Four-dimensional computed tomographic images evaluation of change of condylar movement with and without implant-supported removable prostheses in the fibular mandible: a pilot case series report

Purpose: Although it is believed that implant-supported removable prostheses (ISrP) improve the quality of life of patients who undergo mandibular reconstruction, few studies have focused on the effect of ISrP in the fibular mandible on the function of the temporomandibular joint. This pilot case series aimed to determine whether four-dimensional computed tomography (4DCT) images allow for the evaluation of changes in condylar movements with and without ISrP. Methods: : Three patients who underwent ISrP following segmental mandibulectomy and free-flap reconstruction were evaluated. The participants were instructed to masticate a cookie during the 4DCT scan. The distance between the most anterior and posterior positions of the condyles on the sagittal view of the 4DCT images during chewing of the cookies was measured and compared with and without ISrP. Ethical approval was granted by the Medical Ethics Committee of Kobe University on 25 May, 2020 (No. B200052). Results: : Although 4DCT revealed changes in the distances of condylar protrusion with and without wearing ISrP, there were no obvious differences among the three patients. Conclusion: The 4DCT motion analysis allows for the evaluation of the effect of wearing ISrP on condylar movements during mastication in patients with mandibular reconstruction and may become a useful objective evaluation method for the functional evaluation of ISrP.