Resorbable Implants for Mandibular Fracture Fixation: A Systematic Review and Meta-Analysis

Complications of Mandibular Fracture Repair

Mandible fracture management has evolved dramatically. Therefore, the variety of surgical complications associated with mandibular fractures, and their incidences, have continued to change as well. This article aims to assess the most common and most concerning complications that can occur secondary to management of mandibular fractures by examining categories of complication types. This article also explores factors and techniques associated with reduced rates of complications as well as the management of complications.

Advances and Prospects in Materials for Craniofacial Bone Reconstruction

The craniofacial region is composed of 23 bones, which provide crucial function in keeping the normal position of brain and eyeballs, aesthetics of the craniofacial complex, facial movements, and visual function. Given the complex geometry and architecture, craniofacial bone defects not only affect the normal craniofacial structure but also may result in severe craniofacial dysfunction. Therefore, the exploration of rapid, precise, and effective reconstruction of craniofacial bone defects is urgent. Recently, developments in advanced bone tissue engineering bring new hope for the ideal reconstruction of the craniofacial bone defects. This report, presenting a first-time comprehensive review of recent advances of biomaterials in craniofacial bone tissue engineering, overviews the modification of traditional biomaterials and development of advanced biomaterials applying to craniofacial reconstruction. Challenges and perspectives of biomaterial development in craniofacial fields are discussed in the end.

Pediatric Maxillofacial Trauma: Insights into Diagnosis and Treatment of Mandibular Fractures in Pediatric Patients

Aim

To assess the diagnostic and therapeutic approaches in pediatric mandibular fractures with regards to fracture pattern and localization.

Patients and methods

This retrospective study included patients under the age of 17 years that presented to the Department of Oral and Maxillofacial Surgery at Charité-Universitätsmedizin Berlin with mandibular fractures over an 11-year long period (2010-2020). Medical records were analyzed for age, gender, injury mechanism, clinical presentation, imaging modalities, fracture pattern, and fracture management. Statistical analyses included descriptive statistics, normality testing, and Mann-Whitney U tests.

Results

A total of 91 pediatric patients (23 females and 68 males) presented with mandibular fractures. The majority of mandibular fractures occurred in patients aged 13-16 years (67.0%, n = 61). The main causes were activities of daily life (34.1%), followed by assault (25.3%). Malocclusion and pain upon mandibular joint compression were documented in 72.5% and 51.7% of patients, respectively. The most frequently applied radiological diagnostic tool was a panoramic X-ray (49.5%). The main fracture patterns were single (42.9%) and double fractures (48.4%). An age-adapted surgical approach using open reduction and internal fixation (ORIF) was the most frequent management (61.5%). A conservative approach was favored in cases of condylar head fractures. Resorbable plates were used in eight cases of ORIF (8.8%).

Conclusion

Treatment regimens should be carefully selected based on the unique anatomy of the pediatric patient with regards to centers of growth and dentition phase, to restore stomatognathic function and to maintain adequate skeletal growth and eruption of teeth.

Clinical significance

This study illustrates the challenges of mandibular fracture management in the pediatric patient.

How to cite this article

Hofmann E, Koerdt S, Heiland M, et al. Pediatric Maxillofacial Trauma: Insights into Diagnosis and Treatment of Mandibular Fractures in Pediatric Patients. Int J Clin Pediatr Dent 2023;16(3):499-509.

Resorbable Versus Titanium Rigid Fixation for Pediatric Mandibular Fractures: A Systematic Review, Institutional Experience and Comparative Analysis

Study Design

Pediatric mandible fractures mandate special consideration because of unerupted teeth, mixed dentition, facial growth and the inability to tolerate maxillomandibular fixation. No consensus exists as to whether resorbable or titanium plating systems are superior with regards to clinical outcomes.

Objective

This study aims to systematically review and compare the outcomes of both material types in the treatment of pediatric mandible fractures.

Methods

After PROSPERO registration, studies from 1990-2020 publishing on outcomes of ORIF of pediatric mandible fractures were systematically reviewed according to PRISMA guidelines. An additional retrospective review was conducted at a pediatric level 1 trauma center.

