Dentition and dental arch dimensions in British children at the age of 212 to 3 years

Archs oral Bid.

Vol. 14, pp. 1031-1040, 1969. Pergamon

Press. Printed in Gt. Britain.

DENTITION AND DENTAL ARCH DIMENSIONS IN BRITISH CHILDREN AT THE AGE OF 24 TO 3 YEARS T. D. FOSTER, M. C. HAMILTON and C. L. B. LAVELLE University of Birmingham Dental School, Birmingham, England Summary-Measurements were made of the dentition and the dental arches of 50 male and 50 female white British children in the age range 2: to 3 years. For all dimensions of the dentition and dental arches the measurements on the males were larger than those on the females, with the exception of the distance between the distal surfaces of the lower central incisors. The differences between the sexes were often statistically significant. A high degree of correlation was found between the size of the dentition and the size of the dental arch in both sexes. It is suggested that this may be one of the reasons for the low degree of prevalence of crowding of the primary dentition. MANY studies have been made of the dimensions of the teeth and dental arches in the primary dentition but only a few have been made on British children. Furthermore, little information exists on the size of the dental arches at the stage of completion of eruption of the primary dentition, or of the relationship between dentition size and dental arch size at that stage. COLYER (1920) measured dental arch dimensions on three children during the growth period and compared the arch of the primary den&ion with that of the permanent dentition. CHAPMAN (1935) measured dental arch breadth on plaster casts of a number of children, including 71 under the age of 3 years, all selected as having “normal occlusion” of the teeth. More recently, CLINCH (1951) measured plaster casts of 61 children between 3 years and 8 years of age and reported on the changes which occurred in the length and breadth of the arch. She did not, however, give any actual measurements of the arches. As far as measurement of the primary dentition is concerned, little information is available relating to British children. CLINCH (1963), studying the relationship between the mesiodistal diameters of the primary teeth and their permanent successors, gave measurements of the full primary den&ion of 65 British children. Measurements of the primary dentition and dental arches of other ethnic groups, notably North American and Scandinavian, have been well-documented. Reports have been made of dental arch measurements on North American children by LEWIS and LEHMAN (1929), COHEN (1940), HOLCOMB and MEREDITH (1956), MEREDITH and HOPP (1956) and MOORREES (1957), among others. Measurements of primary teeth of North American children have been made by MOORREESet al. (1957), (1959) and COUGHLIN (1967). SEIPEL (1946) studied

both dentition

on primary teeth in Scandinavian children. 1031 A.O.B. 14/9-c

and dental

arch dimensions

1032

T. D. FOSTER,M. C. HAMILTONAND C. L. B. LAVELLE

In order to provide more information on dentition and dental arch dimensions in British children at the stage of completion of the primary dentition, a study was undertaken to investigate in particular, (a) sex differences in tooth size and dental arch size, (ZJ) the relationship between dentition size and dental arch size. MATERIALS

AND

METHOD

One hundred white British children, 50 males and 50 females, in the age range 29 to 3 years, were the subject of this study which formed part of a larger growth study. The names of the children were selected from lists of all children born within 10 specified areas of the City of Birmingham. The 10 areas included 3 from the inner wards, 4 from the middle wards and 3 from the outer wards of the city. The selection was made on the basis of birth date only, all children born within a specified month being chosen. The parents of the children so selected were invited to attend with their children for assessment. The acceptance rate to the invitation was only 18 per cent but no common factor could be found among those who accepted. Eighty per cent of the children were free from dental caries. It is believed that in the main the acceptance was made from a desire for the child to receive regular dental attention. Impressions of the upper and lower dental arches were taken from each child, using alginate base hydrocolloid impression material. Models were cast in dental stone-plaster and were photographed in a standard position with the occlusal plane parallel to the photographic plate, together with a standard reference scale. All measurements of the teeth were made on the plaster casts. Measurements of the dental arches were made on the photographic negatives of the occlusal surfaces of the plaster casts, any magnification of the image being corrected by reference to the standard scale. Thus, the arch measurements were made easier being made on a flat surface rather than on the plaster casts. All measurements were made with the use of vernier calipers, reading to the nearest O-1 mm. The measurements of the teeth and of dental arch length were made on the left side of the jaw only, according to anthropological convention. The following measurements were made :

