Objective: The purpose of this study was to analyze the three-dimensional configuration of the premaxilla, vomer, and lateral segments in bilateral cleft lip and palate (BCLP) infants and to investigate the early changes in the configuration following one- and two-stage cheiloplasty.
Methods: This study consisted of 10 complete BCLP infants. One-stage operations were performed in five patients according to Manchester's method at 4 months of age. Two-stage operations were done for the remaining five patients using a triangular flap according to Tennison's method, at 4 and 8 months of age. Serial plaster models before and after the cheiloplasty were measured with a computer-controlled, highly accurate, contact-type measuring apparatus. Temporal changes in the configuration and form of the premaxilla were observed using an automatic superimposition method. The inclination and deviation of the vomer were evaluated using an approximation technique to a straight line with least squares. The distance between the lateral segments and a three-dimensional coordinate of the incisal point were also measured.
Results and conclusions: The following differences in palatal configuration between the one- and two-stage cheiloplasties were observed: 1) In the two-stage group, the premaxilla shifted toward the cleft edge where the cheiloplasty was performed in both first- and second-stage operations. After the two-stage operation, the premaxilla did not shift greatly, and the premaxilla in cases 4 and 5 shifted downward and toward the cleft edge of the lateral segments where the first operation was performed. Protrusion of the premaxilla remained in the two-stage group. 2) In the one-stage group, the premaxilla in case 4 descended downward and backward without twisting or bending. The premaxilla of the other patients descended downward with twisting and bending. 3) Patients in the two-stage group had a stronger tendency toward medial collapse of the lateral segments than did those in the one-stage group.