In the process of tooth growth, there are sometimes abnormalities such as teeth that experience malocclusion or crowded teeth. This can lead to impaired speech, mastication and aesthetics poblem, even make food easier to accumulate between crowded teeth. For this reason, orthodontic care is needed to treat crowded teeth because it will get well-aligned teeth so that it is easier to maintain cleanliness and healthy teeth and mouth to improve masticatory function, speech function, and improve appearance. Even so, in the process of orthodontic treatment, there are some changes in shape both in the jaw and soft tissue on the face and basically, Islam emphasizes hygiene and health, so orthodontic treatment with the aim of correcting mastication and phonetics accompanied by aesthetics is permissible. The purpose of this study was to determine the description of knowledge on orthodontic treatment in Islam at the students of the Faculty of Medicine and Health Sciences, University of Muhammadiyah Yogyakarta. The method of this study was descriptive observational, with a random sampling method. The subject were 105 students Sample inclusion criteria are muslim students who actively study at the Faculty Medicine and Health Sciences at the University of Muhammadiyah Yogyakarta, namely all students on third and fourth year. The sample exclusion criteria were the student of the Faculty Medicine and Health Sciences at the University of Muhammadiyah Yogyakarta who were not willing to become research respondents and the students who were fulfill the questionnaire uncompletely. The results showed that the level of knowledge of orthodontic treatment according to Islam had a high level of knowledge with a percentage of 66,7%. The results of the questionnaire were analyzed using descriptive statistical analysis which is frequency distribution, so that it would be known that the trend of research results included in the categories of very low, low, medium, high or very high. The conclusion of this study is that students are highly knowledgeable about orthodontic treatment according to Islam. The majority of students know that orthodontic treatment in Islam is permissible with health goals, whereas if the goal of treatment is to improve aesthetics and change the form of Allah Subhanahu wa Ta'ala creation it is not permissible.