An Augmented reality-based guidance system for botulinum toxin injection development and validation study

This paper presents a training-oriented AR system prototype for face-attached visualization of facial BoNT injection planning, and reports a controlled validation of its image-plane overlay accuracy and usability. The prototype was implemented on Android devices using Unity3D with ARCore face tracking. UV-aligned 2D textures encoding major facial muscle regions and procedure-specific injection-site markers were mapped onto the tracked face mesh and overlaid in real time, while a touch-based GUI provided procedural information. Accuracy was evaluated as 2D image-plane overlay error by comparing AR-indicated sites with predefined clinical reference locations under standardized capture conditions. Usability was assessed using an ISO 9241–11–based questionnaire with dental students. Under the standardized condition, the prototype achieved millimeter-level 2D overlay alignment across 12 procedures (overall mean 2D error: 1.322 ± 0.287 mm). Questionnaire responses indicated favorable perceived clarity and learnability for training-oriented use. The proposed prototype supports intuitive, face-attached visualization of BoNT planning content and demonstrates feasibility for education and pre-procedural training. The reported accuracy reflects 2D on-screen alignment and should not be interpreted as 3D anatomical accuracy. This work contributes a practical UV-texture–based AR pipeline and a validation protocol for BoNT training applications, providing a foundation for future studies incorporating 3D TRE and in-situ clinical evaluation.