Takashi Satake

Ages at peak velocity and peak velocities for seven body dimensions in Japanese children

Seven body dimensions of 37 Japanese children, 16 boys and 21 girls, were measured longitudinally at 6-monthly intervals from 9 through 15 years of age. Spline curves were fitted to the longitudinal data of each dimension to obtain age at peak velocity and magnitude of peak velocity for each child. Ages at peak velocity for each dimension occurred, on average, later in boys than in girls. Mean peak velocities were also larger in boys except for chest circumference. Ages at peak velocity occurred, on average, earlier in Japanese than in European and North American children.

Adolescent spurts in body dimensions: Average and modal sequences

The sequence of growth spurts in 11 body dimensions was examined in 101 Polish adolescents, 52 males and 49 females, followed longitudinally from 11–18 years. The dimensions included weight; stature; symphyseal height; biacromial and bicristal breadths; and arm, forearm, chest, thigh and calf circumferences. Upper segment length was estimated as stature minus symphyseal height. Measurements were taken quarterly from 11–14 years, and annually or less frequently thereafter. Growth curves were fitted to individual longitudinal observations using kernel regression to derive estimates of ages at peak velocity (PV) and peak velocities. Within each sex, mean ages at PV were used to define the average sequence, while the most frequently observed sequence of PVs in individuals was used to define the modal sequence. Average and modal sequences differed, the latter probably reflecting individual variability in timing. The spurt in the estimate of leg length (symphyseal height) occurred prior to that for stature in males (first in the sequence) and was nearly coincident with that for stature in females (second in the sequence by 0.01 years). The timing of spurts in other dimensions within each sex was more variable in both average and modal sequences. Am. J. Hum. Biol. 11:287–295, 1999.

Mandibular permanent second molar with four roots and root canals: a case report

Although four-rooted mandibular first molars have been observed on a few occasions in the literature, to the best of our knowledge, four-rooted second molars have not been reported. Here, we describe a mandibular second molar with four roots and canals: two mesial and two distal. Mesial roots were separated in the cervical one-third near the cervical margin, while distal roots were divided at a lower level in the middle one-third of the root. We discuss the possibility of different root and canal variations of the mandibular second molar from a developmental point of view.

Individual variation in the sequence of ages at peak velocity in seven body dimensions

Seven body dimensions of 35 Japanese children, 15 boys and 20 girls, were measured longitudinally at six‐monthly intervals from 9 through 15 years of age. Spline curves were fitted to each dimension to obtain age at peak velocity and magnitude of peak velocity for each child. Ages at peak velocity for the seven dimensions were chronologically arranged within each individual, and the arrangement was labeled “sequence.” Kendalls rank order correlation coefficients among average and individual sequences were calculated to determine whether there was a regular order among individuals in ages at peak velocity of the seven dimensions. There were no sex differences in average sequences, but there was considerable variation among individual sequences.

Skin and subcutaneous adipose tissue weights in older Japanese determined by cadaver dissection

Forty‐six embalmed cadavers of elderly Japanese 48 to 95 years of age, 35 males and 10 females, were completely dissected, and the weights of skin and subcutaneous adipose tissue were determined. Absolute and relative skin weight in males (2.68 kg, 5.7%) were similar to those in females (2.73 kg, 6.1%). However, females had more dissectible subcutaneous adipose tissue (5.82 kg, 12.3%) than males (3.18 kg, 6.3%). These figures are comparable to dissection data obtained from embalmed cadavers in Belgium which covered a similar age range. There were statistically significant differences between Japanese and Belgians for body weight and skin weight. However, there was no difference in relative skin weight. Similar sex differences were apparent in the Japanese and Belgians. Skin and subcutaneous adipose tissue weights were significantly correlated with body weight in both sexes. Prediction equations for skin weight (SW) and subcutaneous adipose tissue weight (SATW) from body weight in Japanese are SW (g) = 0.04357 Body weight + 638.3 (r = 0.70; SEE = 386.7 g) (for males and females); SATW (g) = 0.18902 Body weight − 5837.4 (r = 0.78; SEE = 1,328.3 g) (for males); and SATW (g) = 0.36497 Body weight − 10581.5 (r = 0.79; SEE = 2,560.1 g) (for females).

Body proportion chart for evaluating changes in stature, sitting height and leg length in children and adolescents

Background: Studies by longitudinal sample to evaluate trends in stature, sitting height, leg length and body proportions together in Japanese children are scarce. Aim: Trends in stature, sitting height, leg length and LUR (lower segment and upper segment ratio) were evaluated with a graphical method (Body Proportion Chart). Subjects and methods: Longitudinal data for 520 boys and 306 girls who had 12 consecutive yearly measurements from 6.5–17.5 years of age were used. Results: Estimated growth rates of leg length were greater than those of sitting height in pre-adolescence in both sexes. Leg length was slightly longer in girls than in boys for a short period early in adolescence, but sitting height in girls exceeded that in boys for a longer period. LUR attained peak values between 12.5–13.5 years in girls (LUR = 85.7) and between 13.5–14.5 years in boys (LUR = 89.2). After attaining maximum LUR, leg length was stable, although sitting height continued to increase slightly in both sexes. Conclusion: The results highlight the usefulness of the Body Proportion Chart method for identifying changes in body proportions during adolescence.

Sexual dimorphism in the relationship between number of emerged permanent teeth and percentage of adult stature.

The relationship between the number of emerged teeth and statural growth was investigated in a sample of 31 boys and 42 girls followed longitudinally from 6–12 years of age. The number of emerged permanent teeth was counted on the total number of plaster dental casts. Percentage of adult stature attained at a given age was calculated on the basis of predicted adult stature at 25 years of age using the BTT model. Percentage of permanent teeth emerged was based upon 28 teeth, the number of all permanent teeth except for the third molars. Girls attained a greater percentage of adult stature at each age, but there was no clear sex difference in the percentage of emerged teeth. However, when expressed on the basis of %adult stature, there was clear sex difference in %emerged teeth. The results suggest a sex difference in %emerged teeth that is specific to the %adult stature that has been attained. Am. J. Hum. Biol. 11:619–626, 1999.

Plotting somatotypes using SAS/GRAPH

Plotting somatotypes is a convenient method for displaying variation in somatotype distributions. A program for drawing the somatochart and plotting somatotype data using SAS/GRAPH on the IBM mainframe is described.