Measuring the Unilateral Cleft Lip Nasal Deformity: Lateral Deviation of Subnasale Is a Clinical and Morphologic Index of Unrepaired Severity

Objective: Objective measurement of pre-operative severity is important to optimize evidence-based practices given that the wide spectrum of presentation likely influences outcomes. The purpose of this study was to determine the correlation of objective measures of form with a subjective standard of cleft severity. Design: 3D images were ranked according to severity of nasal deformity by 7 cleft surgeons so that the mean rank could be used as the severity standard. Patients: 45 patients with unilateral cleft lip and 5 normal control subjects. Interventions: Each image was assessed using traditional anthropometric analysis, 3D landmark displacements, and shape-based analysis to produce 81 indices for each subject. Main Outcome: The correlation of objective measurements with the clinical severity standard. Results: Lateral deviation of subnasale from midline was the best predictor of severity (0.86). Other strongly-correlated anthropometric measurements included columellar angle, nostril width ratio, and lateral lip height ratio (0.72, 0.80, 0.79). Almost all shape-based measurements had tight correlation with the severity standard, however, dorsum deviation and point difference nasolabial symmetry were the most predictive (0.84, 0.82). Conclusions: Quantitative measures of severity transcend cleft type and can be used to grade clinical severity. Lateral deviation of subnasale was the best measure of severity and may be used as a surrogate of uncoupled premaxillary growth; it should be recorded as an index of pre-operative severity with every cleft lip repair. The correlation of other measures evaluated clarify treatment priorities and could potentially be used to grade outcomes.