The Septum and Nasomaxillary Vault Associated with Unrepaired Unilateral Cleft Lip and Palate: A Data-Driven 3-Dimensional Model

BACKGROUND: Defining the nature of the unilateral cleft lip and palate nasal deformity and its optimal surgical correction continues to be a challenge. The purpose of this study was to develop a data-driven model of the primary unrepaired osseocartilaginous skeleton of the nasomaxillary complex. METHODS: Computed tomographic scans of 19 infants aged 3 months with unrepaired unilateral cleft lip and palate and 19 age- and race-matched controls were analyzed. Osseous landmark deviation in subjects with clefts was compared with controls. Segmentation of the osseocartilaginous septum was performed, and deformational differences were calculated between cleft and noncleft cohorts. RESULTS: Compared with controls, the rhinion, noncleft nasomaxillary junction, and cleft nasomaxillary junction deviated toward the noncleft side. The piriform margins each diverge away from midline with the noncleft side deviating lateral and superior, and the cleft side deviating lateral and posterior. These alterations result in a bony torsion with sigmoidal configuration of the cleft-side aperture, vertical shortening of the central midface, and deprojection of the nasal pyramid. Segmentation of the septum revealed anterior deviation toward the noncleft side with a single convexity toward the cleft. CONCLUSIONS: This 3-dimensional, data-driven model contradicts prior models and confirms a collapsing twist of the cleft-side aperture and medialization of the bony margin of the nasal airway with deviation of the nasal bone complex toward the noncleft side. This analysis defines the critical anatomical characteristics of the cleft nasal deformity and informs the goals of nasal correction at the time of primary repair.