Effectiveness of Customized Handle Toothbrush

Participants will be examined to ensure that the participants have met the sample entry criteria, then the participants will be randomly assigned to four groups each one according to a group: 1. A group of healthy children using conventional toothbrush (12 children). 2. A group of healthy children using toothbrush with Customized Handle (12 children). 3. A group of children with Down syndrome using conventional toothbrush (12 children). 4. A group of children with Down syndrome using toothbrush with Customized Handle (12 children). Secondly, 1. Researcher will take an impression of the child hand grasp silicon impression material. 2. Researcher will scan the impression with a model scanner and copy it to the computer, then convert it -through a specialized program- to a 3D analog. 3. The program will print the digital analog via the 3D printer using Poly Lactic Acid compound and convert it into a model similar to the patient hand grasp, this model has a place to put the toothbrush. Third, Brushing instructions: 1. The researcher will teach the participants how to brush by using (tell-show -do) technique. 2. The brushing method that will be used is the modified Stillman technique. 3. Brushing duration must be at least 3 minutes. 4. The brushing must be twice a day. 5. The amount of toothpaste is pea size. Finally, Mechanism of examination and follow up: After apply the plaque disclosing solution on the teeth with a bond brush, the plaque will be evaluated with Turesky Modification Quigley-Hein Plaque Index, checking on the buccal and lingual surfaces of all the teeth existing in the participant's mouth. The participants will be observed in the same day, before and after brushing, and after one week and three weeks