Use of the 2.0-mm Locking Reconstruction Plate in Primary Oromandibular Reconstruction after Composite Resection

Titanium Alloy Implants with Lattice Structures for Mandibular Reconstruction

In recent years, the field of mandibular reconstruction has made great strides in terms of hardware innovations and their clinical applications. There has been considerable interest in using computer-aided design, finite element modelling, and additive manufacturing techniques to build patient-specific surgical implants. Moreover, lattice implants can mimic mandibular bone's mechanical and structural properties. This article reviews current approaches for mandibular reconstruction, their applications, and their drawbacks. Then, we discuss the potential of mandibular devices with lattice structures, their development and applications, and the challenges for their use in clinical settings.

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

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.

Fibula free flap in maxillomandibular reconstruction. Factors related to osteosynthesis plates' complications

The aim of this paper is to identify risk factors associated with the development of osteosynthesis plates' related complications in fibula free flap reconstructions. This is a case series study of consecutive fibula free flaps. Clinical and radiological variables were recorded. Patient outcomes were evaluated with special attention to osteosynthesis plates' related complications; these included plate exposure, plate fracture, loosening of screws, non-union, bone resorption, oro-cutaneous fistulas, and bone exposure. We have done a descriptive analysis, univariate analysis, and multivariate logistic regression model to explore possible risk factors for osteosynthesis plates' related complications. Data analysis was performed using R software (version 3.5.0). 111 fibula free flaps were studied. 29 patients (26.1%) developed osteosynthesis plates' related complications. The mean time to osteosynthesis plates' related complications was 22 months; range (1-120); the median and mode were 12 months. Patients with preoperative radiotherapy (34% vs 14%, p = 0.021), and secondary reconstruction (31% vs 15%, p = 0.053) had a higher incidence of osteosynthesis plates' related complications. In the univariate analysis, "preoperative radiotherapy" (OR 3.07, 95%CI = 1.139-8.242, p = 0.025) and "extraoral soft-tissue defect" (OR 2.907, 95%CI = 1.032-8.088, p = 0.042) were risk factors for osteosynthesis plates' related complications. We have observed an interaction effect: patients with mandibular Brown's classes III + IV and "secondary reconstruction" have a higher risk for osteosynthesis plates' related complications; more than 47.30 times compared to Brown's class I and "primary reconstruction" (p = 0.026). Different factors may contribute to the development of osteosynthesis plates' related complications. Our study adds important information about these. Patients with higher risk of developing complications should be informed that a second intervention to remove the plates might be necessary.

The use of vascularized fibula flap in mandibular reconstruction; A comprehensive systematic review and meta-analysis of the observational studies

BACKGROUND

Vascularized fibular flaps are considered the gold standard for the reconstruction of segmental defects in the mandible. This review compares the complication and success rates of these techniques between primary and secondary reconstruction, as well as between lateral and antero-lateral defects.

TYPE OF STUDIES REVIEWED

A systematic review and meta-analysis were conducted according to PRISMA protocol and the Cochrane Handbook for Systematic Reviews of Interventions. The authors performed an independent comprehensive search using PubMed, Ovid MEDLINE, Web of Science, the Cochrane Central Register of Controlled Trials, ClinicalTrials.gov and COS Conference Papers Index according to established inclusion and exclusion criteria. The methodological index for nonrandomized studies (MINORS) was used to assess the quality of the included studies. Meta-analysis was conducted to compare the type of reconstruction and location of the defect.

RESULTS

Seventy-eight studies, involving 2461 patients, were eligible. 83.7% of the included patient received primary reconstruction with vascularized fibular flap. The overall flap success rate was 93%. There was improvement in MINORS quality score over time with positive correlation with the publication year (r = 0.5549, P < 0.0001, CI 0.3693 to 0.6979). Meta-analysis indicated no significant association in flap success between primary and secondary reconstruction, or lateral and antero-lateral defects.

CONCLUSION

Based on the available studies, this review found no evidence of difference in success or complication rates between primary and secondary reconstruction or between lateral and anterolateral defects. High-quality clinical studies are required to analyze the outcome of these techniques, especially regarding the impact of chemotherapy, radiation therapy, implant-supported dental prostheses, and preoperative planning, on the outcome of reconstruction.

Customized mandibular reconstruction plates improve mechanical performance in a mandibular reconstruction model

The purpose of this paper was to analyze the biomechanical performance of customized mandibular reconstruction plates with optimized strength. The best locations for increasing bar widths were determined with a sensitivity analysis. Standard and customized plates were mounted on mandible models and mechanically tested. Maximum stress in the plate could be reduced from 573 to 393 MPa (−31%) by increasing bar widths. The median fatigue limit was significantly greater (p < 0.001) for customized plates (650 ± 27 N) than for standard plates (475 ± 27 N). Increasing bar widths at case-specific locations was an effective strategy for increasing plate fatigue performance.