Results

1,144 patients met inclusion criteria (30.5% resorbable vs. 69.5% titanium). Total complication rate was 13%, and 10% required a second, unplanned operation. Complication rates in the titanium and resorbable groups were not significantly different (14% vs. 10%; P = 0.07), and titanium hardware was more frequently removed on an elective basis (P < 0.001). Condylar/sub-condylar fractures were more often treated with resorbable hardware (P = 0.01); whereas angle fractures were more often treated with titanium hardware (P < 0.001). Within both cohorts, fracture type did not increase the risk of complications, and comparison between groups by anatomic level did not demonstrate any significant difference in complications.

Conclusions

Pediatric mandible fractures requiring ORIF are rare, and hardware-specific outcomes data is scarce. This study suggests that titanium and resorbable plating systems are equally safe, but titanium hardware often requires surgical removal. Surgical approach should be tailored by fracture anatomy, age-related concerns and surgeon preference.

Bone Union Quality after Fracture Fixation of Mandibular Head with Compression Magnesium Screws

For some years now, fixation devices created with resorbable magnesium alloys for the mandibular head have been clinically available and are beginning to be used. It is thus valuable to evaluate the quality of unions in these cases. The aim of this study was radiological comparison of magnesium versus titanium open reduction and rigid fixations in the mandible condylar head. Thirty-one patients were treated for fractures of the mandibular head with magnesium WE43 alloy headless compression screws (diameter 2.3 mm) and, as a reference group, 29 patients were included with similar construction titanium screws (diameter 1.8 mm). The 12-month results of the treatment were evaluated by the texture analysis of CT. Near similar treatment results were found with magnesium screws in traditional titanium fixation. Magnesium screws result in a higher density of the bone structure in the mandibular head. Conclusions: The quantitative evaluation of bone union after surgical treatment of mandibular head fracture with magnesium compression headless screws indicates that stable consolidation was achieved. Undoubtedly, the resorption process of the screws was found to be incomplete after 12 months, evidenced by a marked densification of the bone structure at the fracture site.

Tailoring mechanical properties and degradation rate of maxillofacial implant based on sago starch/polylactid acid blend

A polymeric bone implants have a distinctive advantage compared to metal implants due to their degradability in the local bone host. The usage of degradable implant prevents the need for an implant removal surgery especially if they fixated in challenging position such as maxillofacial area. Additionally, this fixation system has been widely applied in fixing maxillofacial fracture in child patients. An ideal degradable implant has a considerable mass degradation rate that proved structural integrity to the healing bone. At this moment, poly(lactic acid) (PLA) or poly(lactic-co-glycolic acid) (PLGA) are the most common materials used as degradable implant. This composition of materials has a degradation rate of more than a year. A long degradation rate increases the long-term biohazard risk for the bone host. Therefore, a faster degradation rate with adequate strength of implant is the focal point of this research. This study tailored the tunable degradability of starch with strength properties of PLA. Blending system of starch and PLA has been reported widely, but none of them were aimed to be utilized as medical implant. Here, various concentrations of sago starch/PLA and Polyethylene glycol (PEG) were composed to meet the requirement of maxillofacial miniplate implant. The implant was realized using an injection molding process to have a six-hole-miniplate with 1.2 mm thick and 34 mm length. The specimens were physiochemically characterized through X-ray diffraction, differential scanning calorimetry, thermogravimetric analysis, and Fourier Transform Infrared spectroscopy. It is found that the microstructure and chemical interactions of the starch/PLA/PEG polymers are correlated with the mechanical characteristics of the blends. Compared to a pure PLA miniplate, the sago starch/PLA/PEG blend shows a 60-80% lower tensile strength and stiffness. However, the flexural strength and elongation break are improved. A degradation study was conducted to observe the mass degradation rate of miniplate for 10 weeks duration. It is found that a maximum concentration of 20% sago starch and 10% of PEG in the PLA blending has promising properties as desired. The blends showed a 100-150% higher degradability rate compared to the pure PLA or a commercial miniplate. The numerical simulation was conducted and confirmed that the miniplate in the mandibular area were shown to be endurable with standard applied loading. The mechanical properties resulted from the experimental work was applied in the Finite Element Analysis to find that our miniplate were in acceptable level. Lastly, the in-vitro test showed that implants are safe to human cell with viability more than 80%. These findings shall support the use of this miniplate in rehabilitating mandibular fractures with faster degradation with acceptance level of mechanical characteristic specifically in case of 4-6 weeks bone union.

