Background: Dental and oral diseases are one of the public health problems in Indonesia. Impact is a tooth that normally erupted or blocked, usually by nearby teeth or pathological tissue. The term impaction means that some teeth or all teeth that can not erupt perfectly to the occlusal surface, due to obstructions by adjacent teeth, bones, and surrounding soft tissues. Purpose of the study: To provide information on the features of the frequent molar implications of three by using panoramic radiographs at RSGM UMY. Design research: The type of research used in this study is descriptive with cross sectional design. This study was conducted by taking secondary data from X-ray panoramic photographs in patients undergoing third molar impaction. Result: 40 panoramic X-ray images that had impact of mandibular third molar at RSGM UMY from January to May 2016 Obtained moderate amount of impaction was class II that was 64 cases (83,1%), based on second molar relationship that is position B The cases of 48 cases (62.3%), and based on angulation were mesioangular, 51 cases (53.2%) and based on the type of kelmain, the more affected women were 28 cases (70%). Based on age, the lowest mandibular third molar impaction at the age of 17-27 years was 23 (57.5%). The impact of mandibular third molar by area of residence, the most implicated is on the Bantul area, ie as many as 13 cases (32.5%).