Root canal system is one of the most complex systems of all anatomic study. The Anatomical Apical landmarks are considered extension limits for RC instrumentation and filling while preserving the apical foramen to avoid complications like zipping, tearing of the foramen. Its unquestionable the most critical area in deterring the health, success and failure of the RCT procedure. This book focuses on the Anatomy of apical region of the root canal and clinical considerations of the Apical end at various steps of the root canal procedure, the various mishaps in apical third, the prevention of these mishaps and treatment following the mishaps and the surgical aspect of the same. The chapters highlight the importance to visualise and to have knowledge of the internal anatomy relationships before undertaking the endodontic therapy. The vitality of using the armamentarium at their disposal to locate and treat the entire root canal system. Since root apex is morphologically, therapeutically a challenging zone and prognostically an important but unfortunately unclear area, so inadequate attention may lead to serious complications.