Root and canal morphology of mandibular first premolars with radicular grooves

The complexity of root canal systems in mandibular first premolars is determined by the severity of RGs, which can be scored by the ASUDAS. Detecting the incidence of various root canal forms corresponding to each ASUDAS score is useful for calculating the standardized rates from published data of dental anthropology. Understanding the anatomic features of the RG and the internal root canal system is essential for successful dental treatment.