Objectives: The aim of this study was to compare short-term and medium-term effects of gingival index (GI) and dental plaque index (PI), according to the tooth position through the oral hygiene education in the diabetic youth. Methods: The total number of participants were 31 diabetics and 87 controls in the city of Daegu. Oral examination and professional oral hygiene care were performed among the 31 diabetic youth who consented to the study at the first visit. The professional oral hygiene care consisted of the tooth brushing method, oral prophylaxis, scaling, fluoride application, sealant and dental auxiliary education. We collected the data from all participants for the identification of oral condition at 2 weeks and 3 months. The #11, #14, #16, #31, #34, #36 teeth were selected for the measurement of the oral hygiene conditions. GI and PI were used for oral hygiene scores. The data was analyzed with SPSS 18.0 program. Results: Both GI and PI were significantly decreased in the treatment group of the 31 diabetic youth in comparison to the controls, by tooth position compared to the baseline (P<0.001). In particular, GI measurements constantly decreased upto 3 months and the PI measurements decreased upto 2 weeks and increased slightly from 2 weeks to 3 months. In the GI measurements, the decrement of #14 was the highest (48.4%) and #36 was the lowest (25.2%) among all teeth. In the PI measurements, the decrement of #14 was the highest (45.5%) and #16 was the lowest (19.8%) among all teeth. In the control group, PI increased on all tooth positions, and GI increased on some tooth positions. Conclusions: The program of professional oral hygiene care in the diabetic youth has improved the oral health care when compared to the controls. We suggest that the sites where oral hygiene is more difficult to control have more oral hygiene education than the other sites.