Morphological and morphometric characteristics of the nasopalatine canal in dentate and completely edentulous patients: a cone-beam computed tomography cross-sectional study.

BACKGROUND: Anatomical changes associated with tooth loss may alter the morphology and dimensions of the nasopalatine canal, potentially affecting implant planning. However, comparative evidence between dentate and completely edentulous maxillae remains limited. This study aimed to evaluate and compare the morphological and morphometric characteristics of the nasopalatine canal and the anterior bone region in dentate and completely edentulous patients via cone-beam computed tomography (CBCT). METHODS: Cross-sectional CBCT analysis was performed on 108 patients (54 dentate maxillae and 54 completely edentulous maxillae). Morphometric parameters of the nasopalatine canal and the bone anterior to the canal were measured in the axial, sagittal, and coronal planes. Interobserver reliability was assessed via intraclass correlation coefficients (ICCs) and Cohen's kappa. Intergroup comparisons were conducted via regression models adjusted for age and sex. RESULTS: Compared with the completely edentulous group, the dentate group presented a significantly greater nasopalatine canal length (mean difference: 1.66 mm; 95% CI: 0.42-2.90; p = 0.009), whereas canal angulation was smaller (-6.47°; 95% CI: -9.93 to -3.00; p < 0.001). On sagittal images, the middle and inferior canal widths were significantly smaller in the dentate group (ratios of means: 0.79 and 0.80; p < 0.001), whereas the superior width was not different. Similarly, on axial views, the middle and inferior horizontal canal widths were reduced in the dentate group. The bone region anterior to the nasopalatine canal in the dentate individuals presented greater buccal crestal length (4.66 mm; p < 0.001) and greater bone width at 1 mm and 6 mm apical to the crest (ratios: 1.65 and 1.24; p < 0.001). Morphologically, the Y-shaped canal configuration predominated in dentate patients (51.9%), whereas the single-canal configuration was more common in the completely edentulous group (64.8%). On the sagittal plane, cylindrical morphology was significantly more common in dentate individuals [odds ratio (OR) = 3.68; 95% CI: 1.56-9.00]. CONCLUSIONS: Completely edentulous patients exhibit wider and more angulated canals but reduced canal length and anterior bone volume.