behind the disease and the maneuvers directly with the labyrinth model. Afterwards, they answered 9 questions to grade both their satisfaction and perceived knowledge after using the model, and their improvement in performing the CRPs. All three categories of participants showed a clear average improvement in carrying out the CRPs and a high rating in satisfaction and perception of improved competence. We therefore propose the 3D model both as a tool to learn the mechanics behind BPPV and as a tool for medical doctors to practice CRPs on, hopefully extending in the future the use of the model to all variants of BPPV.