Prediction of the Age of Maximum

Puberal Growth in Body Height

A. BJoRK, D.D.S., Odont. Dr.
S. HELM, D.D.S.
Copenhagen, Denmark
The age at the onset of puberty tic department of the Royal Dental
varíes with sex, generation, population College, Copenhagen, with the special
and environment, and differs greatly purpose of examining the growth of the
from one person to another. An under face by a radiologic technique involving
standing of the relationship between the metallic implants. 2• 3 The children were
age at maximum puberal skeletal growth enrolled without regard to birthday and
and other criteria of physical matur have been examined annually. Because
ation can be of value in severa! re of the special nature of the growth
spects in connection with the care of study the number of children enrolled
the growing child, for instance, when was limited and the incidence of mal
it is desired to know whether or not occlusion in the samples is greater than
the puberal growth spurt for an in in the general population. For the
dividual has been reached or passed. present analysis thirtytwo boys and
The present analysis of longitudinally twenty girls were selected in whom ali
collected data relating to Danish chil stages of physical maturation examined
dren is limited to this specific problem: had been reached and determined. Ap
the age at maximum puberal growth proximately half of the children had
in body height is judged in relation to had sorne form of orthodontic treat
other stages of skeletal maturation, ment.
mineralization of one of the sesamoid The ages at which the stages of
bones of the thumb, two selected stages physical maturation were recorded were
of dental development, and, in girls, defined as follows:
the rnenarche, The reason for including
the sesamoids of the metacarpophalang Maximum puberal growth in body
eal joint of the thumb is that they are height (H): The age was
the only consistent ossification centers recorded midway through the annual
in the hand that appear near puberty. period during which puberal growth,
calculat ed from individual growth
curves, was greatest. The registration
METHOO
was selected as representative of the
The data for the study relate to growth of the skeleton.
Danish children of both sexes in sound
Ossification of the ulnar sesamoid
clinical health; they belong to a longi
al the metacarpophalangeal joint of the
tudinal study of facial growth being
thumb (S) : The age at onset of ossi
conducted since 1951 at the orthodon
fication of the ulnar sesamoid at the
metacarpophalangeal joint of the thumb
This investigation was supported by a
U.S.P.H.S. research grant HD 154 from was taken as six months before the
the National lnstitute of Child examination at which ossification was
Health and Human Development, National first cvident in radiographs of the right
In stitutes of Health, Bethesda, Maryland,
U.S.A., and by grants from the Danish hand. The radiographs wcre taken in
State Research Foundation. an xray ccphalostat with a focus film

134
Vol. 37, No. 2 Growth 135

Fig. 1 Radiographing the right hand

in the cephalostat.
distance of 190 cm on non-screen film;
no grid ; 60 k V ( Fig. 1). The ulnar
sesamoid (Fig. 2) is related to
the adductor pollicis muscle. The radial
sesamoid is related to the flexor pollicis
brevis muscle and on the radiographs
is usually overshadowed by the first
metacarpal, so that it is not always
visualized; it was therefore not included
in this study.
Menarche (M): The age at Fig. 2 Radiograph of the hand showing
men- arche was recorded as the the ulnar sesamoid of the metacarpo-
midpoint phalangeal joint (arrow) •
. of the chronological year of age during
which it occurred. FINDINGS

Dental stages. DS 4: Ali canines and The mean chronological ages at

premolars fully erupt- which the various stages of physical
ed. maturation occurred are given in Table
DS M2: Ali second 1, with the relevant distribution para-
molars fully erupted. meters.
These are two well-defined stages Certain departures from normality
in dental maturation around puberty. were expected. However, for none of
The classification is taken from that the stages did the distribution differ
introduced by Bjórk, Krebs and Solow.4 significantly from normality, as judged
The teeth are considered to be fully by tests of skewness and kurtosis.
erupted when they have reached the The sex differences in chronological
occlusal leve!, and the age at attain- age for the various stages of maturation
ment of these dental stages was taken can be calculated from Table l. The
to be six months before the examin- maximum puberal growth in body
ation when the criterion of the dental height occurred 18 ± 3.0 months earlier
stage was first fulfilled. This observa- in girls than in boys, and ossification
tion was made on dental casts. Cases of the ulnar sesamoid of the thumb 21
were excluded in which a dental stage ± 3.0 months earlier in girls, The sex
could not be determined because of difference in dentitional development
aplasia, or extraction of more than one was considerably smaller, full eruption
canine, premolar or first molar.
 136 Bjork and Helm April, 1967

