Three-dimensional computed tomographic analysis of the primary nasal deformity in 3-month-old infants with complete unilateral cleft lip and palate

The purpose of this study was to analyze the geometry of the primary cleft lip nasal deformity dimensional computerized tomography in a group of 3-mon th-old infants with complete unilateral cleft lip and palate before surgica l intervention. Coordinates and axes were reconfigured after the three-dime nsional image was oriented into neutral position (Frankfurt horizontal, tru e anteroposterior, and vertical midline). Display and measurement of skin s urface and osseous tissues were achieved by adjusting the computed tomograp hic thresholds. S-N, N-ANS, S-N-O, and S-N-ANS were measured from true late ral views. Biorbital (LO-LO), interorbital (MO-MO), intercanthal (en-en), a nd nasal (al-al) widths were measured from the anteroposterior view. The bo ny alveolar cleft width was measured from the inferior view. The study grou p was divided into two groups on the basis of skeletal alveolar cleft width : six patients with clefts narrower than 10 mm and six patients with clefts wider than 10 mm. Only the S-N-ANS angle differed between the two groups, i.e., it was greater in the group with the wider clefts (p < 0.05). Coordin ates of six landmarks at the base of the nose [sellion (se), subnasale (sn) , cleft-side and noncleft-side subalare (sbal-cl and sbal-ncl), and the mos t posterior point on the lateral piriform margins (PPA-CL and PPA-NCL)] wer e obtained for analysis of the nasal deformity. On average, the subnasale p oint was anterior to sellion and deviated to the noncleft side; the cleft-s ide sbal point was more medial, posterior, and inferior than the noncleft-s ide sbal point; and the PPA point on the cleft-side piriform margin was mor e lateral, posterior, and inferior than the PPA point on the noncleft side. These discrepancies were nor universally observed. However, in all patient s, four findings were observed without exception (p < 0.01): (1) subnasale (sn) was deviated to the noncleft side (mean distance from midline, 5.0 mm; range, 2 to 9.5 mm), (2) the cleft-side alar base (sbal-cl) was more poste rior than the noncleft-side alar base (sbal-ncl) (mean difference, 3.6 mm; range, 1 to 5.5 mm), (3) the noncleft-side alar base (sbal-ncl) was further fi om the midline that the cleft-side alar base (sbal-cl) (mean difference in lateral distances of sbal-ncl and sbal-cl from the midline, 2.8 mm: ran ge, 0.5 to 7 mm), and (4) the cleft-side piriform margin (PPA-CL) was more posterior that the noncleft side piriform margin (PPA-NCL) (mean difference , 2.1 mm; range, 0.5 to 4 mm). In conclusion, the nasal deformity in unilat eral cleft lip and palate that has not been operated on is characterized by these foul features and increased S-N-ANS angle with increased alveolar cl eft width.