W. R. K. Perizonius
Institute of Human Biology, State
University of Utrecht, Achter de Dora
24, 3512 JP Utrecht, The Netherlands
Received 25 August 1983 and
accepted 15 October 1983
Keywords:
cranial suture closure,
age estimation, paleedemography,
reference collection.
Closing and Non-closing Sutures in 256
Crania of Known Age and Sex from
Amsterdam (A.D. 1883--1909)*
By dividing a Dutch reference collection into two subsamples of different
ages, remarkable differences were found in the suture closure process in
these subsamples. Spearman rank correlations demonstrated that mean
endocranial closure stage is correlated (P < 0.001) with age in the ages
below fifty but not in tEe ages above fifty. In the latter ages the closure stage
of individual suture sections showed positive as well as negative correlations
(0'001 ~< P < 0.05) with age at death. Therefore two different suture
closure indices were introduced as age indicators, one for each subsample.
Both indices are correlated (P < 0"001) with age within their subsample. It
is supposed that the required division into subsamples may be realized with
the help of other age indicators. As possible age indicator, especially when
used together with others in "complex methods", suture closure has not yet
served its turn.
1. Introduction
The methods to estimate the age at death of human skeletal remains are still unsatisfactory.
Old ages especially pose a problem. One of the most discussed age estimators has always
been cranial suture closure. Even nowadays its supporters and opponents can easily be
found. On the one hand there are the "Recommendations for age and sex diagnoses of
skeletons" (Workshop of European Anthropologists, 1980) accepted at the International
Conference on Paleodemography in Sarospfitfik, Hungary (1978), which recommend the
"complex method" of Nemesk&ri
et al.
(1960) for age diagnosis of adults. This "complex
method", also described in AcsAdi & Nemesk~ri (1970), combines [bur age indicators, one
of them suture closure. On the other hand there are the critics: Singer (1953), Erank6 &
Kihlberg (1955), Brooks (1955), Genovfis & Messmacher (1959), Powers (1962) and more
recently Masset (1971). The last article entitled: "Erreurs syst~matiques dans la
d~termination de l'~ge par les sutures cr~niennes" finally led to the more general article:
"Farewell to paleodemography" (Bocquet-Appel & Masset, 1982). Here it is frustratedly
stated that "After devoting a few years to this young possibly still-born science, the authors
bid farewell to paleodemography".
In this study a not discouraged author renders an account of the still existing obligation
to investigate possible age estimators in every unique reference collection. No general
statements about the vitality of paleodemography will be found. The article is confined
simply and solely to the relation between suture closure and age at death as it is found in
256 crania of known inhabitants from Amsterdam who died between 1883 and 1909.
Science, even paleodemography, will proceed continuously. Still-born sciences do not
exist. Only when all problems are solved may one bid farewell. The search for age
estimators will continue until they are found.
* Supported by grant no. 28-93 of the Netherlands Organization for
the Advancement of Pure Research (Z.W.O.).
Journal of Human Evolution
(1984) 13, 201-216
0047-2484/84/020201 + 16 $03.00/0 9 1984 Academic Press Inc. (London) Limited
202
w.R.K. PERIZONIUS
2. Material
Skeletal remains of known age and sex are scarce. There are but a few collections available
in Europe. The Amsterdam crania, housed at the Laboratory of Anatomy and Embryology
of the Municipal University of Amsterdam, form the only Dutch collection of this kind. It
consists of dissection material collected in the period A.D. 1883--1909 and involves
non-Jewish inhabitants of Amsterdam born in almost all parts of the Netherlands. Name,
age, sex, stature and sometimes cause of death are known from the records. According to de
Froe (1938), who investigated the relation between cranial measurements and age and sex
on this material, it is a rather homogeneous collection (small coefficients of variation for
cranial length and cranial breadth). Only the crania of adults (20 years and older) and
those without pathological deformations were used. For the age and sex distribution of the
256 examined crania see Table 1.
Table 1 The distribution of 256 Amsterdam crania according to age and sex
Age-group
20-29 30-39 40-49 50-59 60-69 70-79 80-89 90-99 Total
Males 2 4 20 34 47 50 17 -- 174
Females 3 5 6 14 20 24 8 2 82
Total 5 9 26 48 67 74 25 2 256
3. Methods
In order to be able to compare the data from this study with those of Acs~idi & Nemesk&ri
(1970) it was desirable to use identical methods. Personal communication with one of the
authors (Nemesk~ri) made it possible to copy their methods almost exactly (when
Nemesk~ri scored a selected sample of 79 Amsterdam crania no significant inter-observer
difference in mean endocranial closure stage was found, P < 0"001).
