American Board of Orthodontics (ABO) Practice Exam

The primary effect of excessive force on the periodontal ligament is hyalinization. When orthodontic forces are applied to teeth, they create changes in the periodontal ligament and surrounding structures. Hyalinization refers to the process where the periodontal ligament fibers are compressed to the point that they undergo a change in their biological makeup, leading to a glassy, homogeneous appearance.

This glassy area forms as a result of tissue that becomes necrotic when subjected to intense and prolonged forces, and it indicates a failure of the customary remodeling processes. Instead of normal bone remodeling occurring, which involves the activation of osteoclasts and osteoblasts to form and resorb bone, hyalinization can halt these processes. This stagnant condition can hinder proper alignment and movement of the teeth, potentially prolonging treatment time and causing discomfort.

While concepts such as bone remodeling and increased vascularity are important in orthodontic treatment, excessive force leads to hyalinization, clearly illustrating a disruption in the normal physiological response of the periodontal ligament and alveolar bone. Minimization of pain is not an effect of excessive force; rather, it can increase discomfort and other complications during the treatment process. Therefore, hyalinization is a critical factor to understand in the context of how excessive forces