(1) Dentition (a) Mesio-distal crown diameter: The maximum distance between the mesial and distal surfaces of the crown, parallel with the occlusal plane. (b) Bucco-lingual crown diameter: The maximum distance between the buccal and lingual surfaces of the crown at right angles to the mesio-distal crown diameter and parallel to the occlusal plane. (c) Crown height: On molars, the vertical distance between the tip of the mesiolingual cusp and the free gingival margin. On incisors and canines, the vertical distance between the lowest point of the free gingival margin on the labial surface of the tooth

DENTITION AND DENTAL ARCH DIMENSIONS IN BRITISH CHILDREN

1033

and the occlusal tip of the tooth. Although this measurement can be altered by occlusal attrition or gingival recession, it was considered that at the age of 2+3 years such attrition and recession would be minimal. (d) Total dentition size: The total dentition size was computed as the sum of the mesio-distal tooth diameters. (2) Dental arch Five measurements of dental arch width (Fig. 1) and seven measurements of dental arch length (Fig. 2) were made. (a) Dental arch width. Measurements were made between each tooth and the corresponding tooth on the opposite side of the arch. In each case the dimension of the arch width was computed as the mean of the distance between the two most lateral

FIG.

1. The

measurements

of

the dental computed

arch widths.

FIG. 2. The measurements

each position

the width

was

0

ir 0

At

as x + y/2.

of the dental arch lengths. All measurements left side of the arch.

were made on the

1034

T. D. FOSTER,M. C. HAMILTON AND

C. L. B. LAVELLE

points and the distance between the two most medial points on the teeth concerned. This was thought to obviate discrepancies due to individual tooth rotations. (b) Dental arch length. The measurements were made from the mesial aspect of the anterior tooth to the distal aspect of the posterior tooth in each case. (i) 1st incisor to 2nd incisor. (ii) 1st incisor to canine. (iii) 1st incisor to 1st molar. (iv) 1st incisor to 2nd molar. (v) Canine to 1st molar. (vi) Canine to 2nd molar. (vii) 1st molar to 2nd molar. (c) Total arch length. The total arch length was measured in segments as a line passing from the distal surface of the second molar to the mesial surface of the first incisor and passing through the mid points of the occlusal or incisal surfaces of each tooth. (Fig. 3)

0

FIG. 3. The measurements of total arch length.

(3) Total spacing Total spacing was assessed as the difference between dentition size and arch size. This does not take into account the space between the central incisors. As a check on accuracy of measurements, 10 male and 10 female plaster casts and photographs were each measured ten times. In addition, the dental arch measurements on the photographs were compared with similar measurements on the plaster casts. Analysis of variance showed that the error of the measurements was statistically insignificant (P > 0.2). RESULTS

The results are shown in Tables 1, 2 and 3. (1) Dentition Table 1 shows the mean figures for the dimensions of each tooth in the primary dentition of 50 males and 50 females, together with the standard errors of the means.