The obliteration of the sutures was ascertained endocranially as well as ectocranially. In
both cases the degree of ossification was scored in 16 parts of the three main cranial sutures
(Figure 1) as has been done by Acs~idi & Nemesk~ri (1970).* The coronal suture was
divided in three parts on the right side (Clr, C2r,
C3r)
and three parts on the left side (C11,
Cul, C31), the sagittal suture in four parts (S1, $2, $3, $4) and the lambdoid suture again in
three parts on the right (Llr, L2r, L3r) and on the left side (LI 1, L21, L31). Ectocranially the
different sections can be distinguished by differences in the character of the suture (Figure
2). Endocranially the sutures do not show these differences in character. Consequently the
endocranial sutures are simply divided in sections of equal length.
The scale of ossification (0, 1, 2, 3, 4) used by Acsfidi & Nemeskdri (1970) was based on
the classification presented by Martin &Saller (1957-1966). Because of the fact that in
Acsfidi & Nemesk&ri (1970) the description of these five stadia is rather simple (0 = open,
1 = incipient closure, 2 = closure in process, 3 = advanced closure, 4 = closed) more
details of their definitions (personally communicated to the author by Nemesk~ri) are
presented here (Figure 3).
* The "Recommendations for age and sex diagnoses of skeletons"
(Workshop of European Anthropologists, 1980) incorrectly states 14
sections instead of 16.
CLOSING AND NON-CLOSING SUTURES
203
Figure 1. Schematic representation of
the 16 endocranial, and 16 ectocranial
sections in which suture closure was
scored.
Inner aspect of the skull
Right Left
~ronal sut~
Sagittal
suture
ambdoid I L3L ]
suture '
Endocronial suture closure
Upper aspect of the skull
Right ..... Left
Lomoaola
IL, r f
~ Sogittal
SUtUre
C' r I0' 1
~ suturel C3L I
Ectocranial suture closure
Figure 2. The ectocranial sections
corresponding with differences in the
character of the sutures (drawing after
Oppenheim, 1907).
Upper aspect of the skull
~2 L3
Lambdoid suture
L3
r
Right ~ -~ Left
~2 ~eut-ur s~ ~ S~
In imitation of Nemeskfiri endocranial suture closure was observed by means of a small
lamp put through the foramen magnum. In case of impossibility to inspect completely the
endsections of the coronal and/or lambdoid suture through the foramen magnum, the
closure stadium of the most lateral part that could still be observed was taken instead.
Mean ectocranial as well as endocranial closure stages were calculated for the three main
sutures by adding the scored closure stages of the different sections and dividing the result
by the number of sections (six or four) which compose the suture in question. Endocranial
closure indices were calculated in the same way, adding the closure stages of all the
endocranial sections and dividing the result by 16.*
* The statement in Acsfidi & Nemesk&ri (1970) that this index had been
determined from averages of the individual sutures, is incorrect.
204
w.R.K. PERIZONIUS
Figure 3. Description of the five stages of suture closure.
Stage O. Open suture. There is still a little space left
between the edges of the adjoining bones.
Stage 1. Suture is closed, but clearly visible as a
continuous, often zigzagging, line.
Stage 2. Suture line becomes thinner, has less zigzags
and may be interrupted by complete closure.
Stage 3. Only pits indicate where the suture is located.
Stage 4. Suture completely obliterated, even its loca-
tion cannot be recognized.
,..,
Q. 9 9 o = 9
o
To estimate the possible relation between suture closure and age at death Spearman
rank correlation coefficients (one tailed) were calculated. Because of the considerably
skewed age distribution of the sample (see Table 1), Pearson correlation coefficients are
less appropriate.
4. Results
In order to know whether the two sexes could be treated together, which has the advantage
of larger samples, it has first been investigated ifa significant sex difference in the speed of
the ossification process of the cranial sutures could be found. To that purpose the mean
closure stages of the three main sutures in different age classes of ten years each were
compared. Ectocranial and endocranial closure stages for males and females are presented
in Tables 2 (a,b) and 3 (a,b) respectively. Student t-tests demonstrated no significant
(P I> 0"05) differences between the mean closure stages for males and the comparable
means for females. This is in agreement with the findings ofAcs/tdi & Nemesk6ri (1970).
