BackgroundDorsal preservation is a recently popularized technique to lower the nasal dorsum without opening the cartilaginous vault. Improved nasal breathing has been reported after lowering an intact dorsum using preservation techniques, suggesting that septal deprojection opens the internal nasal valves. The goal of this study was to evaluate the effect of dorsal preservation on internal nasal valve dimensions in noses with an overprojected cartilaginous septum.MethodsTen postmortem human specimen heads with a tension nose deformity were imaged using ultra-high-resolution photon-counting detector computed tomography, after which a low-strip let-down technique was performed on each specimen. Following dorsal lowering, scans were repeated and internal nasal valve angle and area of pre- and postoperative scans were measured by three assessors. Differences in pre- and postoperative measurements were assessed using a linear mixed-effects model.ResultsA significant increase in both internal nasal valve angle (4.28 degrees, 95% CI: 3.11-5.46) and area (8.86 mm2, 95% CI: 7.11-10.61) was demonstrated after dorsal lowering. Interrater reliability among the three assessors was high, with ICCs ranging from 0.839 to 0.985.ConclusionsThis study provides morphological evidence that the internal nasal valve widens after mobilizing the dorsum and lowering the septum, without alterations to the cartilaginous vault itself. Although these results suggest that low-strip dorsal preservation may be effective in treating the functionally impaired tension nose, clinical studies are necessary to substantiate these findings in live tissue.Level of EvidenceNA Laryngoscope, 2025