Objective: Damage of the inferior alveolar nerve is a common complication when implant placement is indicated to replace missing first and second premolars. Therefore, exact position of the mental foramen and the length of the anterior loop must be detected using reliable tools in order to prevent such clinical complication. The purpose of this study was to find out the length of the anterior loop in Vietnamese population to estimate a safe zone for implant placement in interforaminal zone. Method: This study used 112 CBCT scans taken by NewTom Giano Cone-Beam 3D Imaging OPG/CBCT. The length of the anterior loop on both side was assessed using OsiriX DICOM Viewer software. The data collected were compared according to age, gender and side of the mandible. Result: The prevalence of the loop was 92.9% with the mean length being 1.72 ± 1.00 mm (0.0 - 4.91mm). The most common position of the mental foramen was in line with the axis of the second premolar. There was no significant difference between genders or left and right side of the mandible; however, there was a significant difference between age groups (p = 0.010). Conclusion: Most of the samples (92.9%) presented the anterior loop. Therefore, cautions should be taken when placing implant in proximity to the mental foramen to avoid damage to the nerve. No exact distance is considered safe and the use of CBCT with oblique-transverse method is recommended whenever an implant is indicated as it is accurate and easy way to detect and measure anterior loop length.