Background: Third molar (M3) agenesis and impaction are associated with evolution, changed dietary habits, and human jaw growth. The aim of the study was to radiographically evaluate the prevalence of M3s agenesis, impacted M3s with different impaction patterns, and the approximation of Inferior Dental Canal (IDC) with impacted mandibular M3s roots among the Sriganganagar population. Methods: The study included 700 randomly selected subjects from OPD with an age range of 25–45 years. Digital OPGs were taken for all subjects using Kodak 8000C digital OPG machine. The M3 impaction patterns were evaluated using Winter’s classification. Results: The prevalence of subjects with at least one M3 agenesis was found to be 34.1% and with 95% confidence interval was 30.6% to 37.6%. The overall M3s agenesis was 16.8% with more prevalence in the males. The patients with agenesis of one M3, two M3s, three M3s, and four M3s were 14.4%, 11.3%, 3.7% and 4.7%, respectively. M3 agenesis was more in the upper jaw and on the left side. The total impacted M3s were 21.11% with more prevalence in mixed diet subjects. Mesioangular was most common impaction pattern, and notching was most prevalent IDC relationship with impacted mandibular M3s roots. Conclusion: This study highlighted the evolutionary increasing M3 agenesis and the importance of diagnostic OPG for seeing the status of M3s in jaws.