TABLE 1
MATURATION STAGES IN YEARS AND MONTHS
Error of Standard
Mean the Mean Deviation Range
32 Boys

Max. height (H) 14-0 0-1.93 0-10.93 12-5 to 15-10

Sesamoid (S) 13-3 0-1.99 0-11.23 11-0 to 15-6
DS 4 12-11 0-3.10 1-5.54 10-7 to 16-6
DS M2 14-1 0-2.79 1-3.78 11-1 to 17-4

20 Girls
Max. height (H) 12-6 0-2.27 0-10.13 11-2 to 14-4
Sesamoid (S) 11-6 0-2.31 0-10.32 10-2 to 13-4
DS 4 12-9 0-4.14 1-6.51 10-10 to 16-4
DS M2 13-7 0-3.80 1-5.00 11-0 to 16-4
Menarche (M) 13-11 0-2.68 0-11.98 11-6 to 15-6
to the occlusal leve! of ali the canines stages of maturation are given, dis-
and premolars (DS 4) being attained tributed with respect to the years by
only 2 ± 5.2 months earlier in girls, which they preceded or succeeded the
while full eruption of ali the second year for the maximum puberal growth
molars (DS M2) was earlier in girls in body height.
by 6 ± 4. 7 months. The sex differences The sesamoid was ossified on an
were thus considerably greater for max- average 12 ± 2.1 months before max-
imum puberal growth and for ossifica- imum puberal growth for the girls and
tion of the sesamoid than for dental 9 ± 1.4 months before for the boys
development. (Table I). Individually, the ossification
These two groups of maturation either preceded or coincided with max-
stages differed also as regards the imurn puberal growth, and this relation
ranges (Table I). The ages at was the same for both sexes (Table II).
max- imum puberal growth, Onset of ossification of the sesamoids
ossification of the sesamoid, and therefore indicated that maximum pub-
menarche showed ranges of variation of eral skeletal growth was imminent or
3 - 4 years, while those for the two attained.
dental stages were nearly twice this, or The menarche occurred on an aver-
5 - 6 years. This shows that the dental age 17 ± 2.5 months after maximum
development was less strongly associated puberal growth; in sorne it fell in the
with chronologic age than the growth same year and in others later (Table
maximum, ossi- fication and II) . The menarche was therefore an
menarche. For ali the stages of indication that maximum puberal skel-
maturation the sex differences in the etal growth was attained or had been
ranges were small and insignifi- cant. passed.
The possibilities of predicting puberty The relation of the development of
can be judged both from the mean the dentition to the maximum puberal
ages at the different stages of matur- growth displayed a marked sex differ-
ation (Table I) and from individual ence (Table I). In the boys full erup-
associations between these ages (Table tion of ali the canines and premolars
II) . In this table the ages at the other (DS 4) was complete about one year
Vol. 37, No. 2 Growth 137

TABLE II
Distribution of age at ossification of the sesamoid (S), at two dental
stages (DS 4 and DS M2) and at menarche (M), in relation to the
year for maximum puberal growth in body height (H).

Max.
Years -4 -3 -2 -1 Height(H) +1 +2 +3 +4
32 Boys
s 4 17 11
DS 4 1 6 6 7 7 5
DS M2 2 3 5 11 6 3 2
20 Girls
s 1 3 11 5
DS 4 1 5 7 5 1
DS M, 3 3 8 3 2 1
M 5 6 4 5
(13 ± 3.1 months) before maximum of the girls DS M2 succeeded it, so
puberal growth, while for the girls it that these stages will provide an indi-
occurred at about the same time ( 3 cation of whether or not puberty has
± 3.8 months after). Full eruption of been attained, although a less reliable
ali the second molars (DS M2) in one than the sesamoid and the men-
the boys coincided with maximum arche.
growth ( 1 ± 3.2 months after), while
In order to study further the asso-
for the girls it was found to occur
ciation between the ages at the various
one year
stages of maturation a correlation analy-
( 13 ± 3.6 months) after.
sis was performed (Table III) after a
The ranges for the dental stages 1.n check of the form of the two-dimen-
relation to the age at the maximum sional distributions. These were tested
puberal growth (Table II) were large for departure from normality by Solow's
( 6 - 7 years) compared with those for method, 31 and no significant departures
the ossification of the sesamoid and were found.
the menarche ( 3 - 4 years). Moreover, The correlation coefficients fell into
as maximurn puberal growth fell within three, fairly well-defined groups, which
the ranges for the dental stages, these were similar for the two sexes (Table
are unsuitable as indicators of the age III) : ( 1) The ages at maximum
at maximum skeletal growth. However, puberal skeletal growth, ossification of
for most of the boys DS 4 preceded the sesamoid and menarche were cor-
maximum skeletal growth, and for most

