RADIOGRAPHIC STUDY ON THE RESORPTION OF THE LOWER PART OF THE MANDIBLE

The aim of this study was to investigate if the position of the mental foramen asa stable landmark on panoramic radiographs could be used fo r clinical judgment of alveolar bone resorption. If the distance from the mental foramen (MF) to the lower border of the mandible (LBM) is n ot influenced by resorption then the proportion of the distance from t he crest of alveolar ridge (UBM) to the mental foramen and the distanc e from the mental foramen (MF) to the lower border of the mandible (LB M) could be used as an index for proper clinical diagnosis of the reso rption of the upper part. Measurements were made on 282 panoramic radi ograms by a precise calliper from the center of the mental foramen (MF ) to the lower border of the mandible (LBM) separately for men and wom en. Both samples were divided into 3 groups according to the presence and number of the teeth : group I - all the teeth were present, group II - partially edentuolus subjects and group III - fully edentulous su bjects. Arithmetic means and standard deviations were calculated and t he significance of the differences between the groups was analysed by t test. The obtained results revealed that the distance from MF (cente r of foramen mentale) to LBM (lower border of the mandible) was signif icantly bigger in males (p<0.01) than in females. There was no signifi cant difference for MF-LBM distance between I and III, I and II, II an d III male groups (p>0.05). The same findings were obtained for female s groups (p>0.05). This indicates that the MF-LBM distance is not affe cted by resorption, even the influence of postmenopausal osteoporosis could not be proved in females, as group III females were of average a ge 66.7 years and the onset of menopause is supposed to occur at 55 ye ars of age. The distance MF-LBM, is not influenced by resorption proba bly because of the functional loads from the attached masticatory musc les and, could be used in proportion to the upper part of the mandible for clinical judgment of residual bone resorption.