What term is more appropriately used to describe the neck of a tooth?

The term that is most appropriately used to describe the neck of a tooth is the cementoenamel junction (CEJ). The CEJ is the area where the enamel of the crown meets the cementum of the root, marking the transition from the visible part of the tooth to the part that is anchored in the jawbone. This anatomical feature is critical in dentistry as it plays a key role in identifying tooth health and assessing conditions like gingival recession or periodontal disease.

The other terms listed are used to refer to different aspects of tooth structure. The dentinoenamel junction (DEJ) refers to the interface between the enamel and dentin layers of the tooth, not the neck. The cementodentinal junction (CDJ) is the boundary where the cementum and dentin meet, which is not equivalent to the neck of the tooth. The term "margin," while used in some dental contexts to describe the edge or perimeter of a restoration or tooth, does not specifically denote the neck of the tooth. Thus, the CEJ is the most accurate term for describing the neck of a tooth.