Background: Malocclusion is one of the important problems in the field of dental and oral health in Indonesia. Dental and oral health in children is an important factor that must be considered as early as possible. Therefore, knowledge of children, especially knowledge of malocclusion, must be considered more because if a children experiences malocclusion it can affect tooth grow that a laterage. Down Syndromeis a chromosomal disorder thatresults in mental retardation. Mental retardationis a worldwide problem with major implications, especially for developing countries. It is estimated that the incidence of severe mental retardationisabout 0.3% ofthe total population, andnearly 3% havean IQ below 70%. As human resources, ofcourse they cannot be utilized, because 0.1% of these children need care, guidanceandsupervisionthroughouttheirliving.Objective: To review the frequency of malocclusion in DownSyndromechildren. Methods: Scientific evidence and clinical cases were drawn from the literature to support this review and information on the frequency of malocclusion in childrenwith Down Syndromewascollected.Result/Discussion: There are several types of malocclusion that often occur in children with DownSyndrome. Some of them are associated with class III Anglemalocclusion, crowding, and anterior open bite. Conclusion:Down Syndrome is one of the most studied genetic syndromes because of its frequency in our population and its medical significance. Malocclusion was observed in 92% of subjects with Downsyndrome. The incidence of malocclusion is higher in children/adolescents with Down Syndrome than in individuals without the syndrome. Class III malocclusion is most frequently observed.