DENTITION

AND

TABLE

1. MEAN

50

MALES

AND

DENTAL

ARCH

VALUES

50

DIMENSIONS

OF DIMENSIONS

FEMALES

IN THE

IN BRlTlSH

OF PRIMARY

AGE RANGE

2+

TO

1035

CHILDREN

TEETH

3

OF

YEARS

Male

Female

Mesio-distal* Bucco-lingual Crown Height*

S.E. Mean 0.680 + 0.004 0.526 f 0.006 0.532 + 0.007

Mean S.E. 0.627 f 0.008 0.516 + 0.012 0.506 + 0.007

2nd Incisor Mesio-distal* Bucco-lingual Crown height

0.553 + o-005 0.457 * 0.004 O-472 + 0.007

0.513 + 0.009 0.448 k 0.010 0.468 2 0.010

Canine Mesio-distal* Bucco-lingual Crown height

o-743 & 0.004 O-643 f O-005 0.588 + O-006

0.704 * 0.013 0.615 f 0.009 0.566 k 0.010

Mesio-distal Bucco-lingual* Crown height

0.744 + 0.004 0.863 5 0.007 0.505 * 0.007

0.719 +_ 0.013 0.815 + 0.009 0.480 f 0.012

2nd Molar Mesio-distal* Bucco-lingual Crown height*

0.942 + 0.004 0.938 f 0.012 0.458 k O-007

0.914 + 0.009 0.918 * 0~007 0.414 + 0.009

1st Incisor Mesio-distal* Bucco-lingual* Crown height

0.458 i 0.011 0.449 * 0~010 0.464 rt 0.008

0.424 rf: 0.007 O-408 * 0.010 0.454 + 0.014

2nd Incisor Mesio-distal* Bucco-lingual* Crown height*

0.528 + O-007 O-480 * 0.010 0.478 + 0.008

0.467 + 0.009 0.442 + 0.012 0.454 + 0.010

Canine Mesio-distal* Bucco-lingual* Crown height

0.629 rf: 0.007 0.541 If: 0.008 0.571 + 0.014

0.576 + 0.007 0.501 + 0.008 0.564 + 0.015

1st Molar Mesio-distal Bucco-lingual Crown height

0.816 + 0.007 0.703 rt: 0.007 0.530 + 0.007

0.813 + 0.018 0.699 + 0.009 0.515 If: 0.009

2nd Molar Mesio-distal Bucco-lingual Crown height

0.951 + 0.008 0.879 + 0.008 0.446 k 0.010

0.950 k 0.004 0.862 t 0.008 0.406 + 0.019

Maxillary teeth

1st Incisor

1st Molar

Mandibular

teeth

* Differences between male and female values statistically significant, at the 5 per cent level. All measurements in centimetres.

T. D. FOSTER,M. C. HAMILTONAND C. L. B. LAVELLE

1036

It can be seen from Table 1 that for all the teeth the dimensions for the greater than those for the females. There were no statistically significant between males and females for the dimensions of the mandibular molars the other teeth, the differences between the sexes for one or more of the measured were significant at the 5 per cent level.

males were differences but, for all dimensions

(2) Dental arch Table 2 shows the mean figures for the various measurements of the dental arch together with the standard errors of the means. In all areas of the arch the dimensions for the males exceeded those for the females, TABLE~.MEANVALUESOFDIMENSIONS OFTHE~~~IANDLENGTHOFTHE DENTALARCHIN%MALEsAND 50 FEMAL.ESINTHEAGERANGE2fTO Male Mean S.E.

3 YEARS

Female Mean S.E.

Maxillary arch width A-A” B-B c-c D-D E-E* Mandibular

0.747 1.705 2.797 3.289 3.868

f * f f f

0.010 0.014 0.024 0.030 0.030

0.717 1.704 2.785 3.260 3.666

+ f f + +

0.010 0.014 0.028 0.035 0.032

0.487 1.371 2.358 3.029 3.550

+ * f + &

0.010 0.013 0.019 0.026 0.024

0.487 1.280 2.202 2.817 3.446

f + + + +

0.006 0.020 0.024 0.024 0.032

l-159 1.859 2.566 3.359 1.501 2.405 1.622

f + + + * f f

0.010 0.014 0.026 0.024 0.017 0.022 0.017

1.154 1.852 2.473 3.238 1.474 2.373 1.572

&- 0.014 f 0.022 f 0.023 + 0.028 f 0.010 + 0.017 + 0.014

0.903 1.450 2.201 3.099 1.436 2.438 1.786

f f + * f + +

0.061 0.081 0.016 0*019 0.014 0.024 0.015

0.842 1.369 2.176 3.053 1.409 2.378 1.779

f f rt + + + *

arch width

A-A B-B* c-c D-D* E-E* Maxillary arch length A-B A-C A-D* A-E* C-D C-E D-E* Mandibular A-B* A-C* A-D A-E C-D C-E* D-E

arch length 0.014 0.017 0.017 0.028 0.014 0.020 0.017

* Differences between male and female values statistically signiiicant at the 5 per cent level. All measurements in centimetres.

