Computer aided surgery is popular and useful in the field of oral and maxillofacial surgery, because of the possibility of simulation with a high accuracy. In all aspects of surgery, proper planning facilitates more predictable operative results, however before the use of virtual planning, much of this relied on 2 dimensional (2 D) imaging for treatment planning on a 3 dimensional (3 D) object and surgical trial and error. With real time instrument positioning and clear anatomic identification, a computer assisted navigation system (CANS) is exceptionally helpful in maxillofacial surgery. These techniques enable performing precise bony ablation and reconstruction, and also decrease surgical time and donor site defect.