A simple graded bite block for dynamic magnetic resonance imaging of the temporomandibular joint

New solutions for the dynamic assessment of the moving structures of the temporomandibular joint (TMJ), such as the intra-articular disc and the head of the mandible, are required for magnetic resonance imaging (MRI). Therefore, we propose a simple, graded bite block for dynamic MRI examination of the TMJ. The bite block consists of three main functional elements: a groove for the biting edges of the upper incisors, steps with bite surfaces for the biting edges of the lower incisors and a handle for easy placement and control of the device. The block is easily manufactured using commercially available 3D printers. The closed-mouth part of the study was performed without the bite block. The patient was instructed to place the central incisors' biting edges in the upper groove. The lower incisors' biting edges were placed consecutively on the first step, second step, and so on, in increasing order, until maximal opening was reached. Ninety-five MR examinations of TMJs were performed. The graded opening bite block was successfully applied in all but two patients. In conclusion, the simple and easy-to-use graded bite block may be a useful addition to the armamentarium of a radiologist performing MRI scans of the TMJ.