American Board of Orthodontics (ABO) Practice Exam 2025 - Free Orthodontics Practice Questions and Study Guide

The correct marker for monitoring bone formation is PINP, which stands for Procollagen Type I N-Terminal Propeptide. This biomarker is a byproduct of collagen synthesis; when new bone is formed, specifically the type I collagen, PINP is released into the bloodstream. Therefore, its levels reflect the activity of osteoblasts, the cells responsible for bone formation.

In the context of orthodontics and bone remodeling, monitoring markers like PINP is crucial for evaluating how well the bone is responding to mechanical forces applied during treatment. Elevated levels of PINP indicate increased bone formation, essential for the success of orthodontic tooth movement.

Other markers that can be mentioned include CTx, which is associated with bone resorption, and therefore, does not indicate bone formation. Likewise, ALP (Alkaline Phosphatase) can be related to both bone formation and liver function; however, it is less specific to just bone formation compared to PINP.