TABLE III INTERCORRELATIONS OF

MATURATION STAGES

H/S H/M S/M DS 4/DS M.1 DS 4/H DS 4/S DS 4/M DS M.,fH DS M,IS DS M,/M
31! Boya
r1) .75 .65 .32 .31 .11 .10
20 Girls
r') .57 .49 .66 .87 .42 .35 .19 .37 .29 .20

H, age at puberal maximum in body height; S, age at ossification of the sesamoid;

M, Menarche; DS 4 and DS M2, age at occurrence of dental stages.
1) The .05, .01 and .001 significance levels are for boys: r=.35, r=.45, and r=.56,
and for girls: r=.45, r=.57, and r=.68.
 138 Bjork and Helm April, 1967
related with coefficients of between .49 consistently are the metacarpophalang-
and .75. (2) The ages at the occurrence eal sesamoids of the thumb.
of the dental stages DS 4 and DS M2
In girls the menarche likewise pro-
showed correlation coefficients of .65 vides a stage of maturation recordable
and .87. (3) The correlation between around puberty.
the ages in the two groups showed con-
sistently lower values, .10 to .42. The For the dentition, stages for evalua-
analysis thus established the presence of tion of maturation are provided by
two systems of development-a general tooth formation or eruption.'
16

physical and a specific dental one. As the magnitude of growth shows

There was no definite sex-linked dis- periodical fluctuations, evaluation of
similarity in the strength of the asso- stages of maturation can also be based
ciation between the various stages of upon the ages at which the character-
maturation. The association of age at istic changes in the rate of growth
eruption of the second molars with age occur (Fig. 3). Means and ranges of
at maximum puberal growth and age variation for the ages at the occurrence
at ossification of the sesamoid was of such stages have therefore been
considerably weaker in boys ( .11 and calculated. 3
.10) than in girls (.37 and .29), The association between the matur-
but the samples were too small to ation scale based on stages of ossifica-
establish whether this difference was tion and that based on stages of growth
real or due to sampling errors. rate has not yet been completely an-
alysed. The present study is limited to
Drscussrox an analysis of this association at puberty
Child development depends upon in- and to the possibility of predicting this
dividual variations in the magnitude time. As is evident frorn the results, the
of growth and in the time required association between ages at ossification,
to reach maturity. A characteristic of menarche and maximum rate of growth
the rnaturation process, apart frorn the is close, while these criteria are only
fact that it differs according to sex, is
that the age for the puberal growth
spurt is approximately the same for PERIODIC VARIATIONS
IN
the various parts of the body and
GROWTH RATE
organs, whereas the age when maturity
is reached is greatly differentiated.3• 34
The difficulty of establishing the stages
of rnaturation lies in the fact that there
is no exact grading, this being indicated
only indirectly. Stages of maturation . Pub.rol
mo11imurn
can be deterrnined, or at least estimated,
in severa! ways.
One way is to calculate the mean age i
for the appearance of each of the vari- i
i
ous centers of ossification or for i
epi-
•
physeal closure, and the variations in
• •
i
lnhrillt' JU'llfflllt ..........
theseº· ages. In the hand such
 1 12 28 3 35

