The lack of the normal physiologic value of tooth mobility for healthy upper permanent incisors with closed apex for children in the Egyptian population was an open channel for me to research & find answers.In order to achieve reliable, unbiased & reproducible results, an objective method such as the Periotest was used. The Periotest M used in this study had so many merits; it was the latest wireless hand unit in the market. It is very light in weight, user friendly & can be easily introduced & accepted by the children.A total sample size of 377 subjects (164 males & 213females) who fulfilled the inclusion & exclusion criteria were randomly included in this study. A periapical radiograph was taken for each child to prevent any bias before taking measurements with the Periotest M.The results of the study showed that the subjects included in this study covered all the age groups (9-13 years old). There was no significant difference between the average Periotest reading between males & females except at the age of 12.5 years which may be attributed to variables such as bone density & root length.Last but not least, the Periotest should be used in the future routinely in the pediatric dental trauma centers since it’s a very economic, light- weighted, easy, quick & very friendly for children.