Navigation-based access to the temporomandibular joint using a flexible needle: a cadaver study.

Optical navigation is a rarely used technique for puncture of the temporomandibular joint (TMJ). The flexibility of the cannula used leads to a loss of accuracy in navigated TMJ punctures. The aim of this study was to determine the accuracy of navigation-guided TMJ punctures using a flexible cannula. A navigation cone-beam computed tomography (CBCT) scan was performed to outline the puncture plan and define the trajectory in the navigation system software. After the puncture, the position of the cannula tip was documented using a further CBCT scan, and deviation from the navigation plan was determined. Thirty punctures were performed on six TMJs from three human whole-body donors. The mean deviation from the planned position of the cannula tip was 2.83 mm. The joint space was punctured successfully in 100% of cases. These findings indicate that navigation-assisted puncture is a valid and practicable procedure for puncturing the TMJ. Nevertheless, due to its higher technical demands and higher costs compared with other TMJ puncture techniques, optical navigation puncture appears to be particularly suited as an extension for complex cases or training purposes.