Root

The root is the portion of a tooth that extends below the cementoenamel junction into the alveolar bone of the jaw, providing anchorage, stability, and a conduit for the neurovascular supply that nourishes the tooth. Each root is covered by a thin layer of cementum, a mineralized tissue that serves as the attachment surface for the periodontal ligament fibers connecting the tooth to the surrounding bone. The internal structure of the root contains the root canal, a narrow channel that houses the pulp tissue extending from the pulp chamber in the crown to the apical foramen at the root tip. Root morphology varies significantly by tooth type, with anterior teeth and premolars typically having one to two roots and molars having two to three roots, though anatomical variations including accessory canals, lateral canals, and bifurcated roots are clinically common.

Root anatomy is central to several areas of dental treatment. In endodontics, successful root canal therapy depends on identifying, cleaning, shaping, and obturating every canal within every root of the affected tooth, and missed canals are a primary cause of treatment failure. In periodontics, furcation involvement, where bone loss extends into the area between the roots of a multi-rooted tooth, creates a distinct clinical challenge that affects both treatment planning and prognosis. In oral surgery, root number, curvature, divergence, and proximity to anatomical structures such as the inferior alveolar nerve and the maxillary sinus are the primary factors that determine whether an extraction will be classified as simple or surgical. Root fracture, whether from trauma or excessive occlusal force, is also a common indication for extraction when the fracture extends below the alveolar crest.

On the billing side, root anatomy is embedded in the CDT code structure for endodontic and surgical procedures. Root canal therapy codes are differentiated by tooth type, which serves as a proxy for root and canal complexity, with anterior, premolar, and molar categories carrying progressively higher fees. Extraction codes distinguish between erupted teeth with intact roots and residual root tips requiring separate removal. When root anatomy presents unusual challenges such as dilacerated roots, hypercementosis, or ankylosis, the clinical documentation should describe these findings to support the procedure code and fee submitted. Practices that invest in advanced imaging to evaluate root anatomy before treatment can improve both clinical outcomes and billing accuracy by identifying complex anatomy that warrants specialist referral or an elevated procedural code.