In this study the effect of the growth and development on soft tissue profile of preadolescent subjects with normal occlusion, skeletal class 1 and mesiodivergent structure was investigated. 10 girls, the mean skeletal age being 9.28 ± 1.58 years and 10 boys, the mean skeletal age being 9.88 ± 1.80 years were selected. Two standardized laterel cephalometric roentgenographs were taken from all subjects at one year interval. The angular and linear measurements were performed on tracing films. The mean values of these measurements were calculated and statistically evaluated. According to statistical evalu­ation, the growth and development of the lips and soft tissue chin in both girls and boys were normal and they were in harmony with each other. Howeever in girls the increase of lower lip thickness and in boys the changes of hard and soft tissue pogonion positions were found to be statistically insignificant. In girls, the correlations between the upper lip position and maxillary growth; soft tissue pogonion and mandibular growth, lower lip position and upper incisor position; lower lip position and overbite were found to be significant; In boys the correlations between upper lip position and maxillary growth; upper lip position and upper incisor position; lower lip position and mandibular growth; lower lip position and lower incisor position were found to be significant. In all subjects a high correlation is found between hard and soft tissue pogonion.

Keywords: Soft-Tissue Profile, Growth and Development, Normal Occlusion