Introduction: Nowadays, using implants as a choice in patient's treatment plans has become popular. The aim of this study was to determine the prevalence of mandibular lingual and maxillary buccal concavity, mean concavity depth and angle and its relation to age and gender.

Materials and Methods: In 200 CBCT, concavity depth and angle were measured in 2 mm superior to the inferior alveolar canal in the mandibular first molar area and in 1 mm distance from nasal floor in the midpoint region of maxillary lateral incisor and canine. Concavity depth and angle relationships with age and gender have been evaluated using Spearman Correlation and a t-test.

Results: Mean and standard deviation of lingual concavity, concavity angle and ridge angle in mandible were 1.3±1.54 mm, 15.45±16.19 and 10.13±6.1. Mean and standard deviation of buccal concavity and concavity angle in maxilla were 5.35±1.03 mm and 30.6±5.75. Mandibular concavity depth was zero in 44% of subjects and more than zero in 56%. Results were more than 3 mm in maxillary samples. There was a linear relationship between mandibular concavity depth and age equaled to -0.27, p=0.007 and for mandibular concavity angle and age equaled to -0.25, p=0.01. There was no significant relationship between mandibular ridge angle and age. In maxilla, there was no linear relationship between age and gender with any other variables

Conclusion: It is necessary to provide more information on these regions' anatomy using CBCT cross sections before implant placement.