Polymethylmethacrylate Microspheres are Immunologically Inert in Mouse Tissues.

Nowadays, aesthetic concerns have gained attention, especially by patients looking for a less invasive alternative to minor facial corrections. Polymethylmethacrylate (PMMA) is widely used as a soft tissue filler; the demand for this polymer has increased, and along with it, there are some reports of adverse reactions. Such adverse reactions stem from consequences of immune and inflammatory reactions to PMMA. Some animal models have been used to unravel the causes of these reactions, among other factors involving the management of PMMA. The aim of this study was to determine the immunogenic profile of PMMA implantation in different anatomical planes of mice, over up to 360 experimental days. In this study, BALB/c mice were divided into 30 groups for immune evaluation of the interaction between the organism and the polymer; 2% PMMA was implanted subcutaneously, 10% intramuscularly and 30% in periosteal juxtaposition and followed during five experimental days (7, 30, 90, 180 and 360 days after implantation-DAI). Pro- and anti-inflammatory cytokines (IL-2, IL-4, IL-6, IFN-gamma, TNF, IL-17A, IL-10 and TGF-beta) were quantified in all experimental days. There was no statistical difference between the groups analyzed considering the evaluated parameters. Therefore, at all implanted depths, PMMA behaved inertly in a murine model.No Level Assigned This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Tissue Remodeling After Implantation with Polymethylmethacrylate: An Experimental Study in Mice.

Polymethylmethacrylate (PMMA) is a filler used for aesthetic and/or repair purposes. The response to the implantation of biomaterials varies according to factors related to the patient, the professional responsible for the application and the material used. In vitro and in vivo experimental models have been used to study aspects such as the organism/biomaterial interface and the role of macrophages, dendritic cells and neutrophils. This study aimed to characterize the inflammatory reactions related to polymer concentration, implantation depth and exposure time. Different concentrations of PMMA were implanted in different anatomical planes in mice. The consequences of contact with PMMA, from structural changes to the inflammatory characteristic of tissue damage, were histologically evaluated. The implantation interfered in the morphological structure of the region where it was implanted, expanding it and due to the inflammatory reaction generated, by the presence of the vehicle in the initial phase and by the collagen produced in the chronic phase. The 30% concentration of PMMA induced a greater presence of foreign body giant cells both subcutaneously, at 7, 30 and 90 days after implantation (DAI), and intramuscular at 30DAI. Tissue remodeling was more expressive in the subcutaneous region with significant density of the extracellular matrix at 90DAI. In conclusion, the foreign body reaction resulting from the implantation process acquires different characteristics depending on the anatomical plane and the concentration of implanted product, where the more superficial the implantation plane, the greater the inflammatory reaction. Moreover, PMMA concentration and the depth of implantation did not influence the collagen production.No Level Assigned This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors https://www.springer.com/00266.

Polymethyl Methacrylate (PMMA) in the Treatment of a Case of Hemifacial Microsomia.

Hemifacial microsomia (HMF) is a morphological alteration characterized by facial deformities. These alterations are a consequence of a congenital anomalous development of the first and second branchial arches. It may present a genetic or environmental origin or a mixture of both and is considered mostly multifactorial. The clinical presentation varies; however, some characteristics are predominant such as unilateral mandible hypoplasia, agenesis or malformation of the auricular pavilion, and agenesis or malformation of the eye globe. The aim of this paper was to report a clinical case of a patient with late diagnosis of HMF which presented multiple deformities and received treatment with polymethyl methacrylate (PMMA) implant in different concentrations. Aiming for facial harmony, the PMMA implant occurred in the following regions: canine fossa, nasolabial sulcus, mandible, Bichat Ball, chin outline, lip contour, nose base, columella, nose tip, and dorsum. The treatment resulted in significant improvement in the facial symmetry.