Quantifying vertical and oblique distortions in panoramic radiography: A comparative analysis of dry mandible measurements

Panoramic radiography provides significant diagnostic advantages by capturing the maxilla and mandible in a single projection, offering a rapid and low-radiation imaging solution. However, inherent limitations such as magnification and geometric distortions may compromise measurement accuracy. This study quantitatively evaluates discrepancies in vertical and oblique measurements between dry mandible specimens and panoramic radiographs. Fifty-six dry human mandibles were marked with 23 metal reference points at key anatomical landmarks. Direct physical measurements were obtained using a digital sliding caliper, while radiographic measurements were derived from digital panoramic images with specialized software. Statistical analysis revealed significant differences (p < 0.05) in vertical and oblique dimensions, except in the anterior mandible. Posterior regions exhibited pronounced magnification, with vertical distortions ranging from 10% to 18% and oblique distortions from 9% to 22%. In contrast, anterior regions demonstrated minimal distortion (vertical: 6%–9%; oblique: 1%–3%). The greatest vertical magnification occurred at the mandibular ramus, while the largest oblique distortion was observed in measurements spanning the inter-incisal alveolar crest to the coronoid process. These findings indicate that panoramic radiographs provide reliable accuracy for anterior mandibular assessments but exhibit clinically relevant inaccuracies in posterior measurements, particularly in vertical and oblique orientations. This study highlights the need for caution when interpreting vertical and oblique dimensions of the posterior mandible in panoramic imaging for diagnostic or treatment-planning purposes.