This thesis is based on longitudinal monitoring of developmental changes of the oronasal region in a group of children from 7 to 17 years. Growth and shape changes, variability and sex dimorphism were monitored using 492 3D facial models of 40 boys and 47 girls. These models were obtained by yearly scanning children aged 7 to 12 years and 12 to 17 years. The Vectra 3D optical scanner was used to obtain the models and data were evaluated using classical and geometric morphometry methods (T-test, DCA, Per vertex T-test and Principal component analysis). The results of the analyses were visualized using superprojection color maps of average faces and significance maps that show statistically significant regions of oronasal region changes. During the period under review, the growth of the oronasal region is evident in both girls and boys. The most intense growth occurred in the area of the nasal spine in both sexes, so there was a lengthening of the nose. Overall, the oronasal region extended and expanded to acquire a more convex shape. Growth intensity increased in girls from 10 years and in boys from 11 years. Sexual dimorphism was pronounced up to 11 years, between 12 and 13 the differences were not as pronounced as in the previous age categories, and these changes began to increase again from 14...