Location of injected polymethylmethacrylate microspheres influences the onset of late adverse effects: an experimental and histopathologic study

Abstract

Polymethylmethacrylate (PMMA) has been widely used in the correction of wrinkles because of its long-lasting cosmetic improvements. However, side effects and complications may occur, and its clinical appearance on the oral mucosa can be similar to that of inflammatory or neoplastic disease. The aim of this research was to compare the clinical and histopathologic responses to PMMA injected by two different methods. Twenty-two rats received an injection of PMMA using the tunneling technique (gold standard), with subcutaneous deposition of the filler in the face, or a variation of the technique with transcutaneous submucosal deposition of the filler in the cheek. The tissue reaction was analyzed clinically every 24 hours during the first week, then once a week for the following 3 months. Histologic evaluation was based on the local inflammatory response to the filler. No clinical changes were observed during the initial evaluation period (0–14 days). After 14 days, only the submucosal group showed extra-oral enlargement (n=4, 18.2%). Histopathologic analysis revealed nodule formation in four animals (18.2%) in the submucosal group, with no nodules observed in the subcutaneous group. The data obtained in this study demonstrate that the technique used to deliver the filler may influence the risk of adverse reactions.

Clinical commentary about foreign body complications over 20 years after polymethyl‐methacrylate face implants and control of late sequelae with Polynucleotides Highly Purified Technology (PN‐HPT®)

“…A fine point to discuss: do the later episodes testify to the actual development of late, slowly evolving foreign body granulomatous complications, with the first occurrence about 15 years ago and a recent recurrence? Sclerosing granulomas usually arise in 6–24 months, but granulomas are known to arise many years after the PMMA implant 11,12 …”

“…Sclerosing granulomas usually arise in 6-24 months, but granulomas are known to arise many years after the PMMA implant. 11,12 The problem, more severe in the past, was mainly related to the macrophage phagocytosis of the microspheres <20 µm. Such tiny PMMA beads were pretty abundant in Arteplast ® , the first-generation PMMA formulation unsurprisingly burdened with an incidence of sclerosing granulomas up to 2.5%, but new technologies abated their proportion in the second-generation Artecoll ® formulation.…”

Potential of Migration and Tissue Reactions to Intraperitoneally Implanted Polymethyl Methacrylate in Wistar Rats

“…Impurities on the surfaces of the PMMA microspheres might be primarily responsible for stimulating immune reactions against the polymer; these reactions manifest histologically by the formation of foreign-body granulomas [34,35]. However, it is unclear whether this acute inflammatory process is directly associated with PMMA implantation, as granulomatous foreign-body reactions may occur up to 6 years after the subcutaneous implantation of PMMA [22,35].…”

“…However, it is unclear whether this acute inflammatory process is directly associated with PMMA implantation, as granulomatous foreign-body reactions may occur up to 6 years after the subcutaneous implantation of PMMA [22,35].…”

“…In addition, the collagen is replaced by connective tissue at approximately 2-3 months after implantation. Therefore, an observation period longer than 1 month is needed to accurately assess fibroplasia onset with collagen deposition [35][36][37][38].…”