Evaluation of plate-related complications and efficacy in fibula free flap mandibular reconstruction

AIM

The objective of this study was to evaluate the incidence of plate-related complications after vascularized bony reconstruction of the mandible, comparing the plate type used.

PATIENTS AND METHODS

Between 2004 and December 2012, a total of 41 free osteocutaneous fibula flaps have been used in an equal number of patients for reconstruction of the mandible, at the Division of Maxillofacial surgery, San Giovanni Battista Hospital, University of Turin. Malignant pathology was the most common indication for segmental mandibulectomy.Patient outcomes were retrospectively evaluated with special attention to plate complications such as plate fracture, exposure, infection, and bony nonunion.The types of reconstruction plates used were mandible plates 2.0, locking plates 2.0, miniplates (<2.0), and locking 2.4 plates.

RESULTS

Mandible plates 2.0 were used in 14 patients, locking plates 2.0 in 12 patients, and locking 2.4 plates in 4 patients. The most commonly used plates were miniplates, which were used in 86 patients.A total of 5 plate complications occurred after 41 procedures in an equal number of patients.Two complications occurred in patients receiving 2.0 mandible plates (2/14). One complication occurred in patients receiving 2.0 locking plates (1/12). Two complications occurred in patients receiving miniplates (2/86).

CONCLUSIONS

In our experience, miniplates are not associated to a high rate of complications comparing to other plates. The advantage of these plates and the low rate of complications make them our first choice for mandibular reconstructions.

Comparative evaluation of bite forces in patients after treatment of mandibular fractures with miniplate osteosynthesis and internal locking miniplate osteosynthesis

Aims and Objectives:

The aim of present study was to compare the stability of fractured mandibular fragments under functional load, when fixed with conventional miniplate and internal locking miniplate.

Materials and Methods:

Bite force (in kg) recorded in twenty mandible fractured patients and fifty normal healthy individuals. Bite force was measured at incisor and molar regions. Comparative evaluation of bite force generated was performed between 10 cases treated with conventional miniplates and 10 cases treated with internal locking miniplates. Bite force generated by patients in mandibular fracture between symphysis and the angle of mandible was recorded in incisor and molar regions preoperatively. The fracture fragments were fixed using the above fixation techniques. Then same recording was undertaken on the 7^th, 14^th, 21^st, 28^th, and 90^th days postoperatively.

Results:

Bite force generated by patients treated with locking plates at the 7^th, 14^th, 21^st, 28^th, and 90^th postoperative days was significantly higher as compared to those in patients treated with miniplates.

Conclusion:

It was observed in our study that the locking plate/screw system offers significant advantages over the conventional plating system. There are no intraoperative difficulties associated with placement of the plate.

Hardware removal after osseous free flap reconstruction

OBJECTIVE

Identifying risk factors for hardware removal in patients undergoing mandibular reconstruction with vascularized osseous free flaps remains a challenge. The purpose of this study is to identify potential risk factors, including osteocutaneous radial forearm versus fibular flap, for need for removal and to describe the fate of implanted hardware.

STUDY DESIGN

Case series with chart review Setting Academic tertiary care medical center.

SUBJECTS AND METHODS

Two hundred thirteen patients undergoing 227 vascularized osseous mandibular reconstructions between the years 2004 and 2012. Data were compiled through a manual chart review, and patients incurring hardware removals were identified.

RESULTS

Thirty-four of 213 evaluable vascularized osseous free flaps (16%) underwent surgical removal of hardware. The average length of time to removal was 16.2 months (median 10 months), with the majority of removals occurring within the first year. Osteocutaneous radial forearm free flaps (OCRFFF) incurred a slightly higher percentage of hardware removals (9.9%) compared to fibula flaps (6.1%). Partial removal was performed in 8 of 34 cases, and approximately 38% of these required additional surgery for removal.

CONCLUSION

Hardware removal was associated with continued tobacco use after mandibular reconstruction (P = .03). Removal of the supporting hardware most commonly occurs from infection or exposure in the first year. In the majority of cases the bone is well healed and the problem resolves with removal.

Efficacy of small reconstruction plates in vascularized bone graft mandibular reconstruction

BACKGROUND

Utilization of vascularized bone grafts rigidly fixated with titanium reconstruction plates is the method of choice for reconstruction of segmental mandibular defects. We hypothesized that the use of the newer 2.0-mm locking reconstruction plate (LRP) is not associated with higher rates of complications when compared with larger, previously used plating systems.

METHODS

A retrospective case series of 184 patients undergoing 185 vascularized bone graft reconstruction procedures of the mandible was conducted.

RESULTS

There were 37 plate complications. There was no significant difference in complication rates for the 2 most used plate types (14.5% with the 2.0-mm LRP and 22.2% with the 2.4-mm LRP).

CONCLUSIONS

Use of the smaller 2.0-mm LRP was not associated with an increase in the complications of plate fracture, exposure, infection, or nonunion. Because of its lower profile and ease of application, the 2.0-mm LRP is our plate of choice for mandibular reconstruction.