1037

DENTITIONANDDENTALARCHDIMENSIONSINBRITISHCI-IILDREN

except for the measurement between the distal surfaces of the mandibular first incisors where the figures were exactly equal. There were statistically significant differences between the sexes at the 5 per cent level, as can be seen from Table 2. (3) Correlation between dention size and arch size Table 3 shows the mean figures for the total dentition size, the total arch length and the total spacing, together with the standard errors of the means and the correlation coefficients between dentition size and arch length. All dimensions for the males exceeded those for the females and, apart from the spacing in the lower arch, the differences between the sexes were all statistically significant at the 0.1 per cent level. The coefficients of correlation between total arch length and dentition size were high for both arches and both sexes, suggesting that large teeth are associated with large dental arches and small teeth with small dental arches. TABLE 3. MEANVALUESOFTOTALDENTITIONSIZE,TOTALARCHLENGTHAND TOTAL SPACINGOFTHE TEETH IN 50 MALES AND 50 FEMALESIN THEAGERANGE2fTO 3 YEARS

Male Mean

S.E.

Female Mean S.E.

Maxilla Dentition size

*3*53

Arch size Spacing

*3-59 f 0.0221 *o-o71 + 0.0091

+ O-0206

3.40

3.44 + 0.0149 o-034 * o-0035

& 0.0154

*3-37 f 0.0175 *3.42 f O-0178 o-044 f 0.0035

3.23 + 0.0106 3.27 of: 0.0107 0.042 + 0.0037

Mandible Dentition size Arch size Spacing

* Differences between male and female values statistically significant at the 0.1 per cent level. All measurements in centimeters Coefficients of correlation

Maxillary arch Mandibular arch

between total dentition size and total arch length Male

Female

o-945 O-982

o-977 o-949

The apparent small discrepancies between the sum of the mean mesiodistal diameters in Table 1 and the dentition size in Table 3, and the fact that in Table 3 the difference between dentition size and total arch length does not quite equal the spacing, were due to rounding off errors.

T. D. FOSTER, M. C. HAMILTON AND C. L. B. LAVELLE

1038

DISCUSSION

Several studies of the dimensions of the primary teeth have reported significant sex differences and in most cases the teeth from males have been found to be larger than those from females. SEIPEL(1946), studying Swedish children, MOORREESet al. (1957) studying North American children and CLINCH (1963) studying British children, all report that the means of measurements in females

and the differences

of the primary teeth in males exceed those

were often statistically

significant.

MC~~RREESet

al. (1957) found that the difference between the sexes was most marked in the primary canine teeth, a finding which was not confirmed by the present study. In contrast to the usual findings in respect of sex differences in primary tooth dimensions, COUGHLIN (1967) reported measurements

