Different orthodontic anomalies are followed by different depths of the palate. The aim of this research was to determine the palate depth in patients who have narrow upper jaws and in patients with normal upper jaw development. The study models of 386 patients were divided into two groups (120 with narrow upper jaws and 266 patients normal upper jaw development). The depth of the palate was measured on the level of first and second premolars, first permanet molars as well as the posteror width of the upper jaw by a three-dimensional dental compass according to Korkhaus and the palate depth index (PDI) was calculated according to the PD/PW x 100 formula. The results show that the PDI in patients of both sexes is statistically much higher than in patients with normal upper jaw development (p< 0,01) The average PDI value in male patients with narrow upper jaw is 41,76 and in female patients it is 38,60. The average PDI value in male patients with normal upper jaw development is 35,89 and in female patients it is 38,60. According to the average PDI values, both sexes with normal upper jaw development have a medium-developed palate, male patients with a narrow upper jaw have a high palate, while the PDI values in female patients are on the border between medium and high palate. The values of palate depth increase distally from the first premolar level towards first molars in both groups of examinees.
