This research is conducted in the department of pediatric dentistry at the faculty of dentistry, Tishreen University in the period between 10/2011 to 10/2012. It included 150 children (100 males and 50 females), their ages between 6-15 years. This research was carried out on the models of the jaws, by measuring the vertical dimension occlusal (VDO). And the results were: 1- The average of the first group (6-8 years) = 33,41 mm 2- The average of the second group (9-11 years) = 35,22 mm 3- The average of the third group (12-15 years) = 38,40 mm The final result of the average of (VDO) in children was 34,79 mm The importance of this study is how to return the correct vertical dimension when it is lost.