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

CNC cells, or cranial neural crest cells, play a critical role in the development of various structures throughout the body, particularly in the head and neck region. One of their significant contributions is to the dental mesenchyme and pulp, which are foundational elements in the formation of teeth. The dental mesenchyme gives rise to the dentin and pulp of the teeth, while also influencing the development of surrounding structures like the periodontal ligament.

In this context, the role of CNC cells is vital as they have the ability to differentiate into a variety of mesenchymal tissues, providing the necessary cells for tooth formation. This process begins early in embryonic development when CNC cells migrate to the developing arch regions and contribute to several craniofacial structures.

Other choices involve structures that CNC cells do not typically contribute to. For example, while bone marrow and thymus are related to hematopoiesis and immune function, they arise from different progenitor cell lines. Similarly, while sweat and sebaceous glands, as well as skin and hair follicles, are important epithelial structures, they derive from ectodermal origins rather than from CNC cells. Thus, the correct answer reflects the specific contribution of CNC cells to dental tissues, making it clear why "