stages are present in the first part and Ago

at the end of the maturation scale, but Fig. 3 Stages of skeletal maturation
at puberty the only centers which ossify defined by ages at periodic changes in
rate of growth.
Vol. 37, No. 2 Growth 139
weakly associated with the stages of the ossification of the round bones and
dental development. epiphyses of the hand than with the
In the present study little emphasis closure of the epiphyses of the long
is placed on means and forms of bones. They stress the importance of
distribution for the ages at which the the sesamoid as an indicator of matur-
stages of maturation occurred because ation. A close association between age
the sarnples are small and 'different at ossification of the sesamoid and arre
. o
registration methods complicate com- at máximum puberal growth in body
parison with the findings of other work- height has been mentioned in the litera-
ers. For the Danish population com- ture, but no correlation coefficients
parable data are available only for the seem to have been given. In the present
age at the menarche. 5 sample high correlation coefficients were
For skeletal growth, the sex differ- found (Table III). In more than half
ence in the mean age at maximum of the sample ossification of the ulnar
puberal growth in body height was 18 sesamoid of the thumb occurred one
± 3.0 months, which is somewhat less year before maximum puberal growth
than that usually reported.v-"" ( both sexes) ; it never occurred after
this maximum (Table II). Thus, this
The only stage of ossification analysed
stage of ossification seems to indicate
in this study was the age at ossification
fairly reliably that maximum puberal
of the ulnar sesamoid at the metacarpo-
skeletal growth is imminent or has been
phalangeal joint of the thumb. The
reached.
two sesamoids at this joint are said
19
to appear in nearly all persons, , º and
2 The mean age of 13 years and 11
thu_s not to display the inconsistency months for the menarche is close to
typical of the other sesamoids of that obtained in a representative cross-
the hand. A scrutiny of the hand sectional study in 1950 in Copenhagen
radiographs for all the subjects en- ( 13 years and 9 months). 5 In that
rolled for the implant study disclosed study a standard deviation of one year
one example of absent ossification of was calculated, but there were occasion-
the ulnar sesamoid in each sex. For al cases with the menarche as early as
a precise determination of the inci- 10 years and as late as 21, the dis-
dence of this inconsistency however tribution thus displaying positive skew-
a larger sample is required. The se; ness. The range was smaller for the
difference in ossification age for the present sample, which does not include
sesamoid was 21 months which is extreme cases. For other populations
close to that for maximum puberal the reader is referred to Tanner's
growth. A similar or somewhat greater comprehensive review of the literature.34
sex difference is given in the litera- The relation of the age at the menarche
ture.11•15·29·30 Flory " and, later, Buehl & to the age at maximum puberal growth
Pyle6 analysed the association between in body height is well documented.v-""
age at ossification of the ulnar meta- In the present series the menarche
carpophalangeal sesamoid and men- was recorded on an average 17 months
arche and gave correlation coefficients after maximum puberal growth. Since
of .75 and .71, respectively. Garn & it never occurred earlier than maximum
Rohmann15 found a coefficient of .65 puberal growth (Table II), the men-
which is close to that in the present arche is a reliable indication that the
study (Table III). The last puberal growth spurt has been reached
mentioned authors report a lower or passed.
correlation of the ossification of the The dental development was judged
sesamoid with
140 Bjork and Helm April, 1967
on the basis of two dental stages (DS 4 and the age at maximum puberal
and DS M2) , each consisting in the growth in body height has been re-
eruption to the occlusal level of all the ported, 22 as has the correlation between
teeth of a given group. Although the the age at eruption of this tooth and
dental development can be determined the age at the menarche. As illustrated
more accurately on the basis of the in Fig. 4, the sex difference in the in-
formation or emergence of the individ- tervals between occurrence of the dental
ual tooth, the group system has the stages (DS 4 and DS M2) and maxi-
advantages that the registration is simple mum puberal growth was greater ( 16
and that only a small number of well- and 12 months, respectively) than were
defined stages is in volved; the registra- the sex differences in chronologic age
tion is therefore convenient not only at occurrence of the dental stages (2
for clinical use, but also for compre- and 6 months). Neither of the dental
hensive epidemiologic studies. lt has stages was, however, of much value in
been suggested that the age of eruption predicting puberty, since the ranges
is more dependent on environmental included the puberal growth spurt, but
factors, such as loss of teeth and DS 4 in boys and DS M2 in girls pro-
crowding, than is tooth formation.17 •24 vide sorne guide in this respect. On the
The effect of loss of teeth was elimin- basis of data from the literature7 •22,27
ated to sorne extent by choosing criteria Tanner34 has found the eruption of
of dental development based on the sorne of the teeth more closely related
eruption of groups of teeth instead of to puberty in girls than in boys. The
individual teeth, but the influence of higher correlation between DS M2 and
premature loss of deciduous molars other criteria of puberty in girls than
could not be assessed, 10 nor could the in boys in the present samples (Table
effect of crowding or orthodontic treat- 111) bears out this view, but confirma-
ment. The ages for the dental stages tion in larger samples is needed.
(DS 4 and DS M2) are not directly
It has been shown clearly by Moor-
comparable with those for the eruption rees et al. 23·25 that the dental arch
of the individual teeth, which are usual- dimensions and the space conditions
ly - given as the mean age for the during development are considerably
emergence through the gum of homo- more strongly associated with dental
logous teeth of each jaw. 7 •8 The small age than with chronologic age. On
sex difference in age at occurrence of the other hand, it is established that
DS M2 (6 rnonths) is consistent with around puberty growth of the face and
the value usually given for the sex jaws closely follows the same matur-
difference in age at formation and ation scale as general skeletal growth,
emergence of the second molars in represcnted by body height. 3,26
each jaw.7 •8•13• 14• 17 The mean age at
DS M2 in particular may have been It may therefore be of practica! im-
slightly higher in the present samples portance in clinical orthodontics to be
than in the population. able to assess the development of the
various systems of maturation. Since
That the sex difference is smaller growth in body height is the dimension
Ior dental development than for "skel- by which maximum puberal skeletal
etal age", expressed as the degree of growth is most easily determined,
ossification, has been shown in many measurement of the annual growth
studies, and particularly clearly by in body height is recommended as a
Garn et al. 13 The correlation between routine procedure in orthodontic cases
the age at eruption of the second molars treated over a long period. Where such
Vol. 37, No. 2 Growth

