Aim. Aim of the study was to assess differences of measurement of edentulous ridge's height towards referent line of mandibular basis, and separately towards lower edge of panoramic radiograph. Material i methods. 231 panoramic radiographs (167 of edentulous individuals and 64 of maximally toothless individuals, aged 43 to 89 years) were selected. Two methods of measurement were applied: method of selection of distance height on the line from edentulous ridge to line of a base of edentulous mandible, and measurement of height from edentulous ridge to lower edge of panoramic radiograph. Results. Pearson's r=0.604 (r=0.613 for men, and r=0.591 for women) was calculated, indicating statistically significant differences of heights measured by each method. Conclusion. Significant differences of height of edentulous ridge were measured, because of differences in positions and inclinations of lines. Resorption of edentulous ridge and concave form of ridge influence numerical values of height of edentulous ridge. Height which was measured onto mandibular base line is reliable parameter in situations where resorption changed edentulous ridge's form. .
