Background: Alloplastic temporomandibular joint (TMJ) replacement is a well-recognized technique. However, handling significant excision in this region necessitates reconstructive steps that go beyond the typical TMJ prosthesis. Objective: This study evaluates the results of standard and extended total temporomandibular joint replacement (eTMJR) using customized prostheses and computer-assisted surgery tools to address difficult TMJ reconstruction (TMJR). Materials and Methods: The study is a retrospective case series including two institutions. Extended TMJ reconstruction (eTMJR) management and planning procedures are thoroughly explained, including preoperative clinical evaluation, imaging acquisition techniques, and virtual surgical planning (VSP). Results: We included ten patients with different pathologies who were candidates for eTMJR, with a focus on both functional restoration and aesthetic rehabilitation. Overall, the application of our protocol and workflow permitted the reduction of complications and pain, restoring patients' masticatory function and esthetics. We analyzed Maximum Interincisal Opening (MIO) and Visual Analog Scale (VAS) scores preoperatively and at follow-up. Our findings show significant improvements in MIO and pain reduction, consistent with previous studies using virtual surgical planning (VSP) and 3D-printed custom prostheses. Conclusions: For certain patients with significant temporomandibular joint and skull base (TMJ-SB) lesions, the eTMJR should be regarded as a secure and reliable surgical therapeutic technique. To carry out such subtle and intricate rebuilding, a precise preoperative procedure and workflow are necessary. This study underscores the importance of personalized treatment plans for TMJ reconstruction and highlights the efficacy of eTMJR in improving both occlusal function and quality of life.