of females which were greater than those of males for

primary molars at the intra-uterine The mean mesio-distal

tooth

age of 19-38 weeks. diameters

of the males in the present study were

larger than those found by SEIPEL(1946) and MOORREESet

al. (1957) with the exception in each case of the mandibular second molar which was smaller. All these differences except one were statistically significant at the O-1 per cent level, the remaining one being significant at the 1 per cent level. It should be noted, however, that the measurements of SEIPEL(1946) and of MOORREESet al. (1957) were made on slightly older children than in the present study, and therefore attrition may have reduced the tooth dimensions. In females, the mean mesio-distal tooth diameters in the present study were larger for the maxillary canine and first and second molars, and for the mandibular first incisor and first molar, but smaller for all the other teeth than those reported by SEIPEL (1946) and MOORREES et al. (1957). Again, the differences were statistically significant except for those between the maxillary first molar compared with Seipel’s population and the mandibular second incisor and canine compared with the population studied by MOORREESet al. (1957). It is more difficult to compare the results of measurements of dimensions of the dental arches with those of other studies because of the differences in measurement techniques used. The sex differences found in the present study are similar to some findings of other authors. HOLCOMBE and MEREDITH (1956), measuring the intercanine width in 100 white North American found

the dimensions

children between the ages of 4 and 8 years,

in the males to be greater than in the females. MEREDITH and

HOPP (1956) reported similar sex differences in the width between the primary second molars in 77 subjects between 4 and 8 years of age. COHEN(1940)

measuring 28 North American children between the ages of 3$ and 139 years, found that the anterior segment of the arch was larger in males than in females, but the posterior segment was larger in females than in males. In a study of 500 Swedish children at the age of 4 years, SEIPEL(1946) found that there was more spacing of the dentition in males than in females, a finding which was the same as in the present study. Thus, in the main, the sex differences in tooth size and dental arch size which were found in the present study are similar to those in the other studies mentioned here, with the exception of that of COUGHLIN (1967). The most unexpected finding of the

DENTITION

AND

DENTAL

ARCH

DIMENSIONS

IN BRITISH

CHILDREN

1039

present study was that of the high correlation between primary dentition size and dental arch size. The size of the dental arch is normally considered to be largely dependent on the size of the jaw and the position of the teeth, which in turn is mainly governed by the oral musculature. The size of the dentition has not been thought to be closely related to the size of the dental arch. LUNDSTROM (1955), studying tooth breadth and tooth alignment in the permanent dentition, suggested that any predisposition to large or small teeth was to some extent associated only randomly with a predisposition to large or small jaws. MOORREES and REED(1954), measuring mandibular teeth and dental arches in 72 North American females aged 18 to 20 years, found a lack of association between the size of the teeth and the size of the dental arch, which they concluded was responsible for the crowding and spacing which they found. There are, however, some well recognized differences in the nature of the primary and permanent dentitions. For example, the primary dentition frequently exhibits the “anthropoid spaces” mesial to the upper canines and distal to the lower canines. These spaces have been referred to by LEWISand LEHMAN(1929) and by BAUME(1950). FOSTERand HAMILTON(1968) found them in over 70 per cent of primary dentitions. Such spaces occur only rarely in the permanent dentition. Crowding of the dental arch is also a feature of difference between the primary and permanent dentitions. Many reports have been made of the prevalence of crowding of the permanent dentition in civilized populations, but crowding of the primary dentition is uncommon. FOSTERand HAMILTON(1968) found only 1 per cent of primary dentitions with no spaces in the arch.. Furthermore, CLINCH(1963) found only a moderate degree of correlation between the size of the primary dentition and that of the successional dentition, ranging from 0.26 in the upper jaw of boys to 0.56 in the upper jaw of girls. These features support the view that the primary dentition preserves more characteristics of the ancestral primate dentition than does the permanent dentition (JORGENSEN, 1956; ROBINSON, 1956) and the high degree of correlation between mesio-distal tooth diameters and dental arch size which was found in the present study may be another manifestation of these primitive characteristics and may be the reason for the rarity of crowding of the primary dentition. R&urn&La denture et les arcades dentaires de 50 garCons et 50 jeunes filles britanniques, Bg6s de 29 g 3 ans, sont Ctudiees. Toutes les dimensions de la denture et des arcades dentaires, chez les gayons, sont plus Clevkes que celles observtes chez les filles, B l’exception de la distance entre les surfaces distales des incisives centrales infkrieures. Les diffirences entre les sexes sont souvent statistiquement significatives. Un degrC tlev6 de corrClation est not6 entre les dimensions de la denture et celles des arcades dentaires dans les deux sexes. 11semble que ce fait puisse @tre une des raisons expliquant la rarete des malpositions de la denture de lait. Zusammenfassung-Dentition und ZahnbGgen von 50 mgnnlichen und 50 weiblichen britischen Kindern weil3er Rasse im Alter zwischen 24 und 3 Jahren wurden untersucht. Mit Ausnahme des Abstandes zwischen den distalen OberflLchen der unteren mittleren Schneideztihne waren die MeBwerte fiir alle Dimensionen der Dentition und der Zahnb6gen bei den Knaben gr6l3er als bei den MBdchen. Hiufig waren die Unterschiede zwischen beiden Geschlechtern statistisch signifikant.

