Extended Complex Temporomandibular Joint Reconstructions Exploiting Virtual Surgical Planning, Navigation Assistance, and Custom-Made Prosthesis: A Comprehensive Protocol and Workflow

Abstract

Background: Alloplastic temporomandibular joint (TMJ) replacement is a well-established procedure in maxillo-facial surgery. However, the surgical management of large excision in this area requires complex reconstruction beyond the standard TMJ prosthesis. Objective: This study aims to describe the design and the consequential application of a protocol which involves the use of computer-assisted surgery tools to best face complex TMJ reconstruction (TMJR). Preoperative accurate study of every single case and intraoperative check of the surgical act are nowadays essential to perform such delicate surgical procedures. Materials and Methods: The study is a retrospective and single institution case series. The various processes of the management and planning of extended TMJ reconstruction (eTMJR) are extensively described, from the preoperative clinical evaluation, imaging acquisition protocols and virtual surgical planning (VSP), focusing also on the intraoperative transfer of VSP using navigation and surgical guides. Results: We included nine patients with different pathologies which were candidates for eTMJR. Overall, the application of our protocol and workflow permitted the reduction of complications and pain, and the improvement of the maximum interincisal opening (MIO) of the patients, restoring patients’ masticatory function and esthetics. Conclusions: The eTMJR should be considered as a safe and reliable surgical management modality in selected patients with large temporomandibular joint and skull base (TMJ-SB) lesions. An accurate preoperative protocol and workflow is essential to perform such insidious and complex reconstruction. However, more extensive studies on this type of device have to be conducted in order to validate its real usefulness and indications.

Considerations for the Use of Alloplastic Temporomandibular Joint Replacement in Irradiated Patients: Report of an Off-Label Indication

“…Diffused fibrosis, distorted neck vascularization, necessity of contralateral vascular anastomosis, and reduced bone quality may affect the procedure [8,15]. Thus, in irradiated patients further alternatives to microsurgical reconstruction are needed, and alloplastic replacements can represent a new horizon [9,17].…”

“…Progressively, bone reconstructions with alloplastic material prostheses are becoming more popular in the maxillofacial surgery field, opening new scenarios and new reconstructive alternatives [6,20]. In temporomandibular joint pathology, ATMJR has been used for the management of end-stage temporomandibular diseases for over 2 decades with success, enhancing mandibular functionality (mastication, deglutition, and phonation) and improving quality of life [9,21,22]. Because of the local inflammatory state post osteoradionecrosis, the quality of the remaining bone, and the high risk of implant exposure due to lack of skin elasticity, ATMJR may not be recommended in irradiated patients because of the higher possibility of failure and severe complications [19,23].…”

“…Because of the local inflammatory state post osteoradionecrosis, the quality of the remaining bone, and the high risk of implant exposure due to lack of skin elasticity, ATMJR may not be recommended in irradiated patients because of the higher possibility of failure and severe complications [19,23]. The introduction of virtual surgical planning for temporomandibular joint replacement has extended reconstructive opportunities, fulfilling any reconstructive need and giving the possibility to offer ATMJR in more complex patients as well [9]. Custom-made devices allow a better functional and esthetical satisfying reconstruction for the patient, improving quality of life and clinical outcomes [9,11,21].…”

“…However, when free flaps fail, a salvage reconstruction can be accomplished, with a high risk of poor and unsatisfactory results [7,8]. Alloplastic temporomandibular joint replacement (ATMJR) can offer a comprehensive solution for individuals who have undergone several surgeries and still suffer from significant functional impairment and pain [9]. This case report aims to describe a challenging case of an irradiated patient submitted to several failed mandibular reconstruction surgeries and successfully treated with an extended customized alloplastic temporomandibular joint replacement (F0M2-Higginson Classification) [10].…”

Complex Craniofacial Cases through Augmented Reality Guidance in Surgical Oncology: A Technical Report

“…Once imaging is acquired in accordance with this protocol, multiple sequences must be coregistered within a unique coordinate system both using transformational algorithms that apply normalization and difference calculations between paired images and using a reference image. This ensures that all sequences match the same anatomical localization and is a crucial step to ensure the creation of a reliable presurgical model [ 13 ].…”