The most common surgical procedure performs by an oral surgeon is the surgical removal of impacted mandibular third molars. Evaluating the degree of difficulty of these wisdom teeth surgical removal is extremely important to plan proper treatment for reducing the risk of complications. This study aims to analyze the accuracy of the difficulty index of impacted mandibular third molar through panoramic radiograph by using proposed modified Kharma scale correlate with an actual procedure through a modified Parant scale for prognosticating of the index of difficulty. The difficulty of the surgical removal of 214 lower third molar treated in the College of Dental Medicine, Rangsit University, was predicted by the modified Kharma and modified Parant (MK/MP) scale. Finally, these results were compared with the actual procedure of individual cases in terms of the modified Parant (MP) scale. Only 50% (107 from 214) of teeth (95% CI: 0.4-0.6) are correspondence in number between preoperative MK/MP scale and postoperative MP scale. In addition, Cohen/Conger’s Kappa statistics showed the calculated result of 0.2313, which the Benchmark scale as a reference qualified as fair. Statistic results showed little value for the prediction of the surgical removal’s difficulty by the proposed MK/MP scale. The revision of the scales must be taken other radiological and clinical information’s as well as weighing score into account for further study.