Challenges in Developing an Effective Inferior Alveolar Nerve Block Guide
The inferior alveolar nerve block (IANB) is a useful technique in dentistry, but it sometimes fails due to operator and anatomical factors, leading to complications. We aimed to create an IANB guide to enhance the safety and reliability of the IANB. Three types of IANB guides were designed for a skull model using the dentition as a fixed point and the lingula as a target point. The dentition and mandible were digitized using an intraoral scanner and computed tomography, respectively. The guides were created using a 3-dimensional printer. We assessed the accuracy, production time, material usage, and cost of the 3 guides and explored the potential clinical applications. The average error between the needle tip positions of the completed guide and the design was 0.63 mm. The average printing time was 201 minutes. The average amounts of biocompatible resin and support material used were 36 g and 52.3 g, respectively, with an average material cost of $21.60. Although the IANB guide required more time and resources than conventional IANB techniques, it exhibited suitable precision and holds promise for enhancing IANB safety and efficacy. However, its accuracy must be improved for clinical application.Objective
Methods
Results
Conclusion
Inferior Alveolar Nerve Block (IANB) Guide Creation Process
The model’s dentition and disposable syringe were converted into stereolithography (STL) data using an optical scanner, and the model’s mandible was converted into Digital Imaging and Communications in Medicine (DICOM) data using computed tomography. The obtained data were matched by computer-aided design software to design the IANB guide. The designed IANB guide was printed with a 3-dimensional (3D) printer. CAD indicates computer-aided design.
Setting the Target Point of the Inferior Alveolar Nerve Block (IANB) Guide by Computer-Aided Design Software
The 3-dimensional shape data of the mandible, dentition, and syringe were matched using computer-aided design software. We designed guides and stoppers to accurately lead the syringe to the target point. Specifically, a stopper was incorporated to ensure that the needle tip would reach 5 mm in front of the lingula, which served as the designated target point. Arrow, target point; arrowhead, lingula of the mandible.
Accuracy Verification of the Inferior Alveolar Nerve Block (IANB) Guides
We attached an IANB guide on the skull model and measured the distance from the needle tip when the syringe reached the stopper to the target point (millimeters). The measurement method involved computed tomography imaging and digitally measuring with Digital Imaging and Communications in Medicine (DICOM) data. We used the obtained DICOM data for segmentation and 3-dimensional (3D) reconstruction using medical diagnostic imaging software. Furthermore, we used computer-aided design software to superimpose images at the time of guide designing and during guide attachment on the 3D reconstructed image based on the morphology of the mandible. The safety margin was determined from the distance between the arrow and the arrowhead, and the accuracy of the IANB guide was verified from the difference between the preinsertion and postinsertion safety margins. White arrow indicates preinsertion target point; red arrow, postinsertion target point; arrowhead, lingula of the mandible. Abbreviations: CAD, computer-aided design; CT, computed tomography.
The Completed Inferior Alveolar Nerve Block (IANB) Guide
An IANB device (guide 1) printed by a 3D printer. The needle tip is pointing toward the mandibular lingula.
Contributor Notes