American Board of Orthodontics (ABO) Practice Exam 2026 - Free Orthodontics Practice Questions and Study Guide

The association of foreign bodies such as silicone or PTFE (polytetrafluoroethylene) implants predominantly leads to a giant cell reaction. This type of response occurs due to the body’s immune system recognizing these materials as foreign. When large particles or materials cannot be effectively phagocytized by the usual macrophages, they stimulate the formation of multinucleated giant cells. These giant cells arise from the fusion of macrophages in a concerted effort to encircle and attempt to eliminate the foreign material.

Giant cell reactions are particularly characteristic in the presence of materials that elicit a chronic inflammatory response, which is common with inert substances like silicone and PTFE. The formation of these cells signifies an ongoing process where the immune system attempts to isolate and manage the foreign body, showcasing the balance between inflammatory and fibrotic responses in tissue integration and repair strategies.