PATIENT-SPECIFIC IMPLANTS FOR MANDIBULAR RECONSTRUCTION AFTER TUMOR RESECTION
Abstract
Background. Mandibular reconstruction following tumor resection is a complex challenge in oral and maxillofacial surgery. While vascularized free bone flaps remain the gold standard, 3D-printed patient-specific implants (PSIs) have emerged as a highly predictable alternative, especially when free flap harvesting is contraindicated or avoided to minimize donor-site morbidity in young patients with benign entities like ameloblastoma. However, the long-term biomechanical impact of these highly rigid alloplastic structures on the temporomandibular joint (TMJ) complex requires deeper investigation.
Objectives. This literature review aims to evaluate the clinical and surgical efficacy of custom-made alloplastic implants in post-tumor mandibular reconstruction and analyze their long-term biomechanical limitations and pathological impact on condylar unit kinematics and TMJ remodeling.
Materials and Methods. A comprehensive literature search was conducted across PubMed, Scopus, and Web of Science databases for peer-reviewed clinical studies, cohort trials, and case reports published within the last decade. The focus was restricted to 3D-printed alloplastic PSIs (titanium, PEEK) utilized after mandibular tumor ablation. Data tracking virtual surgical planning (VSP) accuracy, functional outcomes, dental occlusion stability, and TMJ remodeling or condylar displacement were extracted and subjected to a qualitative narrative synthesis.
Results. The integration of VSP and additive manufacturing (SLM titanium) reduces total operative times by 15% to 35% and provides bone segment positioning accuracy within less than 1.5 mm. Primary occlusal stability is achieved in 92% to 95% of cases. However, long-term tracking (12–24 months) reveals distinct complications driven by the stress shielding phenomenon. Highly rigid monolithic plates transfer unmitigated masticatory loads directly to the cranial base, resulting in a 20% to 35% incidence rate of TMJ dysfunction, asymmetric joint space narrowing, and progressive flattening or translation of the condylar head within the glenoid fossa.
Conclusion. While PSIs offer exceptional immediate anatomical accuracy and eliminate donor-site morbidity, their extreme structural rigidity poses a long-term risk to joint kinematics in active individuals. Future protocols must incorporate patient-specific Finite Element Analysis (FEA) during the CAD design phase and mandate early postoperative gnathological rehabilitation, including custom occlusal splints, to preserve long-term joint function and quality of life
References
1. Cusack JW. Report of the amputations of portions of the lower jaw. Dublin Hospital Reports. 1827;4:1–38.
2. Sirak SV, Sletov AA, Elizarov AV, Meboniya TT, Arutyunov AV. Reconstruction of large mandibular defects using an endoprosthesis implant. Stomatology (Mosk). 2016;95(4):45–48. (In Russ.)
3. WHO Classification of Tumours Editorial Board. Head and neck tumours. 5th ed. Lyon: International Agency for Research on Cancer; 2022. (WHO classification of tumours series; vol. 9). p. 120–128.
4. Hidalgo DA. Fibula free flap: a new method of mandible reconstruction. Plastic and Reconstructive Surgery. 1989;84(1):71–79.
5. Wong RC, Tideman H, Merkx MA, Liao K. Review of biomaterials and custom-made implants for mandibular reconstruction. Journal of Cranio-Maxillofacial Surgery. 2009;37(4):212–224.
6. Chaudhary Z, Bansal N, Joshna EK, Nehra A. Patient Specific Alloplastic Implant Reconstruction of Mandibular Defects—Safe Practice Recommendations and Guidelines. Journal of Maxillofacial and Oral Surgery. 2023;22(Suppl 1):28–36.
7. Wilde F, Hanken H, Probst F, Schramm A, Heiland M, Cornelius CP. Multicenter study on the use of patient-specific CAD/CAM reconstruction plates for mandibular reconstruction. Journal of Cranio-Maxillofacial Surgery. 2015;43(9):1858–1865.
8. Wang HW, Chang CM, Cheng Y, Lin CL. Patient-Specific Solutions for Cranial, Midface, and Mandible Reconstruction: Virtual Surgical Planning and Additive Manufacturing. Applied Sciences. 2023;13(4):2415.
9. Almudarris N, Rajput A, et al. Outcomes of Using 3D-Printed Titanium Implants in Mandibular Reconstruction. Journal of Pharmacy and Bioallied Sciences. 2025;17(Suppl 2):S1529-S1531.
10. Ramos DM, Dondani J, Arany PR. Biomechanical and biological challenges of custom alloplastic biomaterials in craniomaxillofacial reconstruction. Advanced Drug Delivery Reviews. 2022;184:114170.
11. Mascha F, Winterhalder P, Schapher M, Ristow O, Engel E, Meyer U. Clinical and biomechanical evaluation of patient-specific 3D-printed reconstruction plates for mandibular defects: A 1-year follow-up finite element analysis. Journal of Cranio-Maxillofacial Surgery. 2024;52(3):312–320.
