A lateral cephalometric study of the hard- and soft tissue profile around the face in the mixed dentition

A study was made investigate a relationship existing in the dentoskeletal framework and the soft tissue profile around the face, and compared the sexual differences between boys and girls having the normal occlusion in the mixed dentition. The lateral cephalograms were composed of 67 boys aged 10.3 years and 68 girls aged 10.4 years, respectively. By means of the lateral cephalograms, both the hard-and soft tissue structures were simultaneously analyzed, measured and evaluated by introducing the several reference items: S-N plane, palatal plane, mandibular plane, N-A line and A-P line for the dentoskeletal structures and N'-P' line for the soft tissue, and the 21 measuring points for the both structures. The significant findings were as follows: 1. In general the boys showed the larger nasal component dimension than did the girls, but the length and height of nose(N'-Prn and NA-Prn) showed the significant sexual difference among those when evaluated statistically. 2. The lip-thickness was found to be minimal in the region of nasion, greater in the region of pogonion, and much greater in the region of point A in the both sexes, but the only thickness over point A(A-A') showed the significant sexual difference statistically. 3. The upper and lower lip position were found to be located anteriorly to the esthetic line in the both sexes, but upper lip position showed the significant sexual difference when evaluated statistically. 4. The regions of nose and upper lip had a tendency not to be following the underlying skeletal profile.