Augmented Reality Can Improve Accuracy in Identifying Botulinum Toxin Injection Sites

Abstract

Facial botulinum toxin injection is a skill developed with experience. Inaccurate injections of the toxin can cause local complications as well as patient distress. Trainees typically learn to perform facial injections following detailed study of medical anatomy diagrams. However, anatomy diagram depictions of a ‘standard’ face may not be generalisable to the varied facial anatomy of real patients. Augmented reality (AR) technology may provide a more individualised approach. In this study, an AR smartphone app, designed for the development of recreational social media filters, was repurposed to create a face filter that overlaid facial muscles and corresponding botulinum toxin injection sites onto the face of any subject detected by the supporting device’s camera. The primary outcome was to determine if accuracy in injection site identification was superior using the AR app versus a standard facial anatomy diagram. Ten participants who were naïve to administering facial injections used both the AR app and anatomy diagram to mark 10 injection sites on the face of a test subject using a makeup pen. The distance between these sites and the ‘gold standard’ injection sites as determined by an expert botulinum toxin practitioner was calculated. Participants were more accurate with the AR app than with the diagram, with average distance from expert-identified location 4.60 mm versus 6.75 mm, respectively (p<0.01). Further research is needed in optimising this technology prior to trialling its use in patients; however, AR has tremendous potential to become a useful adjunct for procedures requiring anatomical knowledge of facial muscles.

Facial phantom model: a low-cost and safe tool for teaching botulinum toxin application in neurology residencies

“…There is also the possibility of improving the model with anatomical references to the muscles and main vessels of the face, even using resources of augmented reality previously proven successful in vivo applications. 11 A potential limitation of the static prototype is its inability to reproduce some difficulties related to in vivo application, such as moving the face during application, and, obviously, the medical-patient interaction. Additionally, the assessment of the result of the application of botulinum toxin can only be validated through the patient.…”