MATURATION STAGES AT PUBERTY

CM/YEAR
 /ó
141

9 10 11 12 13 14 15 16 17 18
AGE IN YEARS
Fig. 4 Sex differences in mean ages at physical stages of maturation at puberty,
marked off on the growth curves for the two sexes.
H, maximum puberal growth in body height; S, ossification of the sesamoid; M,
menarche; DS 4 and DS M�, dental stages.
longitudinal data are not available, and this complicates the prediction of
radiologic examination of the ossifi- residual growth. 8
cation of the ulnar sesamoid of the
thumb may provide a guide with the SUMMARY
reservation that, in single cases, ossifi-
The possibility of predicting the age
cation may possibly not occur. This
at maximum puberal growth in body
indicator of maturation has two ad-
height from other criteria of matura-
vantages: its observation <loes not de-
tion has been evaluated on a longitud-
pend on a longitudinal technique, it
inal basis. The study was performed on
is easily recorded on a dental film.
twenty girls and thirty-two boys, all
In girls, routine registration of the
Danish.
menarche may be of great value. Dental
maturity in the years around puberty There was a close association between
may be judged with the simplified the age at maximum growth in body
criteria DS 4 and DS M2. height and the age when ossification
of the ulnar metacarpophalangeal sesa-
It should be pointed out that while moid of the thumb occurred, and also
maximum puberal growth occurs at in girls, the age at the menarche. The
approximately the same time for the sesamoid <lid not ossify after maximum
upper face, the mandible and body puberal skeletal growth, and it usually
height, growth ceases at different ages, ossified one year before; conversely,
142 Bjork and Helm April, 1967
the menarche <lid not occur before this 7. Clements, E., Davies-Thomas, E., and
age, and it was recorded up to a few Pickett, K. Time of eruption of
per- manent teeth in British
years later. The dental development, children in
on the other hand, was of little value 1947-8, Brit. med. J., 1: 1421-4, 1953.
as a criterion of puberty, since the 8. Degerbel, M. Om tandskiftets forleb
eruption to the occlusal level of all the h e s Kebenhavnske kommuneskole-
bern. Med henblik pa tandskiftet hos
canines and premolars ( DS 4) , es- de evr ige primater, Medd.
pecially for the girls, and eruption to Dammarks Antropologi, Ill: 237-327,
1931.
the occlusal level of all the second
9. Deming, J. Application of the Gom-
molars (DS M2), especially for pertz curve to the observed pattern
the boys, could occur several years of growth in Iength of 48
before or after maximum puberal individual boys and girls during the
adolescent cycle of growth, Hum.
skeletal growth. Biol., 29: 83-
lt was concluded that . in clinical 122, 1957.
orthodontics both skeletal and dental 10. Fanning, E. Effect of extraction of
deciduous molars on the formation
maturation should be registered. lm- and eruption of their successors,
portant criteria of maturation at pub- A ngle Orthodont., 32: 44-53, 1962.
erty are: the age at maximum puberal 11. F'lory, C. Osseous development in
growth in body height, the age at ossi- the hand as an index of skeletal
development, Monogr. Soc, Res. Child
fication of the ulnar sesamoid of the Develop., Vol. 1, No. 3, 141 pp., Com-
thumb, and, in girls, the age at the mittee on Child Develop., Univ. Chi-
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12. Francis, C. The appearance of cen-
tion around puberty that display a ters of ossification from 6 to 15
weaker association are two dental stages, years, Amer. J. Phys. Anthrop., 27:
DS 4 and DS M a- 127-38, 1940.
13. Garn, S., Lewis, A., Koski, K., and
Royal Dental College Polacheck, D. The sex difference in
tooth calcification, J. Dent. Res., 37:
561-67, 1958.
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