1040

T. D. FOSTER.M. C. HAMILTONAM) C. L. B. LAV~LLE Eine hochgradige Korrelation wurde bei beiden Geschlechtem zwischen dem Umfang der Milchzahne und der GrXk. der ZahnbSgen gefunden. Es wird angenommen, daB dies einer der Griinde fiir das seltene Auftreten eng und gedr&ngt stehender Milchzahnreihen sein diirfte REFERENCES

BAUME, L. J. 1950. Physiological tooth migration and its significance for the development of occlusion. 1. The biogenetic course of the deciduous dentition. J. dent. Res. 29,123-132. CHAPMAN,H. 1935. The normal dental arch and its changes from birth to adult. Br. dent J. 58, 201-229. CLINCH, L. M. 1951. An analysis of serial models between three and eight years of age. Dent. Rec. 71, 61-72. CLINCH, L. M. 1963. A longitudinal study of the mesiodistal crown diameters of the deciduous teeth and their permanent successors. Trans. Europ. Orthod. Sot. 202-213. COHEN, J. T. 1940. Growth and development of the dental arches in children. J. Am. dent. Ass. 27,1250-1260. C~LYER,F. 1920. A note on the changes in the dental arch during childhood. Dent. Rec. 40,273-281. C~UGHLIN,J. W. 1967. Sex differences in the prenatal human deciduous molar crown. J. dent. Res. 46,554558. FOSTER,T. D. and HAMILTON,M. C. 1968. Occlusion in the primary dentition: Study of children at 24 to 3 years of age. Br. dent. J. 1X,76-79. HOLCOMB,A. E. and MEREDITH,H. V. 1966. Width of the dental arches at the deciduous canines in white children 4 to 8 years of age. Growth 20, 159-177. JORGENSEN,K. D. 1956. The deciduous dentition: A descriptive and comparative anatomical study. Actu. odont. stand. 14, Suppl. 20. LEWIS,S. J. and LEHMAN,I. A. 1929. Observations on growth changes of the teeth and dental arches. Dent. Cosmos. 71,480-499. LUNDS~OM, A. 1955. Variation of tooth size in the etiology of malocclusion. Am. J. Orthodont. 41, 872-976. MEREDITH,H. V. and HOPP, W. M. 1956. A longitudinal study of dental arch width at the deciduous second molars on children 4 to 8 years of age. J. dent. Res. 35,879-889. MOORREES,C. F. A. 1959. The Dentition of the Growing Child. Cambridge, Harvard University Press. MOORREES,C. F. A. and REED, R. B. 1954. Biometrics of crowding and spacing of the teeth in the mandible. Am. J. Phys. Anthrop. 12, n.s. 77-88. Mooaaars, C. F. A., THOMSEN,S. O., JENSEN,E. and YEN, P. K. 1957. Mesiodistal crown diameters of the deciduous and permanent teeth in individuals. J. dent. Res. 36,39-47. ROBINSON,J. T. 1956. The Dentition of the Australopithecine. Transvaal Museum Memoir 9: Pretoria. SEIPEL,C. M. 1946. Variations of tooth position. Svensk. Tandi. Tidskrift. 39 Suppl.