Computer-aided assessment of bony nasal pyramid dimensions

Objective: To develop a computer-enabled paradigm for assessment of bony nasal pyramid dimensions. Design: Retrospective review of archived computed tomographic data. Setting: Tertiary level academic center. Patients: Patients who had undergone computed tomographic scans for computer-aided transsphenoidal hypophysectomy were included. Previous nasal surgery, inflammatory sinus disease, and documented maxillofacial trauma were exclusion criteria. Intervention: Archived computed tomographic scan images were reviewed using the software tools on a computer-aided surgical (CAS) system (StealthStation; Sofamor Danek, Memphis, Tenn). Standardized methods for the measurement of nasal bone thickness and bony nasal pyramid projection were established. Main Outcome Measurements: Bony nasal pyramid projection and nasal bone thickness were determined. Results: Computed tomographic scans from 8 patients were review-ed. Nasal bone thickness at the level of lateral osteotomy was 2.39 +/- 0.68 (mean +/- SD) mm, while nasal bone thickness at the level of intermediate osteotomy was 1.18 +/- 0.30 mm. Nasal projection from the nasomaxillary suture to the rhinion in the axial plane was 19.2 +/- 3.10 (mean +/- SD) mm, while the corresponding nasal projection at the nasion was 20.61 +/- 3.52 mm. Conclusions: This brief report presents a new paradigm for the assessment of the bony nasal pyramid. Additional normative data are necessary. This information has important implications for rhinoplasty instrument design, surgical planning, and aesthetic assessment. It is likely that computer-enabled review of archived computed tomographic images for maxillofacial assessment will become increasingly accepted. Of course, further modifications of computer technology and its specific applications are expected.