Foreign Body Reaction to Poly-D-L-Lactic Acid Resorbable Plates Used in Craniofacial Surgery

Resorbable surgical materials are often used in the pediatric population to provide fixation in the growing skeleton. Although foreign body reactions to poly-D-L-lactic acid (PDLLA) plates and screws have been previously reported in other fields, to date PDLLA polymers have been well-tolerated in the setting of craniofacial surgery. The authors report a case of a previously healthy 4-month-old patient with Crouzon syndrome who underwent a frontal-orbital advancement with resorbable PDLLA plates and screws and subsequently experienced extensive foreign body reactions and wound healing complications.

In vivo osseointegration and erosion of nacre screws in an animal model

The use of resorbable devices for osteosynthesis has become a subject of interest. Nacre has been proposed as a resorbable and osteoconductive material favoring bone apposition without triggering an inflammatory reaction. We compared the in vivo osseointegration and erosion of nacre screws in an animal model with titanium screws. Implantation of similar nacre and titanium screws was performed in the femoral condyles of adult rats. Animals (n = 41) were randomized in four groups sacrificed at day one, 1, 6, and 12 months. Microcomputed tomography (microCT) allowed 3D morphometry of erosion of nacre. Osseointegration was measured as the volume of trabecular bone bone volume/tissue volume (BV/TV) in a standardized volume of interest around each screw. Undecalcified bone histology was also done. Gross examination revealed a similar clinical osseointegration for titanium and nacre screws. A progressive erosion of nacre screws, but no erosion of titanium screws, was observed in microCT. The volume of nacre screws progressively decreased over time whereas no modification occurred for titanium. For titanium screws, BV/TV remained stable throughout the study. For nacre screws, the BV/TV decrease was not statistically different. A significant difference was found between nacre and titanium screws at 6 months but not at 12 months. The screw heads, outside the bone shaft, were not eroded even after 12 months. Erosion of nacre occurred during the entire study period, only within the bone shaft in direct contact with bone marrow. Bone apposition was observed on nacre surfaces without signs of erosion. Nacre is a promising biomaterial in maxillofacial surgery.

Are Magnesium Screws Proper for Mandibular Condyle Head Osteosynthesis?

Recently, magnesium alloys have gained a significant amount of recognition as potential biomaterials for degradable implants for craniofacial bone screws. Purpose: The aim of this work was to compare screws made specifically for mandibular head osteosynthesis from different materials. Materials and Methods: Screws measuring 14 mm made by one manufacturer specifically for mandibular head osteosynthesis out of the following materials were selected: magnesium (MgYREZr), titanium (Ti6Al7Nb), and polymer (PLGA). The axial pull-out strength and torsional properties were investigated. Results: Each type of screw presented different pull-out forces (Kruskal–Wallis test, p < 0.001). The magnesium screw had the highest pull-out force of 399 N (cracked without the screw out being pulled out), followed by the titanium screw, with a force of 340 N, and the PLGA screw, with a force of 138 N (always cracked at the base of the screw head without the screw being pulled out). ANOVA was performed for the maximal torques before damage to the screw (torsional properties), revealing that the maximal torque of the magnesium screw was 16 N·cm, while that of the titanium screw was 19 N·cm. The magnesium screw was significantly weaker than the titanium screw (p < 0.05). The measured torque and pull-out force were not related to each other (p > 0.05). Conclusion: Among the screws compared, the metal biodegradable magnesium screw seems to be the most suitable material for multiscrew mandibular head osteosynthesis, considering the condition of the fragile screwdriver socket.