Consequently both sexes were treated together from this moment onward.
Table 2(a) Mean ectocranial closure stages of the three sutures in males
Mean ectocranial closure stage
Age (years) n
Cr Coronal suture Sagittal suture Lambdoid suture
20-29 0.92 s.d. 1'06 2'50 s.d. 0.71 1'25 s.d. 0'35 2
30-39 2.08 1-11 3.56 0"72 1"58 1.20 4
40-49 2'33 1'61 2"90 0'72 1"82 0"85 20
50-59 2.68 0"62 3-04 0'84 2-28 0-87 34
60-69 2'54 0'79 2"76 0.86 1.78 0"86 47
70-79 2"89 0"53 3.21 0'66 2"22 0"75 50
80-89 2"79 0-49 2-91 0-63 1-75 0.80 17
90-99 .......
CLOSING AND NON-CLOSING SUTURES 205
Table 2(b) Mean ectocranial closure stages of the three sutures in females
Mean ectocranial closure stage
Age (years) n
Coronal suture Sagittal suture Lambdoid suture
20-29 1"28 s.d. 0'63 1"08 s.d. 0'76 0'83 s.d. 0"83 3
30-39 1'87 0-87 1"75 0"43 1"20 0"76 5
40-49 2"92 0'65 2"83 0"86 1"78 1"34 6
50-59 2'45 0'83 2"27 1'02 1"74 0'99 14
60-69 2"88 0'57 2"96 0"68 2"18 1"13 20
70-79 2'71 0'74 2'76 0'79 1"75 1"10 24
80-89 2"75 0"68 2"69 0"85 1-75 1-26 8
90-99 2'33 0'24 2"25 0'71 0"92 0"59 2
Table 3(a) Mean endocranial closure stages of the three sutures in males
Mean endocranial closure stage
Age (years) n
O ~ Coronal suture Sagittal suture Lambdoid suture
20-29 0"50 s.d. 0.24 1.50 s.d. 0.00 1.08 s.d. 0"12 2
30-39 2.49 1-61 3.06 1.03 1'54 0'90 4
40-49 3-52 0-63 3.35 0-63 2.70 1 03 20
50-59 3-73 0-58 3.54 0-44 3"05 0"78 34
60-69 3"56 0-97 3.43 0.84 2.89 0.83 47
70-79 3"92 0' 17 3'58 0"31 3"30 0'44 50
80-89 3-72 0'50 3.43 0"39 2-99 0'80 17
90-99 ......
Table 3(b) Mean endocranial closure stages of the three sutures in females
Mean endocranial closure stage
Age (years) n
Coronal suture Sagittat suture Lambdoid suture
20-29 1-67 s.d. 1.20 1.50 s.d. 0.66 0.94 s.d. 0.82 3
30-39 2-40 1-01 2.70 0.74 1.23 0.98 5
40-49 3.86 0.34 3.58 0.30 2.75 0.98 6
50-59 3-48 1.11 3.38 0-89 2.57 1.05 14
60-69 3.80 0.42 3.60 0.31 3-08 0.72 20
70-79 3-79 0.61 3.64 0.49 2.48 1.04 24
80-89 3.92 0.13 3.47 0-31 2-42 1-03 8
90-99 3.75 0.35 3.38 1.18 1.33 0.47 2
In Table 4 (a,b) the mean ectocraniat and endocranial closure stages of the coronal,
sagittal and lambdoid sutures in the successive age-groups are presented. It is obvious that
the mean closure stages do increase up to a certain age-group only [indicated in Table 4
(a,b) by a plus]. The phenomenon occurs in each suture ectocranially as well as
endocranially. The age-groups concerned are 40-49 years (once), 50-59 years (three
times) and 70-79 years (twice). Moreover, from the age-group of 70-79 years onward
[marked in Table 4 (a,b) by a minus] the degree of ossification diminishes in all three
sutures ectocranially as well as endocranially. Suture obliteration seems to be correlated
with age up to a certain age only. Even the possibility of a negative correlation in the higher