Development of handheld optical coherence tomography based on commercial intra-oral scanner for extended clinical utility in dentistry

The main objective of this study is to develop a handheld dental optical coherence tomography (OCT) system capable of imaging the target area of the teeth in the oral cavity and demonstrate the applicability of the developed system to in vivo dental disease diagnosis based on a user-friendly scanner form. The design of the developed system is based on mimicking the shape of a commonly used commercial intra-oral scanner (IOS) so that the system users do not feel awkward when using it. A microelectromechanical system (MEMS) scanning unit was used to optimize the overall size of the system, and the optical axis was designed in a Z-shape to maximize the beam size reflected by the MEMS mirror. A pre-study of in vivo oral scanning was performed to demonstrate the enhanced clinical feasibility of the developed system. Furthermore, the main experiment classified teeth with worn cervical regions into two groups according to the cervical abrasion shape. The developed dental OCT system produced a three-dimensional image of the scanning area and quantitatively analyzed the margin gap through an A-scan profile based on cross-sectional images. This study confirms the effectiveness of the developed handheld dental OCT system in actual dental clinical practice, and we expect our system to be utilized for various dental diseases, not only for diagnosing and cervical abrasions.