Growth of the soft tissues of middle third of the face between 9 and 16 years

Abstract

The clinical applications in dentistry of three-dimensional measurement derived from stereophotography are reviewed briefly. This study is based on 306 annual life-size contour maps of the faces of 26 boys and 26 girls who were observed for varying periods between the ages of 9 and 16 years. They were all like-sexed twins in this mixed serial and longitudinal study. The following facial parameters were measured: (1) external canthus to tip of nose; (2) tip of nose to angle of mouth; and (3) angle of mouth to external canthus. Means were calculated for the different ages for boys and girls and for right and left sides. The areas of the triangles contained by the three mean dimensions were calculated for the ages 9 to 16 years. In addition to the bilateral differences, the sex differences and the pattern of growth changes and its relation to the adolescent growth spurt in the two sexes are discussed. It appears that in the middle third of the face, the right side was predominantly larger than the left and that throughout this age range, the size of any parameter was always larger for boys than girls. The growth changes throughout the age range were then compared for boys and girls and for right and left sides. The significance of the changing relationship of the means for boys and girls at corresponding ages is discussed in relation to the adolescent growth spurt. The corresponding means for right and left sides are compared as a measure of mean overall asymmetry in the normal growing face.