The crown-to-root ratio is a key indicator in clinical decision-making and treatment withi-n dentistry. A favourable crown-to-root ratio influences the feasibility of treatment plans and long-term out-comes, and is central to the entire clinical process across multiple disciplines, including prosthodontics, im-plantology, orthodontics, periodontology, and endodontics. The accuracy of its measurement depends on ad-vances in imaging technology; with the emergence and progress of digital imaging and analysis techniques, the crown-to-root ratio has evolved accordingly, leading to greater precision in diagnosis and treatment. In light of the above, this paper reviews the current state of research on the crown-to-root ratio across vario-us dental disciplines, summarising its applications and considerations within different fields of dentistry, with the aim of providing evidence-based guidance for clinical practice.