Page 346 - Demo

Chapter 13344could be indicated over time, due to the thinner UHMWPE part. For such reason no scaffold was provided at the interface between the skull and fossa component.(50) The mandibular component was designed in such fashion that it fitted over the resection stump of the mandible, thus preventing any potential downward, medial or lateral movement of the implant. Besides roughening the implant surface through SLA, which also improves cell attachment and proliferation,(76–80) interconnecting pores with a diameter of 600µm pores and a 80% porosity were computer-assisted designed on the bony interface of the mandibular component. The porous design allows for bone to grow inside of these void areas, improving the implant stability.(81) This extra stability, allowed for only needing 5, rather than 7, fixation screws. The position of these 5 screws is in turn dictated by the position of the inferior alveolar nerve. Also, a higher calcium deposition and higher osteocalcin and alkaline phosphate concentrations can be achieved within these pores. This phenomenon leads to better (mesenchymal) cell adhesion and elicitation of cell differentiation into osteocytes, thus improving bone formation and osseointegration.(76,82–87) As to further improve upon currently available TMJR, we aimed to retain the function of the LPM, thus allowing for laterotrusive movement. For said reason, a scaffold was designed in the condylar neck, allowing the reattachment of the LPM. By retaining the bony enthesis, together with the LPM, when performing the condylectomy, this enthesis could be threaded through a tunnel in the condylar neck and fixed against this scaffold. Lastly, as the prosthesis is custom-made, corrections for mandibular asymmetries and for jaw angle improvements could be implemented in the design immediately as well.(50) Both the ramal component and the Ti fossa component were additively manufactured using selective laser melting. This approach is not only more ecological than milling, but it also offers greater design flexibility. As a result, the intricate, patient-specific porous implant design was achievable.Nikolas de Meurechy NW.indd 344 05-06-2024 10:15