The aim of this study was to evaluate the variation of the anatomical landmarks at interforaminal region with age and dental status by examining spiral computed tomographies. Fifty young (≤40) and 50 older (>40) patients’ interforaminal regions were evaluated with spiral computed tomographic images. In both age groups, 25 of the patients were fully dentate up to mandibular bicuspids contralaterally and the rest were completely edentate at interforaminal region including mandibular bicuspids. The distances between mental foramen to alveolar crest (MF-AC), mental foramen to lower cortex (MF-LC), mental foramen to lingual external border (MF-LEB), mental foramen to contralateral mental foramen (MF-MF), and the height (HMF) and width of MF (WMF) and anterior loop of mental foramen (ML) were measured by an experienced calibrated clinician. In spiral computed tomographic images, MF-AC and MF-LC were significantly lower in edentate subjects being independent of age (p<0.001). WMF and HMF were found significantly smaller in both older and edentate subject groups (p<0.01), MF-MF was significantly longer (p<0.001) in both edentate and older patients, and MF-LEB was not affected by age or dental status (p>0.05). The anatomical landmarks at interforaminal region more likely depend on dental status rather than the age. Safety zone should be 3 mm far from MF for dental implant placement in interforaminal region as the anterior loop of mental foramen was measured as approximately 3 mm.
Keywords: Dental implants, interforaminal region, mental nerve, spiral computed tomography
