BACKGROUND: Information about long-term changes of the shape of the gingival margin is missing. AIM: To monitor 8 year changes of the gingival contour occurring in adolescents and adults and relate these changes to dentofacial growth. SUBJECTS AND METHOD: Forty adolescents (mean age 16.3), and 14 adults (mean age 29.7) were included in the study with photographs, radiographs and casts taken 2 and 10 years after orthodontic treatment. The gingival contour of upper central incisors and the midline passing through the contact surface of both teeth were traced digitally using calibrated photographs. Changes were measured on seven standardized lines of the gingival contour. Lower facial height changes and tooth eruption were measured using lateral cephalograms. RESULTS: Adolescents and adults showed a central mean apical displacement of the gingival margin of 0.51 mm (SD 0.4 mm) and 0.13 mm (SD 0.17 mm), respectively. This displacement decreased by moving away from the centre. The gingival displacement was associated to the individual's lower facial height augmentation, r=0.63 (p<0.001). CONCLUSIONS: Apical displacement of the gingival contour of the upper central incisors takes place during adolescence following a semi-lunar shape. Growth explains parts of these changes.