Osseous Union after Mandible Reconstruction with Fibula Free Flap Using Manually Bent Plates vs. Patient-Specific Implants: A Retrospective Analysis of 89 Patients

Abstract

The aim of this monocentric, retrospective clinical study was to evaluate the status of osseous union in uni- and poly-segmental mandible reconstructions regarding conventional angle-stable manually bent osteosynthesis plates (Unilock 2.0 mm) versus titan laser-melted PSI patient-specific implant’s (PSI). The clinical impact of PSI’s high stiffness fixation methods on bone healing and regeneration is still not well addressed. The special interest was in evaluating the ossification of junctions between mandible and fibula and between osteotomized fibula free flap (FFF) segments. Panoramic radiograph (OPT), computed tomography (CT) scans, or cone-beam CTs (CBCT) of patients who underwent successful FFF for mandible reconstruction from January 2005 to December 2020 were analyzed. A total number of 89 cases (28 females (31.5%), 61 males (68.5%), mean age 58.2 ± 11.3 years, range: 22.8–82.7 years) fulfilled the chosen inclusion criteria for analysis (conventional: n = 44 vs. PSI: n = 45). The present study found an overall incomplete ossification (IOU) rate of 24.7% (conventional: 13.6% vs. PSI: 35.6%; p = 0.017) for mandible to fibula and intersegmental junctions. Between osteotomized FFF segments, an IOU rate of 16% was found in the PSI-group, while no IOU was recorded in the conventional group (p = 0.015). Significant differences were registered for IOU rates in poly-segmental (p = 0.041), and lateral (p = 0.016) mandibular reconstructions when PSI was used. Multivariate logistic regression analysis identified plate exposure and type of plate used as independent risk factors for IOU. Previous or adjuvant radiotherapy did not impact incomplete osseous union in the evaluated study sample. PSI is more rigid than bent mini-plates and shields functional mechanical stimuli, and is the main reason for increasing the rate of incomplete ossification. To enhance the functional stimulus for ossification it has to be discussed if patient-specific implants can be designed to be thinner, and should be divided into segmental plates. This directs chewing forces through the bone and improves physiological bone remodeling.

Segmentary Mandibular Reconstruction: A Narrative Review

“…Initially, the materials used were prefabricated, that is, titanium plates that were molded by surgeons during surgical procedures. These procedures are still widely used, but they can present failures such as bone fracture, infection, graft nutrition failure, material displacement or skin exposure depending on the extent of the bone defect ( AWAD, 2019;KAKARALA, 2018;KNITSCHKE et al, 2022;HIDALGO, 1989;KOKOSIS et al, 2016;LANDAU et al, 2018;HOUDEK et al, 2017;ROSSON;NAVIN et al, 2005;VINCENT;MARC, 2021). The thickness of the material does not allow adequate bone contouring and may leave aesthetic sequelae.…”

“…The thickness of the material does not allow adequate bone contouring and may leave aesthetic sequelae. In addition, it does not allow masticatory rehabilitation of the mandible, as it does not rebuild the alveolar ridge so that dental prostheses can be adapted or implants installed (KNITSCHKE et al, 2022;RACHMIEL et al, 2017;KOKOSIS et al, 2016). An alternative used to solve these problems is the association of bone grafts to plates, usually from the iliac crest, tibia, fibula, scapula or skullcap, and, depending on the extent of the grafts, it is necessary to obtain them in a vascularized form to maintain the nutrition of transported tissue ( AWAD, 2019;HIDALGO, 1989;VINCENT;MARC, 2021).…”

“…An alternative used to solve these problems is the association of bone grafts to plates, usually from the iliac crest, tibia, fibula, scapula or skullcap, and, depending on the extent of the grafts, it is necessary to obtain them in a vascularized form to maintain the nutrition of transported tissue ( AWAD, 2019;HIDALGO, 1989;VINCENT;MARC, 2021). Currently, the vascularized grafts of the tibia are the most performed due to the volume and similarity with the body of the mandible, facilitating, in a way, the modeling of the graft and adaptation to the recipient bone, as well as the installation of dental implants for future masticatory rehabilitation (AWAD)., 2019;KAKARALA, 2018;KNITSCHKE et al, 2022;HIDALGO, 1989;KOKOSIS et al, 2016;LANDAU et al, 2018;HOUDEK et al, 2017;ROSSON;NAVIN et al, 2005;VINCENT;MARC, 2021). Even so, the technique depends on a specialized medical team and specific equipment to perform the procedure, often available only in large centers.…”

“…Free grafts, vascularized or not, have been the main form of functional and aesthetic rehabilitation of patients affected by trauma, tumors, congenital or acquired deformities or infections (WAD, 2019;KAKARALA, 2018). Even so, the morbidities of patients undergoing this treatment associated with the risk of contamination offered by the oral microbiota and the total time for final rehabilitation makes new techniques to be developed (BARR et al, 2020;KNITSCHKE et al, 2022). The state of the art in mandibular reconstructions concerns the use of titanium metallic prostheses (MOIDUDDIN et al, 2019;LEE et al, 2018;MOVAHED et al, 2015).…”

Quantitative Assessment of the Restoration of Original Anatomy after 3D Virtual Reduction of Long Bone Fractures

“…Purpose of fracture treatment is to achieve the union of the bone fragments [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 ]. Moreover, it is to restore the function of the musculoskeletal system and prevent future complications associated with the failure of restoration of the normal anatomy [ 10 , 11 , 12 , 13 ]. The reduction of a fracture is the process of reconstructing the fractured bone by relocating the pieces of the fractured bones in their original positions [ 14 , 15 , 16 , 17 ].…”