Objective: The purpose is to evaluate the correlation between the changes of soft and hard tissue after advanced Lefort I osteotomy in patients with complete unilateral cleft lip and palate.
Methods: Lateral cephalometric films were taken from before and after operation. The same landmarks in two films were compared horizontally and vertically. The correlation ratio between changes of soft and hard tissue were analysed statistically.
Results: After operation, the length of upper lip of the patients with CLP increased. The ratio between the movement of upper incisor and upper lip was 0.77 horizontally and 0.67 vertically, respectively.
Conclusion: The slope between hard and soft tissue was treated as ratio. It is more significant than the horizontal difference between soft and hard tissue, since correlative factor was contained in the slope.