Risk factors for breakage of biodegradable plate systems after bilateral sagittal split mandibular setback surgery

Recent Advances in Polyesters for Biomedical Imaging

Several synthetic materials exhibiting contrast imaging properties have become vital to the field of biomedical imaging. Polymeric biomaterials and metals are commonly used imaging agents and can assist in the monitoring of therapy response, migration, degradation, changes in morphology, defects, and image-guided surgery. In comparison to metals, most bio and synthetic polymers lack inherent imaging properties. Polymeric biomaterials, specifically polyesters, have gained a considerable amount of attention due to their unique properties including biocompatibility, biodegradation, facile synthesis, and modification capability. Polyester implants and nanomaterials are available on the market or are in clinical trials for many applications including: dental implants, cranio-maxilofacial implants, soft tissue sutures and staples, abdominal wall repair, tendon and ligament reconstruction, fracture fixation devices, and coronary drug eluting stents. This review aims to provide a summary of the recent developments of polyesters with bioimaging contrast properties. The three main approaches to prepare bioimaging polyesters (coating, encapsulation, and functionalization) are discussed in depth. Furthermore, commonly used imaging modalities including X-ray computed tomography, magnetic resonance imaging, ultrasound, fluorescence, and radionucleotide polyester contrast agents are highlighted. In each section, examples of impactful bioimaging polyesters in the five major imaging modalities are evaluated.

Evaluation of the rigidity of sagittal split ramus osteotomy fixation using four designs of biodegradable and titanium plates--a numerical study

PURPOSE

This study was conducted to determine the best design of biodegradable plates for providing rigidity when used for fixation of sagittal split ramus osteotomy.

METHODS

A computerized tomography image of a patient was used to generate a 3D model of a hemi-mandible. Four plate designs were merged with the hemi-mandible. They were (1) straight plate, (2) double straight plate, (3) T-shaped plate, and (4) double Y-shaped plate. Four finite element models were analyzed using the properties of biodegradable materials for the plates, and four additional models were analyzed using titanium alloy properties.

RESULTS

The models predicted that rigidity of fixation would be noticeably less among biodegradable plates than titanium plates. They also predicted that the most rigid design among the titanium plates would be the straight plate, but among the biodegradable plates, it would be the double Y-shaped plate.

CONCLUSION

The double Y-shaped design is recommended when using biodegradable plates in fixation of sagittal split ramus osteotomy.

Comparison of titanium and biodegradable plates for treating midfacial fractures

PURPOSE

The purpose of the present study was to evaluate the use of titanium plates and screws (TPSs) versus biodegradable plates and screws (BPSs) for fixation of midfacial fractures. In addition, complications related to the plates and rates of secondary surgery for plate removal were compared.

PATIENTS AND METHODS

From March 2005 to March 2012, 109 patients were enrolled in this study. Fifty-six patients with TPSs implanted to fix midfacial fractures (group A) and 53 patients with BPSs to treat midfacial fractures (group B) were evaluated. Patients' histories of plate-related nonunion, infection, displacement, pain, and palpability and secondary surgery for plate removal were checked.

RESULTS

None of the study participants developed nonunion issues related to the TPSs or BPSs. Six patients in group A developed complications associated with TPSs and 5 patients underwent secondary surgery for plate removal. One patient (1.8%) had a plate-related infection, 1 patient (1.8%) developed plate extrusion, 1 patient (1.8%) had plate-associated chronic pain, 2 patients (3.6%) complained of palpability, and 2 patients (3.6%) developed psychological problems (1 patient developed 2 complications). In contrast, only 1 patient in group B (2%) complained of temporary palpability, and this problem disappeared over time. None of the patients in group B complained of any other problems.

CONCLUSIONS

The results indicated that BPSs and TPSs have the potential for successfully treating midfacial fractures. BPSs are suitable for treating midfacial fractures and could serve as an alternative for TPSs in selected cases.