[The mean of Downs and northwestern analysis in adults].

An angle analysis and linear analysis are popularly used in clinical orthodontics. Downs analysis and Northwestern analysis are two methods of angle analysis, and the mean values reported by Iizuka in 1963 are still used. However in Japan each generation's constitution (height, weight) tends to increase year by year. For example, the mean height and weight of adult males (23 years old) have increased by 5.0cm and 7.6kg as compared with nearly 20 years ago. Therefore the mean of 20 years ago may not be appropriate. Analytical values at normal occlusion Japanese adults by Kayukawa, Iizuka, Ishikawa, Yamauchi, Miura, Iwazawa and, most recently by Asai in 1973. We obtained these values and determined the validity of currently used values.